Need book ID help - long distance travel by cloning

I'm trying to find the name of a book I read awhile ago. It involved a bunch of gateways that you could sort of fax yourself to. You could have multiple copies of yourself running around and if one of them died they could be recreated from the last time they went through the portal. The story is about someone going around and killing all the copies of this guy, I also remember a part where he found copies of himself and of his attempted murderer that that guy had tortured almost beyond recognition.   Anyone know this book?


Angular momentum squared and Hamiltonian?

I'm trying to show, for the Hamiltonian $H = \vec{P}^2/2m + V(\vec{X})$, that $[\vec{L}^2,H]=0$ if $V(\vec{X}) = V(|\vec{X}|)$, and I pretty much almost have it, there's just one thing I'm getting messed up on.  So what I did was: $$ [\vec{L}^2,H] = [L_x^2 + L_y^2 + L_z^2, \frac{\vec{P}^2}{2m} + V(\vec{X})] = [L_x^2 + L_y^2 + L_z^2, \frac{\vec{P}^2}{2m} + V(|\vec{X}|) ] $$ $$ = [L_x^2,\frac{\vec{P}^2}{2m} + V(|\vec{X}|)] + [L_y^2,\frac{\vec{P}^2}{2m} + V(|\vec{X}|)] + [L_z^2,\frac{\vec{P}^2}{2m} + V(|\vec{X}|)] $$ Looking at the $L_x^2$ component: $$ \rightarrow [L_x^2,\frac{\vec{P}^2}{2m} + V(|\vec{X}|)] = \frac{1}{2m}[L_x^2,P^2] + [L_x^2,V(|\vec{X}|)] $$  $$ = \frac{1}{2m}[L_x^2,P_x^2+P_y^2+P_z^2] + [L_x^2,V(|\vec{X}|)] $$  $$ = \frac{1}{2m} \bigg( [L_x^2,P_x^2]+[L_x^2,P_y^2]+[L_x^2,P_z^2] \bigg) + [L_x^2,V(|\vec{X}|)] $$  Now for the momentum parts, that's a lot of tedious work that I won't type up, but at the end of the day, I get that $$ [L_x^2,P_x^2]=[L_x^2,P_y^2]=[L_x^2,P_z^2]=0 $$ and similarly for $[L_y^2,P^2]=0$ and $[L_z^2,P^2]=0$. My problem is this, for this to work out, I need $$ [L_x^2,V(|\vec{X}|)] = 0 $$ and similarly $$ [L_y^2,V(|\vec{X}|)]=[L_z^2,V(|\vec{X}|)]=0 $$ but I don't really understand why that would be the case? Any insight would be appreciated.


Prove that $\sum_{n=1}^{\infty} \big(\frac{1}{4}\big)^n {2n \choose n}$ diverges

I need to prove that the following series $$ \sum_{n=1}^{\infty} \bigg(\frac{1}{4}\bigg)^n {2n \choose n}$$ diverges.  I've managed to change it to the following formula: $$ 4^n=(1+1)^{2n}=\bigg(\sum_{k=0}^n{n\choose k}\bigg)^2 \text{ and } {2n\choose n}=\sum_{k=0}^n{n\choose k}^2 \text{ so }$$ $$\sum_{n=1}^\infty \bigg(\frac{1}{4}\bigg)^n {2n \choose n} =\sum_{n=1}^\infty \frac{\sum_{k=0}^n{n\choose k}^2}{\left(\sum_{k=0}^n{n\choose k}\right)^2}   $$ Where do I go from here? I know that the limit of series' sequence goes to $0$ but that isn't helpful really since I need to prove that it diverges.  Also all the ratio tests and root test are inconclusive. I already checked that. Think of 4 as variable $a$. I need to check for which $a$ this series converges. I already know that for $a>4$ it does, but I need to prove that for $a=4$ it diverges. There was a mistake in my calculating of limit in Raabe's test which concluded that this series is indeed divergent.


Is there a difference between "seemingly" and "apparently"

In the context of a business report would there be a difference (albeit subtle) between writing of "a seemingly unambitious plan" and "an apparently unambitious plan"?  To me the first seems to suggest that in reality the plan is ambitious, we just can't see it. Is this also the case for the second?  Edit — more explanation:  One of my difficulties is the differences in definitions (seemingly doesn't appear in most dictionaries).  The definitions from Google:     seem:         Give the impression or sensation of being something or having a particular quality: "Dawn seemed annoyed".         apparent:         Clearly visible or understood; obvious.   Seeming real or true, but not necessarily so.       Definition from Merriam-Webster:     seeming:   outwardly or superficially evident but not true or real    So the MW definition of seeming seems to closer to the definition of apparent in Google to me.  My query really is whether and to what extent does either word imply that the reality is or may be different to the appearance.


In the UK there are 90 bingