calculate area of a region defined by holomorphic function

Let $f$ be a holomorphic function on unit disk $D$. (a). express the Jacobian of the map $f$ in terms of $f$ or $f'$ (b).Give a formula for the area of $f(D)$  in terms of the Taylor Coefficients of $f$. (c).If $f(x)=z+\dfrac{z^{2}}{2}$,find the area of $f(D)$.  My solotion: (a). According to Cauchy-Riemann equation,I compute the Jacobian of the map $f$ as $|f'(x)|^{2}$.             （b).From the elementary calculus,the area of $f(D)$ can be computed  according to coordinate transform.So $\iint_{f\left(D\right)}dw=\iint_{D}\left|f'\left(D\right)\right|^{2}dz$.But I don't know how to express it in terms of Taylor coefficients.              (c).Followed from the result in (b), Area$f(D)$=$\iint_{D}\left|1+re^{i\theta}\right|^{2}drd\theta=\dfrac{4}{3}$  Are my results valid and what about answer for the second question?


cannot stop network printers are being automatically added

I am trying to suppress network printers showing up under Settings/Devices/Printers on my Ubuntu 17.10 (Gnome) desktop. It's my desktop in my office and all the printers in this building appear under Settings/Devices/Printers.  I have edited /etc/cups/cups-browsed.conf as:  BrowseRemoteProtocols none BrowseLocalProtocols none BrowseProtocols none   and restarted the service.  $ sudo service cups-browsed restart     But if I go to settings/Devices/Printers, I still see all the network printers.  Same even if I log out and then log in, or restart the system.  But it is not that the modification to the cups-browsed.conf file is reset on reboot.  If I manually remove the printers from the Settings/Devices/Printers list (by clicking the gear button next to the "No Active Jobs" and Remove Printer), they are removed but come back on my next visit to the Printers tab. I think it is not intended that the "remove" operation is effective only while I stay inside the tab.   If I stop the cups-browsed as:  $ sudo service cups-browsed stop  or  $ sudo systemctl disable cups-browsed   Settings crashes and on re-opening the Settings/Devices/Printers tab, all the printers are again there.   For your information, there is only one printer visible in  or in some of the printing dialogs. However, for example, the printing dialog in Chrome would show me tens of network printers.   How can I stop the system searching for network printers everytime I open Settings/Devices/Printers, or a printing dialog in Chrome?


I am using Centos and want to use sudo command to run as root. But after input the root password, it always prompt to ask me input the password again. I am pretty sure the password is correct since I am able to su - to switch to root then run the command. But I can't run the command by sudo. What wrong with it? Whether I need to configure anything?  Below is an example when I run sudo ls command. I am pretty sure that I have input the correct password.  $ sudo ls [sudo] password for cooltoo:  Sorry, try again. [sudo] password for cooltoo:  Sorry, try again. [sudo] password for cooltoo


How can I solve the 100% disk usage issue in windows 8?

I just want to know how I can solve the disk usage issue that i encounter while using windows 8?


How does current flow from the emitter, through the base and to the collector in a NPN transistor?

So, I understand that for a NPN transistor to work the emitter-base junction needs to be forward biased and the collector-base junction needs to be reverse biased.  I understand how current flows from the emitter to the base when forward biased, but I can't seem to wrap my head around how it flows from the emitter, through the base, and into the collector.  From what I understand about the depletion region of a PN junction diode, when forward biased, the electrons in the N-type material are repulsed by the negative charge of the supply (say a battery) and the holes in the P-type material are repulsed by the positive charge from the supply, thus narrowing the depletion region and allowing electrons to flow from the N region to the P region.  I also understand that the holes and electrons are attracted to the source charges when reverse biased, widening the depletion region and blocking any electrons from flowing.  What I don't understand is what happens to the depletion region of the collector-base junction that allows electrons to flow from the emitter to the collector even though the collector-base junction is reverse biased.  Take a simple common emitter circuit for example.  I apparently am not cool enough to post pictures yet so you'll have to use your imagination.  So pretend we have the base connected to the positive terminal on a 1v battery (Vbb).  The collector is connected to the positive terminal on a 10v battery (Vcc).  The emitter and both negative terminals are connected to ground.  Also pretend that there is some kind of current limiting.  How does current get from the emitter through to the collector?  I can see how they are at different potentials, but I don't understand how this overcomes the reverse biasing of the collector-base junction.  Can anyone tell me what actually happens at the junction to allow current flow and how changing Vbb will affect that current?


I am traveling with my single entry Schengen visa, 68 days duration, to Greece for 40 days and to visit Paris for 5 days. Will that be okay?


How can I check if a string contains only English uppercase and lovercase letters and '|' characters?

I bag your pardon but I'm in need of any help. I must check String instance in C#. The String must contains only uppercase and lowercase English letters and '|' characters. How can I do this checking with Regex class in .NET Framework 4.5.? Suppose I got the String from Console:  String _processedString = Console.ReadLine();   How can I check it to according to above mentioned conditions?


Can an Indian national in F1 and B1/B2 visa travel to Mexico?

Can an Indian national travel to Mexico in F1 visa?I also have an B1/B2 visa but I am residing in US currently in F1 status. And what about people with H1B visas?


On tips an tricks you don't handle page control click. Dot is changed, but not page   App Version: 1.6.2.5 Device: iPhone 7 Plus OS Version: Version 10.2 (Build 14C92)


Can I travel to Australia on a business trip using my tourist stream visitor visa?

I know it has been answered here that you can travel as a tourist on a business stream of subclass 600.    But another online source suggested otherwise that the purpose of your trip must be that of the stream you've been granted a visa for.    Also on my grant, it is stating clearly it is on a "Tourist" stream. So I'm a little worried if I should be applying for another one of a "correct" stream or not. Anyone on a similar situation recently or got any official quote from the Aussie immigration?


Which is correct?  1) Has their board voted yet? 2) Have their board voted yet?  Or does it depend whether we are using American English (Has their board . . .) or British English (Have their board . . .)?  Thanks.


Vintage sci-fi short story: Telepaths, Aliens and Cats

Looking for the title and author of a sci-fi short story wherein an Earth spaceship with telepathic crew encounters an alien spaceship. The telepathic crew try to convince the aliens that the ship's cat is in charge...


Real function, satisfying $\frac{\mathrm{d} }{\mathrm{d} x}f(x_0)<1+f^2(x_0)$

Given $ f(x):[a,b]\rightarrow \mathbb{R}$, with $b-a\geq 4$ and $f(x)$  is  differentiable in every point of interval $(a,b)$.  How can I prove that there exists $ x_0\in (a,b)$ , satisfying $$\frac{\mathrm{d} }{\mathrm{d} x}f(x_0)<1+f^2(x_0).$$  I have no idea how to do it((


Jokes where you replace a word with something unrelated but similar sounding

So a friend of mine always works this type of joke into normal conversation and I always get a kick out of it.  Example:     Person 1: Why are you always hogging the TV remote?   Person 2: Because I am shellfish!   Obviously shellfish is not the correct word for that context, but it sounds similar enough that it works.  Basically what kind of joke is this called or what use of word replacement is that called?  P.S. Not required for a good answer, but if I wanted to respond to someone who has done this to me with the term "Grape job" what would be a good comeback/response?  I was thinking "well orange you nice", but feel like there is a more epic comeback that I just don't know of!


Can you use meta-magic/sorcery points twice in a turn?

Example: You use Quicken Spell to cast a leveled spell or cantrip as a Bonus Action, you then use your Action to cast a cantrip along with using Transmute Spell to change the cantrip's damage type. Is this an ok thing to do? LMBC:You're using two meta-magic options on two different spells in one turn.


How do you determine the amount of Linux system RAM in C++?

I just wrote the following C++ function to programatically determine how much RAM a system has installed.  It works, but it seems to me that there should be a simpler way to do this.  Can someone tell me if I'm missing something?  getRAM() {     FILE* stream = popen( "head -n1 /proc/meminfo", "r" );     std::ostringstream output;     int bufsize = 128;      while( !feof( stream ) && !ferror( stream ))     {         char buf[bufsize];         int bytesRead = fread( buf, 1, bufsize, stream );         output.write( buf, bytesRead );     }     std::string result = output.str();      std::string label, ram;     std::istringstream iss(result);     iss >> label;     iss >> ram;      return ram; }   First, I'm using popen("head -n1 /proc/meminfo") to get the first line of the meminfo file from the system.  The output of that command looks like     MemTotal:       775280 kB   Once I've got that output in an istringstream, it's simple to tokenize it to get at the information I want.  My question is, is there a simpler way to read in the output of this command?  Is there a standard C++ library call to read in the amount of system RAM?


I’m interning at a small software company and trying to set up a local server. I’ve found two old machines that are available for use, running Windows XP and Windows Server 2003.  However, no one knows the passwords for these machines. Is there any way to reset the user accounts without any OS installation discs?


Schwarzschild Radius of the Universe Part 2

There seems to be some confusion as to what I am asking, so I am editing this for clarity.  I know the universe is not a black hole.  But if I could take all of the matter, (seen and unseen including dark matter) and condensed it down until I made a black hole, how big would the Schwarzchild radius be?  I used the online  and got a Rs of 922,849,991,811,114,802,777,336,648 miles or 156,983,977,244,214.0625 LY which seems WAY too high   I have worked 80+ hours this week so my math may be off but $10^{55}$ grams is $10^{52}$ kg's, right? So is there a way to calculate the Rs of the observable universe? If for nothing else other than S&G? Would it be a straight forward calculation? or does the mass of the universe cause issues due to the size?


New release was released at 21 April, but I can't update yet. I have Ubuntu 14.04.4 LTS but   do-release-upgrade Checking for a new Ubuntu release No new release found   If I add -d flag it found new release but I can't understand why need this option because I want update from LTS to LTS. It's because 14.04.4? Or this update is not yet available?  Every other questions told to add -d option, but from LTS to LTS should update without this options. I'm right?


What's the proper distance from the event horizon to the singularity?

How far away is the event horizon of a (Schwarzschild) black hole away from the central singularity for a radially infalling observer starting with $v=0$ somewhere outside the black hole? After crossing the event horizon, such an observer hits the singularity in a finite time, hence such an observer would also assign a finite distance from the horizon to the singularity.  "Crossing the horizon" shall mean that the observer moves from outside the black hole (there are future world-lines, including non-radial and non-freefalling ones, that do /not/ hit the singularity) to inside the black hole (all future world lines hit the singularity).  The radius of a black hole is defined as follows:  Take a ball $B$ in flat (Euclidean) space that has the same surface area like the event horizon of the black hole.  Then the Schwarzschild radius of the black hole is defined to be the radius of $B$.  I'd guess that the so defined Schwarzschild radius is not the same (smaller?) like the proper distance from the event horizon to the center, but what is the ratio of these two values exactly, for example in terms of the mass $M$ of the black hole?  [EDIT]: Clarified that it's for a free falling observer.


How to share .bash_profile between different users in the same group?

I have searched by google but cannot find a right solution.The scenario is like this: in my mac, there are two users, lets say user1, user2. these two users are in the same group, which is staff actually.  Now in user2, there is a .bash_profile for user2's terminal, can i share this profile with the user1? I know i can copy one from user2 to user1. but if i copy one, when there is something changed in user2, i have to copy it again. I wonder whether there is a way to share it with user1?


Why is Skype Startup sound scratchy/grainy?

When I start Skype, the Startup sound sounds like that my speakers is going to break any time (kind of like nails scratching a blackboard).  But when I go to /usr/share/skype/sounds to find the startup sound, I opened it and the file doesn't sound anything wrong.  How do I fix this?  It sounds bad no matter how I start it.


In symmetric searchable encryption are the algorithms public?

If a user (other than the data owner) possesses the secret key in symmetric searchable encryption scheme are they able to run the trapdoor algorithm, or is this not publicly available?


Isomorphism between two models of Hilbert's Axioms with different notions of congruence

I've been reading about Hilbert's Axioms of geometry, and I have two models on $\mathbb{R}^2$ which satisfy the usual axioms of incidence, betweenness, and congruence.   The first model has a distance function given by  $$ d(A,B)=|a_1-b_1|+|a_2-b_2| $$ where $A=(a_1,a_2)$, $B=(b_1,b_2)$, and two segments $AB\cong CD$ if $d(A,B)=d(C,D)$.  The second model has a distance function given by $$ d(A,B)=\sup\{|a_1-b_1|,|a_2-b_2|\}, $$ and again $AB\cong CD$ if $d(A,B)=d(C,D)$.  The author claims that these two models are isomorphic in that there is a bijection between the sets of points in $\mathbb{R}^2$ that preserves lines, betweenness and congruence. I've been toying with it for a while, but it seems to me that the notions of congruence in particular are too different.   For example, in the first model, if $A=(0,0)$ and $B=(2,1)$, and $C=(2,0)$ and $D=(5/2,5/2)$, then $AB\cong CD$ since both segments have length $3$. To preserve congruence, I suppose two segments are congruent if the maximum of the displacement along the $x$-axis or $y$-axis by traveling along one segment is equal to the maximum of the displacement along either axis when traveling along the other segment. In this sense, how could you shape the segment $CD$ so that the maximum of the displacements along either axis is the same as the maximum of the displacement for whatever the image of $AB$ is?  In the first model, $AB$ is congruent to any segment which is the hypotenuse of triangle with legs that sum to $3$, and this sum could split into any two terms. I just don't see a function that could handle all these possibilities at once. Does anyone know of a particular isomorphism between these two? Thanks.


Why is it accepted practice to downvote questions needing migration?

Every day, people post questions on Stack Overflow that need migration to SF, SU, or meta (which, by the way, sucks since a lot of those people don't have access to SU yet). People seem to have a tendency to downvote these questions, even if it isn't necessarily a "bad" question (which is when downvotes are sanctioned, correct?).  Why is this?


How do I fix EXCEPTION_ACCESS_VIOLATION on Minecraft?

When I try to join a massive server the minecraft client crashes with this error: EXCEPTION_ACCESS_VIOLATION. Anyone know how to fix this? Here's my log:  This is not a duplicite because it is only when I join a server.


How's it fair for a moderator to delete my account and dissociate my questions and answers?

Edit I found the email that proves a moderator deleted my account. And nobody appears to believe me before? Even if you suspend me, why dissociate my questions and answers? How can I manage or track them, or accept answers?  Original  Moderator messaged me at Personal Finance S.E. How am I supposed to see if when they deleted my account? When I click on "moderator message", I get 404 not found page.  Why is this being down-voted?   Many people don't believe me that a moderator deleted my old account.  Yesterday when I logged on, I saw "Join this community", but I never deleted my Money account. I then clicked "Join this community" to see what happened.  Screen shot beneath undeniably proves this wasn't my old account when I asked at least 5 questions. It's unquestionably false that "you have not asked any questions."  Please reinstate my old account? I want to keep track of my posts.   I can't post on Money Meta. Please don't betray private details.    and:


Require reason for post deletion and un-deletion?

Could we have a method of explaining why we think a question or answer should be deleted?  It could work identically to closing a question, maybe with an additional text-input box (like the "Requires Moderator attention" flag option) to provide additional info because the reasons for deletion should really be more specific..  For example, "exact duplicate" doesn't explain to me the user has re-posted the same question, thus, it should definitely be deleted (not just left closed). Like with close-messages, these reasons would be listed under the deleted item (or answer).   I don't think comments are suitable, as they can be a pain to quickly.. "extract" deletion reasons from them - I have to scan through the comments, and they may all be irrelevant.  Equally, for un-deletion, it'd be useful to know why another user thinks a question should be restored. For example "new user deleted the question after they accepted an answer", or "Jeff went insane and started deleting any questions with the letter O in it".  I think requiring un-deletion reasons is possibly more important, since commenting is disabled on deleted questions - we have no way of explaining why we think it should be restored


How can I intuitively understand the Boltzmann factor?

It is known that for a system at  described by the , the probability of being in a state of energy $E$ at temperature $T$ is given by the : $$ \tag{1} P(\text{state with energy } E) \propto e^{-E/kT}. $$  I have no problems with the mathematical derivation of this result, but I do wonder if there is a way to understand what (1) means intuitively.  In other words: Is there a way to "guess" that the correct distribution for such a system is given by (1), using solely physical arguments?


How to show my links in structured way like Amazon do

Can you please tell me how links like Books EC2 appear in search results associated with Amazon.com? How can I do similar with my site's main section?


how can you draw inside a shape in preview app?

If try to draw anything inside a shape it gets selected instead, the cursor turns into hand from pen. So basically how can you draw shape on/inside another shape?


Permission denied for disc drive accessed from Xournal++ app

I want access PDF data from within Xournal++ app. I have system SSD disc and another disc mounted as /mnt/data. When in try open /mnt/ from Xournal >>File >>Open and navigate filesystem to /mnt/.. it says Could not read the content of mnt, error opening directoru '/mnt': Permission denied. From terminal:   /mnt$ ls -lsh      4,0K drwxrwxr-x 2 root  root  4,0K pro 13 22:35 cbadd893-26d8-44e2-8abc-caa9da58ec11   4,0K drwxrw---- 9 coral coral 4,0K led 22 20:12 data  Can some one help?


Is the Collatz function $x\mapsto\dfrac{3x+1}{2^{\nu_2(3x+1)}}$ continuous on $\Bbb Z_2^\times$? Let $\Bbb Z_2^\times$ be the 2-adic units. Then e.g. $3\mapsto\dfrac{10}2=5$ Attempt Here's what I know:  The function above can be thought of as a map $x\mapsto3x+2^{\nu_2(x)}$ on all of $\Bbb Z_2\to\Bbb Z_2$ which descends to the quotient map $x\mapsto\{2^ix\in\Bbb Z_2:i\in\Bbb Z\}$. Since $x\mapsto3x+2^{\nu_2(x)}$ is continuous and the function $x\mapsto\dfrac{3x+1}{2^{\nu_2(3x+1)}}$ descends to the quotient, it must too be continuous on $\Bbb Z_2/{\sim}$ However, I think $\Bbb Z_2/{\sim}$ isn't homeomorphic to $\Bbb Z_2^\times$.  If it were, I could answer in the positive.  There's an obvious bijection between them but I think $\Bbb Z_2/{\sim}$ has the trivial topology because every element is arbitrarily close to $0$.  So the trivial continuity in $\Bbb Z_2/{\sim}$ says nothing of continuity in $\Bbb Z_2^\times$.


Let $f(x) = \sqrt{x^2-3x}$ and $g(x) = x$. Calculate the following limits, showing all working.  I've done the first two -   $$\lim_{x\to0}f(x)\\ =\lim_{x\to0}\sqrt{x^2-3x}=0$$  $$\lim_{x\to-\infty}\frac{f(x)}{g(x)}\\ =\lim_{x\to-\infty}\frac{\sqrt{x^2-3x}}{x}=\sqrt{1-\frac{3}{x}}=1$$  How do I calculate this one?  $$\lim_{x\to+\infty}(f(x)-g(x))$$


What is the easiest way to install ubuntu

I have a desktop 32bit Windows computer in which i am trying to install ubuntu. I haven't used this computer in years! The software is a little outdated and i was trying to fully turn it into an ubuntu machine.   Does anyone know whats the easiest way to do this? I tried downloading a disk image and using wubi but it didn't work maybe i did something wrong?


Why didn't Dumbledore simply cut off his hand and make a new one?

Firstly, in the Deathly Hallows when Harry was re-living Snape's memories from the Pensive he saw Snape confining the curse to one hand on Dumbledore.  Secondly, Dumbledore is known to be a wizard of equal or of greater skill than Voldemort. Voldemort was capable of making a new hand for Pettigrew after he cut his off so that Voldemort could be revived.    Therefore logic dictates that Dumbledore should be capable of doing something similar, if I am right.   I have thought about it but I can't find any reason why Dumbledore didn't remove his cursed hand and grow a fresh one in its place.


The answer to this question should really focus on the either proving or disproving the points below and stating a summary or conclusion to your answer which states how you think the evidence more strongly aligns.  The first point would have to be whether it would work at all.  How would you cast a spell from two wands? Would you use them in separate hands or together? You do not need to answer these smaller points in your answer they are just my own thoughts.  The second point would have to be whether it would actually affect the power of the spell  As we all know (or at least I hope you do) the wand is used to focus magical energy so really would we not end up with a larger and less focussed point for magical energy?  Would you actually be able to cast one spell that went to two separate targets?  This would only be apt for using two wands in separate hands but the coordination required for this would be incredible and possibly take years to learn to do effectively at least.  End of points. Now for some discussion.  Clearly you would need two wands that would be aligned to you, thus the elder wand rears it's ugly head again! As Dumbledore would have had 2 wands at one point, Harry also did after repairing his own with the elder wand but that wasn't his style. Dumbledore out of all wizards could have learnt to use two wands although knowledge and skill was more to his liking that pure power.(The hallows excluded) I am going to imagine that I will gain an answer that will just state no wizard in the books was seen to do this so it isn't something that will happen.     How would using two wands work?


What's the purpose of capacitors in parallel

In my school textbook it is written that the capacitor acts as a filter, that is, it decreases the fluctuations in the potential difference across the load.    But since all the components are connected to each other in parallel the potential difference across them should be same. So there should be no change in potential difference across the load even if a capacitor is connected in parallel.   Can anyone explain this to me?


Is it technically correct to end a sentence with "Ltd.." or "Inc..", rather than "Ltd." or "Inc."

I just came across this sentence:      ...is expected to take five weeks to repair, according to Aurizon Holdings Ltd. Prices more than doubled last year, topping $300 a ton...   As I'm sure most people do, I come across situations like this one on an almost daily basis, and despite this it almost always throws me off. Because I am so used to the single full stop after "Ltd", "Co" etc. (pardon that pun?) simply representing a shortening of the words "Limited" and "Company", I naturally continue to read at the same pace, without noticing that a new sentence has in fact started, indicated by the capital letter. (In this case the capital "P" on "Prices".) I have to retrace the word.   Is this end-of-a-sentence behaviour simply convention, thus rendering it grammatically correct to rewrite this sentence as      ...is expected to take five weeks to repair, according to Aurizon Holdings Ltd.. Prices more than doubled last year, topping $300 a ton...   This would save me an annoyance! How about everyone else?  The reason I think it would be correct is simple: We use the first full stop to indicate the shortening of the word, and the second to indicate that we are ending the sentence.


Projection matrix that sum to identity are orthogonal

Can anyone help me to show if $Z_1$, $Z_2$, and $Z_3$ are projection matrices (i.e. idempotent and symmetric) and if $Z_1 + Z_2 + Z_3 = I_n$, then we can conclude:  $$\forall  i \ne j \text{ ,} Z_i Z_j = 0$$  It seems to be an easy problem but I was not able to solve it.  Thanks,


How to mitigate bad grade in research on PhD application?

I've just finished my fourth year (out of 5) of biology studies in one of European universities. I have some experience in research and my grades are quite ok (in US scale it would be 3.75, which means I'm in 5% of the best students in my university). This year I'm starting my master thesis and I expect it to be rather successful - I have interesting topic and good supervisor, with whom I have good contact. This year I'm also starting new studies in electrical engineering and I would love to work in biomedical engineering.  There are several PhD programmes I would like to join abroad (mainly US, UK and Germany). However, I have just got my grade for a research project from spring semester, which is really bad (C+). It is my only grade lower than B, but since it's in research (actually, it's my only grade in research), I'm afraid that it might be a big obstacle in admission process. I'm not a kind of person who blames everyone for my failures, but this time I cannot explain it in any other way than bad supervisor who didn't like me. I've learnt many methods during this project and I've done the worst job for the research group. I've also learn a lot about research in general by seeing my supervisor's mistakes. That is why I'm really happy about this experience, but it doesn't change my grade.  My question is: is there anything I can do to make this grade seem less important or to explain it to admission committee? I'm pretty sure that "Supervisor didn't like me" is not what they want to hear.


UV mapping - nothing shows in UV / Image Editor

When I try to unwrap my mesh, nothing shows up in my UV/Image editor window.  I have tried simple and complex parts, imported and native mesh, all same result. Nothing shows up when I hit unwrap.


Dimensions of Scale (Gamma) and Offset (Beta) in Batch Norm

While implementing Batch Normalization for a particular layer 'L' with 'n' hidden neurons/units in a Neural Network, we first normalize the Activation values of that layer using their respective Mean and Standard Deviation, and then apply the Scaling and Offset factor as shown:     X-norm = (X - mu)/sd X' = (Y * X-norm) + B       where    mu = mean of X and it is a (n,1) vector          sd = standard deviation of X and it is also a (n,1) vector         X = Activation values of layer 'L' with dimension (n,m) if mini-batch    size = m   X-norm = normalized X with dimension (n,m)   Y = Gamma / Scaling factor   B = Beta / Offset factor   Now my question is, what are the dimensions of Gamma and Beta ? Are they (n,1) vectors or are they (n,m) matrices ? My intuition says that since they somewhat are analogous to the Mean and Standard Deviation, they should be (n,1) vectors.


Drag files out of Browser and into filesystem

I understand that Gmail users in Chrome can drag attachments out of their email and into a sensible place in their filesystem (rather than what normally happens, which is that you get a link on your desktop)   Is it possible to replicate this behaviour in general? In particular, say, on Firefox? It would be extremely useful to be able to drag links out of webpages while browsing...


What is the nonparametric variant of multivariate ANOVA with more than one one factor (and with interactions between factors)?

I analyze real data where assuptions of classical multiway (more than one factor assumed) MANOVA (more than one response variable) are not met (normality, equal variances). Is there any nonparametric variant? Note that Friedman test in only alternative to repeated measures ANOVA, not to more general multiway MANOVA with interactions.


Particles can be at the same time in two places. Why?

I am not a physicist, but I was wondering what observation led to the conclusion that a particle can be at two (or is it multiple) places at the same time?


How do I join on a function in MS Access?

I am trying to add a function to my JOIN condition in an MS Access query.  As a simplified example, consider that I have:  tblChildand tblParent and tblGrandparent  tblChild has both a nullable ParentId and GrandparentId depending on which one is known. I'm trying to write a query to take the more specific relationship provided. If this were TSQL it would be:  SELECT     columns FROM     tblChild AS c LEFT OUTER JOIN     tblParent AS p         ON p.[Id] = c.[ParentId] LEFT OUTER JOIN     tblGrandparent AS gp         ON gp.[Id] = COALESE(p.[GrandParentId], c.[GrandParentId])   but I can't figure out how to get a COALESCE style function into the JOIN condition in Access. Here is what I would have expected to work:  SELECT     columns FROM     (tblChild AS c LEFT OUTER JOIN     tblParent AS p         ON p.[Id] = c.[ParentId]) LEFT OUTER JOIN     tblGrandparent AS gp         ON gp.[Id] = Nz(p.[GrandParentId], c.[GrandParentId])


Once I reach 15 reputation, will my old votes be taken into account?

Users below 15 reputation can't effectively vote. It says:     Votes cast by those with less than 15 reputation are recorded, but do not change the publicly displayed post score   Does it mean that they will take effect after I reach 15 reputation or because they were cast before, they're recorded but ignored?


Book ID: 70s-80s novel about boy that goes to a space academy

Random things I remember about the book:   The boy is abducted from Earth to join an intergalactic space school or academy. I remember a scene near the beginning: he saw a young girl and was mesmerized by her, but was suddenly stopped by another student/cadet/teacher saying "be careful, they eat their own". The girl later has some sort of breakdown and they are forced to wipe her memory and return her home. The protagonist remarked how they operated on his tongue so he could speak the common language.  In another scene the aliens had removed the bacteria from under his arms saying that the smell bothered the other people and offered to return it.  I think the cover was vintage 70s-80s and had a drawing of the boy in a space suit with a few of the other students standing in a distance behind him.    I don't remember what the plot was. It may have just been how he was settling in to the new life.   It it not the following books: Ender's Game, Pattern's of Chaos, The Last Starfighter, Tompopaageo


How can I know the exact number of downloads for an app on Google Play Store?

I need to know the exact number of downloads (count, not range) for my app hosted on Google Play Store, is it possible?


The onchange event not working. Select dropdown coming from the controller

I have a select dropdown which comes from the controller using JSON and displaying on the view page.  Now my on change event is not working. If I added a select drop down direct on view then it's working but which is come from the controller that is not working.  Controller  $code.= '   I have more html code here   <select name="yearDropdown"  class="form-control dropdownDuration">  <option selected disabled >Select duration</option>    <option value="12m" <?php if($product['options']['duration'] == "12m"){ echo 'selected="selected"';} ?> >1 Year</option>  <option value="6m" <?php if($product['options']['duration'] == "6m"){ echo 'selected="selected"';} ?>>6 months</option>  </select>  I have more html code here           ';   on change script  $('.dropdownDuration').change(function () { alert('hello'); });   AJAX  $(document).ready(function(){ $.ajax({ url:baseUrl+"/Member_controller/Section",        // context: document.body,        dataType: "json",         success: function(data){            //alert("done");           //alert(data);            $('#ProcessModel').html(data);         }});   });  view


How to get two computers on the same LAN to connect to the c$ share of each other? (no homegroup)

I'm trying to do file sharing "the old style" between two computers in my network.   I'm trying to do "Start -> Run", type in \hostname\c$ or \IPAddress\c$, log in with the user and password, and access the share.  I don't want to set specific permissions when sharing specific folders. Simply going into c$ with an admin user, which gives me access to everything.  This was working perfectly fine until I had to reinstall one of them and now it doesn't work anymore.   Once computer is Windows 7 Ultimate, the other is Windows 8.1 In both "Sharing Wizard" is turned off. In both, Firewall is off Both are outside a homegroup. In both, the username I'm using is the main user of the computer, who happens to be an administrator. It has the same password in both. I've tried entering the username as either just the username, or "othercomputer\username" (this wasn't necessary before). It still doesn't work.   Every single time I need to get this to work it's a matter of trial and error until it happens to work and I never know why.  Could you give me the list of things that I need to make sure are set in a certain way for this to work?  Thank you


this question is indeed trivial, but I haven't found any answer to it online. I'm for the first time using the Beamer environment to make a presentation. I'm using the Cambridge US theme, but I want to change the color of the theme to structure, as seen in this . I found quite a lot of information on how to change the color of specific elements within the Beamer environment, but I simply want to change the color of the entire theme.  The reason for this is I don't like the combination of the red general theme and the blue graphics for itemize.  \documentclass{beamer} \usetheme{CambridgeUS} \setbeamercolor{structure}{}  \begin{document}   \begin{frame}  \frametitle{Introduction}  Blablabla  \end{frame}  \end{document}   Thanks!


I have a biased coin with 2/3 chance of heads (and thus 1/3 chance of tails). Question is: given that there was at least one head in 3 flips, what is the probability that there is only 1 head?  How would I solve this?


How to print sign "-" instead of "." using ?

I use the HTML code:

first item

second item

third item

     How can I print sign "-" instead of dot using OL HTML tag like example:   1 - first item 2 - second item 3 - third item   How can I implement it in HTML format.


Entering U.S. exactly on the day of visa "expiration date"

I'm a bit surprised from my US Visa. I plan to go to a conference on 3rd of April. Amazingly though, the visa expiration date is written as April 3rd.  So what does that mean. Can I enter the US on April 3rd? or should I enter one day earlier?


array package: problem with >{declarations} in preamble: Extra alignment tab has been changed to \cr

I have a document that uses both the longtable and the array package. At first I ascribed the problem to an interaction of both. After testing, it seems array is the only culprit.  Here's a minimal example.  \documentclass{article} \usepackage{array} \begin{document}  \begin{tabular}{p{0.4\textwidth}>{\raggedright}p{0.4\textwidth}} 1 & a \\ 2 & b \\ 3 & c \\ \end{tabular} \end{document}   It produces the error  ! Extra alignment tab has been changed to \cr.


I'm a standard user even though i am the owner

I'm sorry if this questions was asked before! When i wanted to delete a folder it gave me the error "You'll need to provide admin permission to delete this folder" and i was pretty confused cause i am the only owner.   So i went to Control Panel>add or remove acconts and I saw that there was my account, and and admin account called administrator that i made it by mistake and i can't delete it! i can't change my account type. what should i do??


Getting a custom block image field URL in the block Twig template

I have a custom block containing a text field and an image field. I would like to render the block so that the image's URL can be defined as a data attribute of the block's wrapper div so that it can be used by a javascript function to create a parallax background effect behind the text field.  If I make a template file block.parallax.html.twig, I am able to render the image HTML.  {{ content.field_parallax_image.0 }}   However If I try to get the actual image URL, nothing is returned  {{ content.field_parallax_image.0['#url'] }}   If I dump the #item keys  {{ dump(content.field_parallax_image.0['#item']|keys) }}   I am able to get target_id, alt, title, width and height values, but I can't find the URL defined anywhere.  I have also tried to see if I could find anything useful in the block preprocess function but the field_parallax_image #url field in the variables is also empty  function mytheme_preprocess_block(&$variables) {     if( isset($variables['content']['body']['#bundle']) && $variables['content']['body']['#bundle'] == 'parallax'){         $variables['img_url'] = $variables['elements']['content']['field_parallax_image'][0]['#url'];     } }   Is there a way I can get this URL?


Performing commands in PowerShell using C#

I am writing a plug-in for a software using C#. My plug-in generates a directory, containing a couple of text files, that I need to transfer to a computational cluster. At the moment I am transferring the files manually with the PowerShell (or the Ubuntu plug-in for Windows) using "scp -r -P location/on/windows location/on/cluster", but I would like to do this step automatically by including it in my plug-in.  I have looked around online for guidance and I have found some helpful documentation, but I am still quite lost.   So far I've managed to open the shell, but how to add a sequence of commands I still don't understand.    if(x)   }       OpenPowerShell(@"C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe");   }     static void OpenPowerShell(string path)   {     Process.Start(path);   }   Could someone please help me out with this or point to some helpful documentation?  Thanks, David


In the close vote review queue, when you switch to look at a duplicate question, the close button is broken

It appears that the recent UI change for the close vote review dialog introduced a bug when it concerns suggested dupes. Reproducing in Firefox 78.0.1 (Mac OS). In this dialog there are two tabs, "Question" that shows the question to be closed, and "Duplicate" that shows the suggested duplicate. When the latter tab is active, the "Close" button produces no action though it is not disabled.  Only when on the "Question" tab can you successfully vote to close the question.   There seems to be an uncaught exception raised by JQuery, when called from review.en.js:  SyntaxError: Document.querySelectorAll: '.close-question-link[data-questionid=63380604]' is not a valid selector  Looks like the original question ID may be lost when switching to the "Duplicate" tab.


How can I get chewy chocolate chip cookies?

My chocolate chips cookies are always too crisp. How can I get chewy cookies, like those of Starbucks?    Thank you to everyone who has answered. So far the tip that had the biggest impact was to chill and rest the dough, however I also increased the brown sugar ratio and increased a bit the butter. Also adding maple syrup helped.


How to remove xfce4 and switch to KDE under vncserver?

I have installed tigervnc server and xfce   sudo apt install xfce4 xfce4-goodies   and was working for some time. Then I decided to try KDE and did  sudo apt install kubuntu-desktop sudo apt remove xfce4   But nevertheless I have xfce4 on vnc screen. How to remove it and switch to KDE?


How to evaluate $\lim_{n\to \infty}\left(\sqrt{x^2+4x\ +1}-x\right)$

$$\lim\limits_{n\to \infty}\left(\sqrt{x^2+4x\ +1}-x\right)$$   The answer is $2$ but I don't know how to evaluate it


Consistency of an order statistic in exponential distribution

I have two questions.   1) If $X_1,X_2,X_3,...,X_n$ constitute a random sample of size $n$ from an exponential distribution, show that $\bar X$ is a consistent estimator of the parameter $\lambda$.    This is my attempt: Mean of exponential distribution is $\lambda^{-1}$. Thus by central Limit theorem $E(\bar X)=\lambda^{-1}$. Using mean square consistency, if  $\lim_{n\to \infty} E[(\bar X -\lambda )^2]=0$ then $\bar X $ is consistent for $\lambda$. Since $$ E[(\bar X -\lambda )^2]= E[(\bar X)^2]+E(\lambda)^2-2\lambda E(\bar X) , $$  I get $$ \lim_{n\to \infty} E[(\bar X -\lambda )^2] =    \lim_{n\to \infty} {2 \over \lambda ^2 }+\lambda^2-2 . $$ Clearly this is not equal to $0$. How can I show this is consistent? I tried using Chebechev inequality as well. But even using that I couldn't.    2) Is $X_{(n)}$ a consistent estimator for $\lambda$? If $P[|X_{(n)}-\lambda|<\epsilon]$ approaches $1$ as $n$ goes to infinity for all $\epsilon > 0$ then $X_n$ is a consistent estimator for $\lambda$.    The probability density function of $X_{(n)}$ is $f_n(x) = n \lambda e^{-\lambda x}(1-e^{-\lambda x})^{n-1}$,  for $X>0$.  Thus \begin{align*} P[|X_{(n)}-\lambda|<\epsilon]  &= P[\lambda -\epsilon<X_{n}<\lambda+\epsilon] \\  &=P[0<X_{n}<\lambda+\epsilon] \\  &=\int_0^{\lambda+\epsilon} n \lambda e^{-\lambda x}(1-e^{-\lambda x})^{n-1}\\  &= (1-e^{- \lambda X_{(n)} }), \end{align*} where $X{(n)}$ takes values in $[0 , \lambda+ \epsilon]$.  Thus, can I say $\lim_{n\to \infty}[1-e^{-\lambda(\lambda+\epsilon)}]^n=1$?


Need to sum of last column based on pipe delimiter


Is there something in .NET that corresponds to java -Xmx memory size allocation?


I don't know what to do, please help      'E/AndroidRuntime: FATAL EXCEPTION: main                     Process: com.is2all.so2al_ijaba, PID: 13051                     java.lang.RuntimeException: Unable to resume activity {com.is2all.so2al_ijaba/com.is2all.so2al_ijaba.windows_asila}: java.lang.NullPointerException: Attempt to invoke interface method 'int java.util.List.size()' on a null object reference                         at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3103)                         at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:3134)                         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2481)                         at android.app.ActivityThread.-wrap11(ActivityThread.java)                         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)                         at android.os.Handler.dispatchMessage(Handler.java:102)                         at android.os.Looper.loop(Looper.java:148)                         at android.app.ActivityThread.main(ActivityThread.java:5417)                         at java.lang.reflect.Method.invoke(Native Method)                         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)                         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)                      Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'int java.util.List.size()' on a null object reference                         at com.is2all.so2al_ijaba.windows_asila.table(windows_asila.java:204)                         at com.is2all.so2al_ijaba.windows_asila.onResume(windows_asila.java:439)                         at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1258)                         at android.app.Activity.performResume(Activity.java:6312)                         at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3092)'   the code :  public void table() {          handler.removeCallbacks(run);         count=30 ;         rnd = rand.nextInt(mDataList.size());         id = mDataList.get(rnd).ID ;         btn.setText(mDataList.get(rnd).Question);         btn2.setText(mDataList.get(rnd).Answer_1);         btn3.setText(mDataList.get(rnd).Answer_2);         btn4.setText(mDataList.get(rnd).Answer_3);         btn5.setText(mDataList.get(rnd).Answer_4);         count_b = mDataList.get(rnd).ID_answer;         timer();         if (mInterstitialAd.isLoaded() & rnd == 2 || rnd == 4 || rnd == 8 || rnd ==16 || rnd == 32 || rnd == 64 || rnd == 128 ) {             handler.removeCallbacks(run);             mInterstitialAd.show();         } }      @Override     protected void onResume() {         super.onResume();         table();          SharedPreferences savechange =  this.getSharedPreferences             ("savechange", Context.MODE_PRIVATE);         int Point = savechange.getInt("Point",point);         this.point = Point;         btn7.setText("+نقط : "+point);     }


I am running a Samsung Chronos 7 with an NVIDIA Geforce GT 640m graphics card. I would like to utilize this graphics card so that I may use my computer for various computer games. Previously, when I tried to install drivers via the sudo command for downloading the current drivers for my card, Ubuntu would not boot past the splash screen, and eventually "gave up on finding the root". I am starting from a fresh install of Ubuntu 14.04, and I request some help on what to do.


Blender 2.8 API, python, set active object

I'm trying to amend an addon that I made for Blender 2.7X to work with Blender 2.80. The problem is with  bpy.context.scene.objects.active = some_object   This is how I used to set an active object, the problem is, active property was removed in the new API!,reading other Q&As, I found 2 suggestions:  bpy.context.object   and  bpy.context.active_object    The problem is, both of these will return the already active object, but when I try to use them this way:  bpy.context.active_object = some_object   or   bpy.context.object = some_object   I'm getting an AttributeError: property is read-only!  I tried the documentation with no luck!  EDIT:  According to Blender 2.8 WIKI API changes:   bpy.context.scene.objects.active   changed into  bpy.context.render_layer.objects.active   This doesn't work, AttributeError: 'Context' object has no attribute 'render_layer'


I am using ArcMap One-way replication tool to synchronize feature classes from Oracle to MS SQL Server (once a day), but replication only works for the versioned data with move edits to base option as unchecked and only edits or changes from that specific version are synchronized in MSSQL server.   The version of the feature class (Oracle's) in ArcMap is different from the base tables (the one that is shown in Oracle SQL developer), how can I make sure that the data in base table and the one that is shown in ArcMap are same? How can I make sure the edits or changes that are made in either of the version are reflected to the other? How to make ArcMap aware of the changes that are made in base table?


Verifying Ubuntu on Windows 7 (total newbie)

Friends, I would like to specify my question a little bit, cause a lot of you give me suggestions that are already written in this page  www.ubuntu.com/download/how-to-verify  What confused me is that tip in the 2nd step, where it says :      Tip: On non-Linux systems, you might need to download the GPG tools for this next step. To check if you have the GPG tools installed, run the command gpg --version or gpg2 --version.   Now, it's not written WHERE do I have to write these commands. At the beginning in that page it says "These instructions assume basic knowledge of the command line", so I assumed I needed to open a "Command prompt" program for that, is it right ?  I don't understand why isn't it mentioned in that tip, it is really confusing for a newbie like me. And the results that I get when writing these commands in the "Command prompt" are confusing as well. But knowing that the gnuPG has never ever been installed on my laptop I don't expect too much more.  But still it would be good if it was written in that tip what you should see if it's not installed AND that from Windows OS you have to open a Command prompt program to write these commands in.   Previous question  I want to install Ubuntu on my laptop. I downloaded the iso image and now I want to verify it. I currently have Windows 7 as OS on my computer.   In this page www.ubuntu.com/download/how-to-verify in the 2nd step there is this tip that says:      Tip: On non-Linux systems, you might need to download the GPG tools for this next step. To check if you have the GPG tools installed, run the command gpg --version or gpg2 --version.   Now as I understand I need to write gpg --version when I open the command promt program is that right? I tried and it is unrecognized. But it's okay because I have never ever installed it on my laptop. The thing I worry a bit is am I doing it right? Do I need to use command prompt program for this?


In Section 9 of Chapter 6, Lang constructrs for the first time a non-abelian extension as a splitting field $K$ of $X^n - a$ when the ground field $k$ does not contain primitive $n$-th roots of unity $\zeta_n$. He constructs an injective homomorphism of the Galois group $G(K/k)$ into the matrices of type   $$ M=\begin{pmatrix} 1 & 0 \\ b & d \end{pmatrix} \quad \hbox{with}\ b\in \mathbb{Z}/n\mathbb{Z} \quad \hbox{and} \quad d\in (\mathbb{Z}/n\mathbb{Z})^*,$$  where $(\mathbb{Z}/n\mathbb{Z})^*$ the multiplicative group of integers modulo n.  Afterwards, he states in Theorem 9.4 that if $n$ is an odd positive integer prime to the characterstic and $[k(\zeta_n):k]=\varphi(n)$ (i.e, the primitive roots of unity are not in the ground field), then the above homomorphism is, in fact, an isomorphism. Besides, the commutator group is $G(K/k(\zeta_n))$, so $k(\zeta_n)$ is the maximal abelian subextension of $K$.  Lang proves the theorem inductively over the number of prime factors in the decomposition of $n$ (i.e. if $n=9= 3\cdot 3$, then the proof "would take two steps" to complete). The induction start with $n$ prime is written clearly and I agree with it.   Now come the questions:   I do not understand Lang's argument to prove that the commutator subgroup is the subgroup $\begin{pmatrix}1 & 0 \\ b & 1\end{pmatrix}$, $b\in \mathbb{Z}/n\mathbb{Z}$. What is this projection on the diagonal and how does one see that the factor group of the commutator group is isomorphic to $(\mathbb{Z}/n\mathbb{Z})^*$?   By the way, direct computation of $x\, y\, x^{-1}\, y^{-1}$ for two arbitrary matrices $x=\begin{pmatrix} 1 & 0 \\ b & d \end{pmatrix}$, $y=\begin{pmatrix} 1 & 0 \\ c & e \end{pmatrix}$ yields a matrix $\begin{pmatrix} 1 & 0 \\ b(1-e)+c(d-1) & 1 \end{pmatrix}$. As $n$ is odd, $2 \in (\mathbb{Z}/n\mathbb{Z})^*$, so taking $e=1$ and $d=2$, we indeed reconstruct the above-mentioned group.   The second (inductive) part of the proof is a complete mystery to me with virtually every sentence being a Theorem which needs an extra proof. Can someone give me some hints?   2.a. Lang writes $n=p\,m$ and takes $\alpha$ to be the root of $X^n-a$. It is clear that $\beta=\alpha^p$ is a root of $X^m -a$. Now comes the argument "By induction we can apply the theorem to $X^m-a$". I agree that we can apply it here but the result is that $K=k(\beta,\zeta_m)$ is the splitting field of $X^m-a$. In the diagram below, there appears $k(\beta,\zeta_n)$ out of nowhere.   2.b. Now Lang proceeds to apply the theorem on $X^p-\beta$ over $k(\beta)$. Bergman's "Companion" reminds to check that $[k(\beta,\zeta_p):k(\beta)]=\varphi(p)$ before applying the theorem and gives a hint "$[k(\zeta_p):k]$ and $[k(\beta):k]$ are relatively prime". I disagree with this hint. Take $n=21= m p$ where $m=3$ and $p=7$. Then $[k(\zeta_p):k]=\varphi(p)=p-1=6$ but $[k(\beta):k]=m=3$ and both are not co-prime. Can we apply the theorem here at all? Or if so what is the argument? If Bergman's argument is valid, where is the fault in my logic?  2.c. Even assuming that we can apply the theorem in 2.b., then we can say something about $k(\alpha, \zeta_p)$ and not $k(\alpha,\zeta_n)$. How do we proceed to checking everything Lang states in the last section of the proof (basically, everything after the diagram)?  EDIT: I have found the essentially same question


I've recently got Win 8.1 Pro and a new keyboard and mouse(Slimstar c110). The keyboard worked but suddenly  both of my Ctrl keys aren't working.  I tried doing tests and doing shortcuts but they aren't working, I'm almost 100% sure the keys themselves  aren't broken.  Are there any options that could have disabled my Ctrl keys?


SEO/link-juice implications of 'www.' links versus links without 'www.'

I remember reading ages ago that it's a good idea to choose either www.example.com or domainexamplecom as your main URL and then set the other one as a 301 redirect to point to your domain? The reason provided was:  Some people may link to www.example.com Other links may point to example.com  In order to not lose 'SEO link juice', the individual recommended setting up a 301 redirect from one to the other. Has this changed? Is it true? I would have guessed that Google (and other search engines) would be smart enough to whack some code in their algorithm to understand that in most cases www.example.com = example.com?


Grey objects in the material preview and the rendered mode look in Eevee render

In object mode, the objects look normal:  However, when in eevee, the material preview and the rendered mode look like this:  When I zoom or rotate I get this weird outline:  Please note that this is a brand new blender project in the images, but this same issue applies to all my projects. I have already tried setting back my driver but that hasn't worked. I've also tried downloading earlier versions of Blender, but somehow I get the same issue. PC Specs (if that helps): Operating System: Windows 10 Pro 64-bit (10.0, Build 19041) (19041.vb_release.191206-1406) Processor: Intel(R) Core(TM) i5-8500T CPU @ 2.10GHz (6 CPUs), ~2.1GHz RAM: 8GB DirectX Version: DirectX 12 Card name: Radeon RX 580 Series Any help would be much appreciated.


Installing Ubuntu 12.04 on a high-resolution display laptop

I have installed Ubuntu 12.04 with compiz on a 17" laptop with 1920x1080 display. After the installation the fonts are too small. Even if I change the fonts' size the Close/Minimize/Mazimize icons remain tiny, Is tehre any appropriate theme for high-resolution displays? How can I install it?


I'm curious about the storyline for Ra's al Ghul. In the end of Batman Begins, is he dead? But yet Ra's al Ghul appears in the Green Arrow. Them both being DC Comic story lines I'm curious how this is?


Conversion of the Polyakov action into the Nambo-Goto action?

I've read that the Polyakov action using an intrinsic metric $h_{\alpha\beta}$  $$\tag{1} S_P ~=~ -\frac{T}{2}\int d^2 \sigma \sqrt{-h}h^{\alpha\beta} \partial_{\alpha}X^{\mu}\partial_{\beta}X^{\nu} \eta_{\mu\nu}$$  can be converted into the Nambo-Goto action containing the induced metric $\gamma_{\alpha\beta}$  $$\tag{2} S_{NG} ~=~ -T\int_{\tau_i}^{\tau_f} d\tau \int_0^{\ell} d\sigma \sqrt{-\gamma}.$$  How this conversion is done is not further explained in my book so my question is if somebody can give or point me to some more explicit hints how this can be done?


Losing permissions by adding capability?

I observed the following phenomenon that I can not explain. After adding the CAP_SYS_ADMIN capability, unshare is no longer able to write to /proc/self/setgroups.   In fact, writing to this file requires the capability, but that is achieved by changing the user namespace. So why does adding the capability to the parent process prevents writing to this file?  me@myhost:~$ unshare -r root@myhost:~# exit logout  me@myhost:~$ sudo setcap cap_sys_admin=ep /usr/bin/unshare me@myhost:~$ unshare -r unshare: cannot open /proc/self/setgroups: Permission denied  me@myhost:~$ sudo setcap cap_sys_admin= /usr/bin/unshare me@myhost:~$ unshare -r root@myhost:~#   By the way: I am running Ubuntu 16.04.4 LTS with kernel version 4.4 and the version of util-linux (including unshare) is 2.27.1.


How to build a smooth "transition function" explicitly?

It is easily shown that the function $$\begin{cases} \exp \left(\frac{1}{x^2-1} \right) & |x| < 1 \\ 0 & \text{otherwise} \\ \end{cases}$$ is smooth and has compact support in $\mathbb R$. I tried playing with it to find a function with the following properties:  a. $f(x)=0$ for $x \le 0$  b. $f(x)=1$ for $x \ge 1$  c. $f$ is monotonically increasing.  d. $f$ is smooth.  Is it possible to find an explicit formula for such $f$?


How to test any 2 line segments (3D) are collinear or not?

if we have two line segments in 3D, what would be the way to test whether these two lines are collinear or not? (I fogot to mentioned that my line segments are 3D. So, I edited the original post. Sorry for the inconveniences) I wish to check the direction of the lines and the perpendicular distance between them. Does these two factors are enough to decide whether 2 line segments are collinear or not. Thank you in advance.


Covariance of Euler-Lagrange equations under change of generalized coordinates

Suppose I have an inertial frame with coordinate $\{q\}$. Now I define another reference frame with coordinate $\{q'(q,\dot q,t)\}$. I obtain the equation of motion in $\{q'\}$ in two different ways:   First obtain the equation of motion in $\{q\}$ by the Euler Lagrange equation $$\frac{d}{dt}\left(\frac{\partial L}{\partial \dot q}\right)-\frac{\partial L}{\partial q}=0$$ and then rewrite the equation in terms of $\{q'\}$. First transform $L(q,t)$ to $L'(q',t)=L(q(q',t),t)$ and then obtain the equation of motion $$\frac{d}{dt}\left(\frac{\partial L'}{\partial \dot q'}\right)-\frac{\partial L'}{\partial q'}=0.$$   Are the two answers just the same?


Supply the same filename as argument to two commands

On a git conflict, I can currently do:  git diff path/to/some/file.txt   ... after reviewing the diff, usually I want to do:  git checkout --theirs path/to/some/file.txt && git add path/to/some/file.txt   It's painstaking to edit both paths each time, so I'd like to be able to do the following:  git checkout --theirs <ref> && git add path/to/some/file.txt   Where the <ref> refers to file.txt.  Any way to do this in bash?


I want to know about the grammar of omitting pronouns. I've searched for it some times but I didn't find a proper answer.  Actually I want to write in my profile about my education, I want to write "I major in Physics and minor in Biology" but I don't want to use the pronoun "I". Is it grammatically correct to just write "Major in Physics, Minor in Biology"? and whether it is not, how should I express it?


Why can we cast "servletRequest" to "HttpServletRequest"?

In doFilter method, we use the code below to access to session :  HttpServletRequest request = (HttpServletRequest) servletRequest;   But, "HttpServletRequest" extends "servletRequest", so theoretically we should not be able to put father in son.


Can you start a sentence with "especially"?

I have this sentence in a text:      Especially the foreigners are a very important group which requires special treatment and representation.   I feel it should read:     The foreigners in particular are a very important group which requires special treatment...   Can you start a sentence with "Especially"? Why do I get the feeling that there's something missing in the sentence?


Crossposting answers on duplicate questions

What is the consensus or policy on crossposting answers on a single Stack Exchange site or across different Stack Exchange sites? (I searched and found a lot of questions and answers about crossposting questions but none for answers.) I often encounter a situation where:   There are duplicate questions on one or more Stack Exchange sites Some these questions are linked together through the "duplicate questions" notices Some of these questions are locked Possibly some of the questions have good, comprehensive answers   In some of the cases where the above happens, there are sometimes isolated questions without good answers even when good answers exist on some of the questions. In other cases, no good answer exists, but the questions are still scattered. For me, this creates a situation where I'm not sure where to post an answer even if I am confident I can answer a question well.  My question is about what to do in such situations. Is it okay to crosspost the same answer on all the duplicate questions? Is it okay to make one the canonical answer and link to it from the other questions?


Good algorithm to compute the sample mean and variance

I am looking for good (fast, memory efficient, ideally one-pass) algorithms to compute the sample mean and variance.  I have found a technical report by  from 1983 with interesting algorithms. Are there more modern improvements?  EDIT: Added the crucial words "and variance"


Sometimes I have a mathematical formula using, e.g.,  \dot{x} in a footnote but I have difficulties in recognizing the effective presence of a dotted variable (my fault, I know... to quote the poet "That's not the electric light, my friend\\That's your vision growing dim.").  Anyway, is it possible to use a heavier symbol for the dot that is usually used to indicate derivation w.r.t. time when used in a footnote?


What does a logarithmic scale graph express that a linear scale one does not?

...essentially, why would someone want to look at a logarithmic scale graph? What can be derived from a logarithmic scale graph that makes it worthy of presentation in addition to a linear scale version?  At  there is a graph in "linear scale" (the default) and a tab with a "logarithmic" scale version.  Here they are:


TV series in the early 90s about war with robots (or aliens)

There was this series I watched in the early 90s, about a group of soldiers fighting against some androids (or aliens, can't remember).  The enemies definitely looked like androids, but I can't recall if they were robots from Earth or aliens.  The only enemy unit I can remember had wings, with birdy head. There were also terrestrial units.  The enemy's weapons shot lasers. I first thought people were being disintegrated, but later found out they were actually teleported to the enemy's HQ.  I can't remember much more, just that it was on Earth, where all the cities were basically reduced debris and fights would happen through the remains.


How can I recover data from a clicking/dying external drive?

Windows asks me to reformat every time I plug it into my computer, so I fired up Ubuntu via VirtualBox (selecting the external hard drive in the USB settings for VirtualBox beforehand) to see if I can access it there.  Does anyone have any suggestions for me? I have over 1TB of data on this drive and do not want to lose it. When I plug it into an electrical outlet, the light turns on, and when I plug it into my laptop, I can feel it clicking.


the secret of the Tesla letter in The Prestige

In the movie The Prestige, I realized that         Borden has a twin brother who he uses in tricks. Some kind of half life.      But I don't understand anything about that specific letter that Borden gave to Angier. He wrote Tesla on it. What was that about? Is there a possibility that        Tesla made a copy of Borden like Angier?


Singular or plural when there is no plural antecedent?

I am not sure if the singular or plural forms should be used in the following. Some people go for the plural, but it doesn't seem to have a plural antecedent.     Each month, the school holds a party. This event is / These events are/ successful because it attracts / they attract over two hundred students.   I'd appreciate your help.


Is there a way to set an mp4 as an ubuntu wallpaper? Or any other format as long as it is an animation?


Kernel driver not installed (rc=-1908) (chromebook)

The VirtualBox Linux kernel driver is either not loaded or not set up correctly. Please try setting it up again by executing /sbin/vboxconfig as root. If your system has EFI Secure Boot enabled you may also need to sign the kernel modules (vboxdrv, vboxnetflt, vboxnetadp, vboxpci) before you can load them. Please see your Linux system's documentation for more information. where: suplibOsInit what: 3 VERR_VM_DRIVER_NOT_INSTALLED (-1908) - The support driver is not installed. On linux, open returned ENOENT.  I have already downloaded Ubuntu but I'm not sure where to go next. I'm no computer nerd and I'm gonna need people to explain what I should do as if I were 5 year old. For context on why I need this, it is because I'm trying to stream PS4 on discord but the 3rd party system that can do it only runs Windows 10 and Mac OS. I'm more familiar with Windows but if installing Mac OS is more easy then I'll switch. I'm using Linux (beta) to run virtual box, on Acer Chromebook spin 11 with Windows 10.


How can one save a file as plain text in TextEdit?

I'm not seeing an option to choose plain text encoding (.TXT extension) when saving a file in TextEdit.app in macOS. My documents seem to all be rtf - rich text format.  How can I change this?


Showing that $\mathbb{R}$ and $\mathbb{R}\backslash\mathbb{Q}$ are equinumerous using Cantor-Bernstein

I need to prove that $\mathbb{R}\backslash\mathbb{Q} \sim \mathbb{R} $  Using Cantor-Bernstein, need to show an injection from $\mathbb{R}\backslash\mathbb{Q}$ to $\mathbb{R}$ and from $\mathbb{R}$ to $\mathbb{R}\backslash\mathbb{Q}$.    $\mathbb{R}\backslash\mathbb{Q}$ is a subset of $\mathbb{R}$ so only need to show injection from $\mathbb{R}$ to $\mathbb{R}\backslash\mathbb{Q}$ to complete the proof.    Possible injection: $f:\mathbb{R}\to \mathbb{R}\backslash\mathbb{Q}$ defined as $f(x) = \pi x$ if $x$ is not a multiple of $\pi$; otherwise $f(x) = \sqrt{2} x$.    Not sure if $f$ actually is an injection...


How to prove that $$\lim_{x\rightarrow 0 }\frac{\sin\big(\tan(x)\big)- \tan\big(\sin(x)\big)}{\arcsin\big(\arctan(x)\big)-\arctan\big(\arcsin(x)\big) } = 1$$ First terms in Taylor expansion of the numerator and denominator is $-\frac{x^7}{30}$. So the direct proof is not beautiful and hard.


Right place to ask a "discussion" question (I'm setting up a blog, what should....)

I'm pretty sure this isn't the right place to ask this. I'm not aware of a stack site out there where this question would fit. If someone could point me to the right place it would be awesome.     The question I was going to ask is:       I am incorporating a blogging feature into my car enthusiast site. I want each user to be able to have their own blog and be able to browse other people's blogs. What blog engine would be best for this scenario?      I am using ASP MVC 4 and found  to look promising; however, I am a bit confused at the setup. This seems to be a blog set up for a personal site and not a "Nest of blogs" type of system. I've never done a blog before so I'm fresh meat here.


C++ Implement MVC error: 'View' does not name a type

I'm trying to implement MVC pattern in C++. I follow the instructions in the file:    But when I compile program I gets this errors:  In file included from C:\Users\Lukasz\ClionProjects\CDDB\Controller.h:10:0,                  from C:\Users\Lukasz\ClionProjects\CDDB\Controller.cpp:5: C:\Users\Lukasz\ClionProjects\CDDB\View.h:17:5: error: 'Controller' does not name a type      Controller *myController;      ^ C:\Users\Lukasz\ClionProjects\CDDB\View.h:28:13: error: 'Controller' does not name a type      virtual Controller *makeController() {}              ^ C:\Users\Lukasz\ClionProjects\CDDB\View.h:33:5: error: 'Controller' does not name a type      Controller *getController() { return myController; }      ^ C:\Users\Lukasz\ClionProjects\CDDB\View.h: In constructor 'View::View(Model*)': C:\Users\Lukasz\ClionProjects\CDDB\View.h:19:34: error: class 'View' does not have any field named 'myController'      View(Model *m) : myModel(m), myController(0)                                   ^ In file included from C:\Users\Lukasz\ClionProjects\CDDB\View.h:10:0,                  from C:\Users\Lukasz\ClionProjects\CDDB\View.cpp:5: C:\Users\Lukasz\ClionProjects\CDDB\Controller.h:17:22: error: expected ')' before '*' token      Controller( View *v )  : myView(v){                       ^ C:\Users\Lukasz\ClionProjects\CDDB\Controller.h:27:5: error: 'View' does not name a type      View    *myView;      ^   My files:  View.h  #ifndef CDDB_VIEW_H #define CDDB_VIEW_H   #include "Observer.h" #include "Model.h" #include "Controller.h"  class View : public Observer {   public:     Model *myModel;     Controller *myController;      View(Model *m) : myModel(m), myController(0)     {         myModel->attach(this);     }     virtual ~View() {  }     virtual void update() { }      virtual void initialize() {}      virtual Controller *makeController() {}      virtual void draw();      Model *getModel() { return myModel; }     Controller *getController() { return myController; }  };  class BarChartView : public View {  public:     BarChartView(Model *m) : View(m) { }     virtual void draw(); };  #endif //CDDB_CONTROLLER_H   Model.h  #ifndef CDDB_MODEL_H #define CDDB_MODEL_H  #include <iostream> #include <cstdlib> #include <list> #include <set> #include <iterator> #include "Observer.h"  using namespace std;  class Model{      string cdName;  public:     Model(string cdName);      void addRecord();     void removeRecord();     void attach(Observer *s) { registry.insert(s); }     void detach(Observer *s) { registry.erase(s); }  protected:     virtual void notify();  private:     set<Observer*> registry; };  #endif //CDDB_CONTROLLER_H   Controller.h  #ifndef CDDB_CONTROLLER_H #define CDDB_CONTROLLER_H   #include "Observer.h" #include "View.h"  class Controller : public Observer {  public:     virtual void handleEvent() {}      Controller( View *v )  : myView(v){         myModel = myView->getModel();         myModel->attach(this);     }      virtual ~Controller() { }     virtual void update() { }  protected:     Model   *myModel;     View    *myView;  };   #endif //CDDB_CONTROLLER_H   Model.cpp, View.cpp, Controller.cpp are empty. I compile this code using cmake  cmake_minimum_required(VERSION 3.3) project(CDDB)  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")  set(SOURCE_FILES main.cpp Model.h Observer.h View.h controller.h Controller.cpp Controller.h Model.cpp View.cpp Observer.cpp) add_executable(CDDB ${SOURCE_FILES})   Any ideas?   EDIT:  Ok, I add class Model; class View; into Controller.h but I have new error 25: error: invalid use of incomplete type 'class View' myModel = myView->getModel();


Are those sentences both negative or the first one is positive and second one is negative?

For he through Sin's long labyrinth had run, Nor made atonement when he did amiss...  Does these sentences mean that he did not run from commiting sins nor  made atonement when he did amiss or Does it means that he did run from commiting sins but did not made atonement when he did amiss? Thank you.


Can somebody help me solve this. I need to find the equivalent resistance of these resistors. I really don't know where the trick here is. If somebody could help me I would really appreciate it


I'm getting stuck in an infinite loop trying to compare a float to zero

I'm writing what should be a simple programme for an assignment that finds the ideal change to dispense, measured in the number of coins. My solution is to use a a while loop that keeps checking through coins and subtracting them from the customer change until change equals 0. However, I am getting stuck in an infinite loop and am completely stumped as to why.  Here is my code:  while (change > 0.0) {      for (int i = 0; i < numberOfCoins; i++) {          if ((change - coins[i]) >= 0.0) {             change = change - coins[i];             coinsTally[i] = coinsTally[i] + 1;             break;         }     } }   change is any value from 0.0 to 0.99, numberOfCoins = 6,   and coins[numberOfCoins] = { 0.5, 0.2, 0.1, 0.05, 0.02, 0.01}


after update SELF_REFERENCE_FROM_TRIGGER recursive save

I'm new to salesforce (apex - trigger) development and I'm currently reading through the manual and other threads on here on how to do this stuff, but I wanted to put this out here in case it was a simple fix someone would notice right away.  If not, maybe some leads or pointers would even help.  This is code I'm picking up from another developer.  trigger updateAllOpportunities on Opportunity (after insert, after update, after delete) {    List<Opportunity>   triggerOpps = Trigger.isDelete ? Trigger.old : Trigger.new;   for (Opportunity triggerOpp : triggerOpps) {     if (triggerOpp.Parent_Opp__c != null) {        // Add this Site Opp's properties to DOPP's site configuration.        List<Opportunity> opps = [Select Id, Name,             (select Id,                  Name,                  NumberofPositions__c,                  Account.Name  from Opportunities__r)                from Opportunity where Id = :triggerOpp.Parent_Opp__c];         Opportunity dopp = opps.get(0);        List<Opportunity> sopps = dopp.Opportunities__r;        Decimal totalPositions = 0;         for (Opportunity sopp : sopps) {             totalPositions += sopp.NumberofPositions__c == null ? 0 : sopp.NumberofPositions__c;        }             dopp.NumberofPositions__c = totalPositions;          update dopp;     }   } }


Is there a geometrical method to prove $x<\frac{\sin x +\tan x}{2}$?

Suppose $x \in (0,\frac{\pi}{2})$ and we want to prove $$x<\frac{\sin x +\tan x}{2}$$I tried to prove it by taking $f(x)=\sin x+ \tan x -2x$ and show $f(x) >0 ,when\space  x \in (0,\frac{\pi}{2})$ take f'$$f'=\cos x +1+\tan ^2 x-2\\=\tan^2 x-(1-\cos x)\\=\tan ^2 x-2sin^2(\frac x2)$$ I get stuck here ,because the last line need to be proved $\tan ^2 x>2sin^2(\frac x2) ,when\space  x \in (0,\frac{\pi}{2})$ $\bf{Question}:$ Is there a geometrical method to prove the first inequality ? (or other idea)  Thanks in advance.    $\bf{Remark}: $I can see the function is increasing $when\space  x \in (0,\frac{\pi}{2})$ like below :


I would like to force the listings package to be more selective when highlighting keywords. I'm currently including C source files in my document, and while I'm happy that occurrences of the float keyword are properly highlighted, I'd like the following line to appear as  #include <float.h>  instead of the current  #include <float.h>  In a similar spirit, else is fine, but #else should be typeset instead of #else.  I tried solutions like using deletekeywords={float.}, but to no avail (unsurprisingly, according to the documentation: "(...) by default some characters are not allowed inside keywords, for example ‘-’, ‘:’, ‘.’, and so on. (...)"). Playing with deletedirectives led nowhere either.


i have this code and it seems its vulnerable to sql injection. How can i secure this?   mysql_query $query = mysql_query("SELECT * FROM users WHERE username='$username'") or die (mysql_error());   $username = $_POST['username'];


Getting jQuery tablesorter to work with hidden/grouped table rows

I have the classical table with expandable and collapsible records that if expanded show several subrecords (as new records in the same parent table, not some child div/child table). I am also using tablesorter and absolutely love it.  The problem is that tablesorter isn't keeping expanded child records next to the parent records. It sorts them as if they were top level. So each time the table gets sorted by a column the child rows end up all over the place and not where I want them.  Does anyone know of a good extension to tablesorter or specific configuration that enables tablesorter to keep child rows grouped together with the parent row even after sorting? Or do I have to give up tablesorter in favor of some other API or start the ugly process of writing my own widget? Should I avoid the css-based approach of hiding individual rows of the table to represent collapse rows?


In the USER_TAB_PARITIONS, there is the attribute HIGH_VALUE, formatted TIMESTAMP' 2017-01-01 00:00:00'.  My problem: I want to convert HIGH_VALUE into a date with a simple query (without procedure, and HIGH_VALUE is as long stored).  So far I could transform it with that procedure:  set serveroutput on size 30000; DECLARE    CURSOR c1 IS    SELECT HIGH_VALUE, PARTITION_NAME    FROM USER_TAB_PARTITIONS    WHERE TABLE_NAME = 'MY_TABLE';     partition_date   VARCHAR2(100);    partition_name   VARCHAR2(1000);    date_val         DATE;    name_val         VARCHAR2(100); BEGIN    FOR c1rec IN c1 LOOP       partition_date := 'SELECT ' || c1rec.HIGH_VALUE || ' FROM DUAL';       partition_name := 'SELECT ' || c1rec.PARTITION_NAME || ' FROM DUAL';       EXECUTE IMMEDIATE partition_date INTO date_val;       DBMS_OUTPUT.PUT_LINE(date_val);       DBMS_OUTPUT.PUT_LINE(c1rec.PARTITION_NAME);    END LOOP; END; /   My question: Is there any possibility to do it without a procedure? For example like:  SELECT HIGH_VALUE, PARTITION_NAME FROM USER_TAB_PARTITIONS WHERE 1=1   AND TABLE_NAME = 'MY_TABLE'   AND HIGH_VALUE < sysdate-1;


Data recovery from an accidental format on ext4 partition

When I was installing Mint Debian edition unlike the classic edition, the installation automatically formated my home partition when I did not specify to format.  So the formatting previously was ext4 as is now. I believe the data is still there as it was a quick format.   I have now booted the computer up on a live USB to prevent writing on it.  Ran testDisk. Is there anyway to recover to a previous superblock so i can recover my data?


Is my heat pump's condenser fan motor bad?

The other day my AC stopped working. I'm thinking the condenser fan motor has gone bad (unit is ~10 years old). Here is what I did to troubleshoot which led me to believe it was the fan motor.  1.Turned on, sounds like the compressor kicks on, but the fan doesn't turn on.   I turned the power off and took the top grate off. The fan blades turn just fine. I took the side panel off and all the wiring looks good. I disconnected the fan from the defrost circuit and tested continuity on the two terminals on the defrost circuit (while thermostat was set to cool, temp was way down, but power was still off). Had continuity. I bypassed the defrost circuit by hooking the two wires together and turned power on. Compressor turns on, fan does not. I checked the contactor to make sure no wires were loose and look for corrosion. Everything looked good. In fact, with thermostat set to cool and temp turned down (high voltage power off), the contactor's electromagnet was working and the switch was on.   Basically I followed the instructions , which incidentally, the unit they are working on is identical to my unit, which was nice. The only thing I didn't check was the capacitor as I don't have a multimeter which checks farads.  I'm going to check the capacitor tonight as I'm borrowing a better multimeter from a friend. Assuming that checks out, does my diagnosis sound good?  Do I need to change the capacitor too?  Being a ~10 year old unit, I'm aware that I'll probably need to replace the whole thing soon. I'm hoping a new fan motor will buy me a few years though. If not, I'd rather waste $100 instead of $200 trying to replace the motor.  Update Based on the info in , I decided to fire up the AC and give the fan a push. It started right up. I got my friend's multimeter, but it only went up to 20μF. My capacitor said 40μF, so I didn't test it. Since spinning the fan blades with the AC on got it going, I'm going to replace the capacitor today.


Whenever I read a nice question, I used to mark it as a favorite question. Today, while I was looking at my profile's favorite section, it was as follows:    Why does my favorite count vary on my profile? Is it a bug, or am I missing something with respect to the favorite section of my profile? I marked the areas causing confusion with circle in the picture.  Kindly clarify


I'd like to know how to export html content to ms word.  Here is my code.  header("Content-type: application/vnd.ms-word"); header("Content-Disposition: attachment;Filename=document_name.doc");  echo ""; echo "<meta http-equiv=\"Content-Type\" content=\"text/html; charset=Windows-1252\">"; echo ""; echo "My first document"; echo ""; echo "";   Succeed to export msword file but how could I use css code like border-radius?  I used style='border-radius:50%' but it is not working.  Anyhelp would be appreciate.   I'd like to know how to do style work of that doc file.


How to prove that the set of natural numbers $\mathbb{N}$ has the same size as $\mathbb{N\times N}$?

How to prove that the set of natural numbers $\mathbb N$ has the same size as $\mathbb N \times \mathbb N$?  Definition: We know that two sets have the same size when there is an injection from one set to the other and the other way round.  I was thinking of the following proof:  $f: \mathbb N \to  \mathbb N \times \mathbb N; f(n)=(n,1)$  we have that $f$ is an injective function because if we chose $j$ and $t$ in $\mathbb N$, then we will have $fj=j=t=ft$, hence the function is injective.  and we can take: $g: \mathbb N \times \mathbb N \to \mathbb N ; f(n,1)=n+1$  we have that $g$ is an injective function because if we chose $h$ and $k$ in $\mathbb N \times \mathbb N $, then we will have $fh=h=k=kt$, hence the function is injective.  Hence because of the definition above we conclude that the two sets have the same size.


Is there a theoretical-physics masters program that accepts mathematics graduates?

I plan to graduate with an honours (four year) degree in philosophy and a general (three year) degree in mathematics. Are there any physics graduate programs that might accept me if I were to apply?  For context: My plan-A is to work in academic philosophy. A physics education might not appear on the resume of most philosophy professors, but I suspect that knowing about physics could improve a philosopher's thinking about a number of questions. Accordingly, it seems worthwhile to study physics during either, a one or two year detour, several years of concurrent distance education, or the summer terms of my philosophy education. Self-study is an option, but I'd prefer to earn a credential in order to improve my future applications to graduate schools and to employers.


I am working on a dataset that has a dependent variable that is binary, but it contains 98% of 0's and 2% of 1's. I am trying to use Logistic regression to predict purchase of a product. But because of the huge number of 0's, the model is not predicting well and getting a large number of false positive result.  Kindly suggest how can I approach this.


Pre-generate Review audits to avoid the lag?

When reviewing on Suggested Edits:   Normal suggested edits are displayed instantly. Review audits take 2 seconds to load (and that's not because of my ISP).   So whenever I see the loading animation and have to wait a bit, I know before even looking at the changes that I can immediately reject the suggested edit.  Now, to quote  ():     There are many ways to identify audits (e.g. click to see the post itself, the user, the vote count, etc.). Almost all of these ways involve having to further investigate the post. By this time, you've already carefully reviewed the post, which is the intent of the queues.   This let us understand that the 2 seconds lag is breaking the game: it allows detection of the audit without careful review of the post, without further investigation.  My feature-request is to have Review audits being served as fast as real suggested edits. To achieve that, you could maybe pre-generate audits?


If $ \ \ \large \sum_{n=0}^{\infty} \frac{1}{n+1} \binom{2n}{n} x^n= \frac{1-\sqrt{1-4x}}{2x} \ $ , then show that $ \ \sum_{n=0}^{\infty} \binom{2n}{n}x^n = \frac{1}{\sqrt{1-4x}} \ $ .   Answer:  I have no idea  how to start this type of  .   Any idea ?


If a character with the shillelagh spell and polearm master feat can they use a d8 for their second attack with a quarterstaff?  Shillelagh For the duration thereafter, you can use your spellcasting ability modifier instead of Strength for the weapon, and its damage die becomes a d8.    Polearm Master When you take the Attack action and attack with only a glaive, halberd, quarterstaff or spear, [...] the weapon's damage die for this attack is a d4, and the attack deals bludgeoning damage.  One could argue that the feat makes it clear that your extra attack with Polearm master says that it deals a d4, period. But one could also say that the d4 is one of the quarterstaff's damage dice, and therefore becomes a d8 because you are making a second attack with the weapon.


Reference Text that develops Linear Algebra with Knowledge of Abstract Algebra

Background: Due to some unfortunate sequencing, I have developed my abstract algebra skills before most of my linear algebra skills. I've worked through Topics in Algebra by Herstein and generally liked his approach to vector spaces and modules. Besides a very elementary course in linear algebra (where most of the time went towards matrix multiplication), I have not developed any other linear algebra skills.  But it seems that it is now necessary for me to do so. Most of the topics that I am looking at now require some background of linear algebra and I still lack understanding of ideas like: bilinear forms, invariant subspaces, eigenvalues, requirements for diagonalization of a matrix and so forth.  This brings me to my question (provided there are any)     Question: What are some good texts that develop the theory of linear algebra from a perspective of general algebra?   Are there any texts that develop the key (elementary) ideas of linear algebra in an abstract setting? Thank you for the help!


Dot product between momentum and position $ \langle p|x \rangle$

I've been trying to derive the result of the following dot product in position space: $\langle p|x\rangle$. The information I'm supposed to be using: i) Any state can be written as a linear combination of the basis vectors: $|p\rangle=\sum_i a_i|i\rangle$ ii) The dot product between two functions is given by: $\langle f|g\rangle=\int_{-\infty}^{\infty}f(x)^*g(x)dx$ iii) The eigenstates of the operator $\hat{x}$ are $|x\rangle$. iv) I must use the eigenstates of p and x: $\langle p|x\rangle =\int_{-\infty}^{\infty}\psi^*_p(x)\psi_x(x)dx$ v) The representation of the momentum operator is $\hat{p}=-i\hbar\frac{\partial}{\partial x}$ vi) Functions can be represented as $\psi(x)=\langle x|\psi\rangle$. Well, I'm pretty much struggling to start to solve this problem and it seems that my lack of understanding regarding the representation of an eigenstate in a base might have to do with it. What I thought first was: Using (iv) and (vi) I got $\langle p|x \rangle =\int_{-\infty}^{\infty}\langle \psi_p|x\rangle ^*\langle x'|\psi\rangle dx{} dx'$ , where $|x\rangle \langle x'|$ should be an operator. However, I'm stuck from this point forward. I don't know how to write the eigenstates in a way that helps my attempt. What is wrong with my approach?


Prove that $\mathbb{Q}(\sqrt{(2+\sqrt{2})(3+\sqrt{3})})$ is Galois over $\mathbb{Q}$ is Galois and determine the Galois group

I aim to prove that $\mathbb{Q}(\sqrt{(2+\sqrt{2})(3+\sqrt{3})})$ is Galois over $\Bbb Q$. To do this, I aim to show that it is the splitting field of the minimal polynomial of $\mathbb{Q}(\sqrt{(2+\sqrt{2})(3+\sqrt{3})})$.  Thee minimal polynomial is $144-288 x^2+144 x^4-24 x^6+x^8$. And all its roots are:$\pm \sqrt{(2\pm \sqrt{2})(3\pm \sqrt{3})}$  I do  notice this post:   But I cannot fully understand how I can do that. My questions are:   Call $\sqrt{(2+ \sqrt{2})(3+ \sqrt{3})}=\alpha$. How can we show that $\pm \sqrt{(2\pm \sqrt{2})(3\pm \sqrt{3})}\in\Bbb Q(\alpha)$? There is a comment which mentioned a trick to check if we have found all the roots.     Part 3 is not tedious at all, just apply the automorphism $\sqrt{2}\rightarrow -\sqrt{2}$ to the polynomial evaluated at $α$ to see that it remains zero. Repeat for $\sqrt{3}$.    I would like to learn about the trick mentioned in the comment but I cannot fully understand it. S ocould someone please show me how to do that?  And now I need to determine the Galois group of $\Bbb Q$. Is there any rather simple way to see what the Galois group is?   Thanks for any help!  EDIT: Now I had stucked on it for some time and I think I do need help...  We know that the automorphism is uniquely determined by where it sent the generater to. So we only need to determine its effect on $\mathbb{Q}(\sqrt{(2+\sqrt{2})(3+\sqrt{3})})$.   As $(\sigma(\mathbb{Q}(\sqrt{(2+\sqrt{2})(3+\sqrt{3})})))^2=\sigma((\mathbb{Q}(\sqrt{(2+\sqrt{2})(3+\sqrt{3})}))^2)=\sigma(\mathbb{Q}((2+\sqrt{2})(3+\sqrt{3})))=6+2\sigma(\sqrt{3})+3\sigma(\sqrt{2})+\sigma(\sqrt{6})$. I need to determine where to send $\sqrt{2},\sqrt{3},\sqrt{6}$.   But I only know that I can send $\sqrt{2}\mapsto\pm\sqrt{2}$, same to $\sqrt{3},\sqrt{6}$. But there are then too many possiblities. So what should I do now to rule out some possiblities?  Now I realize that maybe I need not determine where to send $\sqrt{6}$ to because once we determine $\sqrt{2},\sqrt{3}$ we have already know that where to send $\sqrt{6}$...  Is that correct?


"java.lang.NullPointerException" when splitting the string

I am not so expert in java as i am learning .I am facing that error at :  charArrays = s.toCharArray(); I don't know the reasons. Though i have made array size too big but still unclear.  I have added another function which is sending to crossover   .....             public void chr_intval(){             int[] array = new int[100] ;             float[]af = new float[6];              String [] gf =new String[7]; // for generating generation therefore copying              Random randomGenerator = new Random();             System.out.println("Chromosome     Genes    Integer value       f(x)               f'(x)    Fitness ratio");              for(int i=1,j=1 ; i<=6; i++,j++){                 array[i] = randomGenerator.nextInt(100); // generate random 6 integers from 1<x<100                 float[] ar2 = new float[array.length];                 ar2[i]= (float)array[i];                 System.out.println("C"+j+   "            "+Genes(array[i])+"   "+array[i]+"              "+f_x(ar2[i])+"            "+fitness_function(f_x(array[i]))+"    ");//+fit_ratio(fitness_function(f_x(array[i])))); // print c1, c2,....                  af = new float[array.length];             //  gf= new String[array.length];                 af[i]= fitness_function(f_x(array[i]));                 gf[i]= Genes(array[i]);      // send to cross_over       //          System.out.println(fit_ratio(af));              }     //      System.out.print("gf"+gf[2]);             Cross_over(gf,af);         }        public void Cross_over(String[] gf, float[] af) {     // System.out.print("gf"+gf[3]); all values are coming successfully      char[] charArrays = new char[1000];      Character[] characterArray = new Character[charArrays.length];      int i = 0;      for(int j = 0; j < af.length; j++) { // comparing fit-funct         if(af[j] > af[0]){             af[0]= af[j];         }     }     if(af[0] >= 95) {         System.out.println("candidate's fitness "+af[0]);     }     else{  // start cross-over by tokenizing  the array         // charArrays[] = gf.toCharArray();          for (String s : gf) {             charArrays = s.toCharArray(); // <--- Error here         }     }     for(int y = 0; y < 8; y++) {         System.out.print( characterArray[y] );     } }


I have a very basic doubt in Java.  Here is a code I have written. From a method in class A in package A, I try to instantiate an object of class b of a different package and call its method, to which I pass a list.   parseObjectList = new ArrayList<ParseObject>();  pullAllService.pullAllData(queryType,parseObjectList);   and in the function I do some manipulation:   public void pullAllData(String queryType,List<ParseObject> parseObjectList) {     ParseQuery<ParseObject> query = null;      List<ParseObject> parseObjects = parseObjectList;      if(queryType.equals("a"))     {         query = new ParseQuery<ParseObject>("a");     }     else if(queryType.equals("b"))     {         query = new ParseQuery<ParseObject>("b");     }        try {         parseObjects = query.find(); //I get the list         /* final List<ParseObject> finalParseObjectList = parseObjectList;         curActivity.runOnUiThread(new Runnable() {             public void run() {                 ToastMessageHelper.displayLongToast(curActivity, "Objects found : ");                 for (int i = 0; i < finalParseObjectList.size(); i++) {                     ToastMessageHelper.displayLongToast(curActivity, finalParseObjectList.get(i).get("Name").toString());                     System.out.println();                 }             }         });     */      } catch (ParseException e) {     e.printStackTrace();     }     catch(Exception e)     {         e.printStackTrace();     }   }   after which if I try to print the list in class A's method. I get an empty list.  But if I do this,   parseObjectList = new ArrayList<ParseObject>();  parseObjectList = pullAllService.pullAllData(queryType,parseObjectList);   and make it return the list from pullAllData() (by changing the return type and returning the list) , I get the list with the expected data.  I thought that just by passing the parseObjectList into the function, the passed parameter would behave as a reference and automatically be assigned the intended data. What's wrong here?


I've got some problems with my xbox one controller. My ubuntu does recognize that I have plugged in a xbox controller (lsusb and jstest show me the xbox controller) but it ignores every input and the xbox symbol on my controller stays dark. Now I do not have a clue what i should try next, is there anything I have to do so that my os will accept inputs from my controller? Did I miss some article about that problem or is it working fine for everyone than me?


I'm trying to apply a LARGE function to get the 5 largest values from a column ignoring duplicates. I did some searching around and found some proposed solutions but they don't seem to work for me. In my actual application the range is found by an array formula so I'm not sure if non array formulas will work here. My original function was {=LARGE(IF($A:$A=$A2,$B:$B),2)} dragged down the column. Replace 2 with 3 for the third largest, 4 for the fourth largest, etc. This worked except in the case of duplicates.  For example:  The data is in column 1 and the desired output is in column 2:  1    5  2    4 2    3 3    2  3    1 3 4 4 5   Things I have tried:   {=LARGE(IF(A:A < LARGE(A:A,i-1),A:A),1)} for the i-th largest value.    -Inputting this gives 3 for both i = 3 and i = 4. =LARGE(A:A,COUNTIF(A:A,MAX(A:A))+1)   -This doesn't seem to be any different than just LARGE(A:A,2) {=MAX(IF(A:A < LOOKUP(9.99999999999999E+307,A:A),A:A))}  -This does retrieve the value 4 but I'm not sure how to generalize it to the kth largest value.    VBA solutions are fine as well. I tried to code one myself but wasn't sure how to code in the array formula IF($A:$A=$A2,$B:$B).


Pairwise Independence of Events in Rosenthal

$\exists$ this exercise in Rosenthal's :    For letters d and e, how do you show that the ff events are pairwise independent?    My attempt:  It suffices to show that $B_n$ and $B_{n+1}$ are pairwise independent (because Borel-Cantelli 2 can use pairwise independence). To do this, it suffices to show that the index of the last event in $B_n$ is less than the index of the first event of $B_{n+1}$, that is, $\left \lfloor n\log_2 n^2 \right \rfloor + \left \lfloor \log_2(\left \lfloor n\log_2n^2 \right \rfloor) \right \rfloor \leq \left \lfloor (n+1)\log_2 (n+1)^2 \right \rfloor + 1$.  How to show this? I tried using $\left \lfloor k \right \rfloor \leq k$, but I'm not sure that that does anything...  LHS $\leq \left \lfloor (n+1)\log_2 (n+1)^2 \right \rfloor  +  \left \lfloor \log_2(\left \lfloor n\log_2n^2 \right \rfloor) \right \rfloor $ < $\left \lfloor (n+1)\log_2 (n+1)^2 \right \rfloor + 1$ because...ugh...  $\left \lfloor \log_2(\left \lfloor n\log_2n^2 \right \rfloor) \right \rfloor \leq \log_2(\left \lfloor n\log_2n^2 \right \rfloor) < 1$?  I don't think the last inequality is true.  Help please?


Where is apache web root directory on Ubuntu?

On Ubuntu Trusty, which is the apache root directory for web pages?


Could Voldemort have ended the protection from Harry’s mother by killing the Dursleys?

Dumbledore explains to Harry in Order of the Phoenix that he is protected so long as he returns once a year to the Dursleys’ home:     While you can still call home the place where your mother's blood dwells, there you cannot be touched or harmed by Voldemort. He shed her blood, but it lives on in you and her sister. Her blood became your refuge. You need return there only once a year, but as long as you can still call it home, there he cannot hurt you.   If Voldemort, or one of his Death Eaters, had killed the Dursleys (perhaps while Harry was away from Hogwarts), then Privet Drive would not be “the place where your mother’s blood dwells”. There are no other relatives of his mother that he could stay with, which would mean that nowhere else would qualify for that magic.   Wouldn’t that mean that the following year, Harry would have nowhere to go and the protection would not renew, thus he would be vulnerable to Voldemort?


How to create a portal to the End in Creative? (Mine craft)

I have tried to make an End portal, I have tried-   Placing all in different angles Creating a 3x3 box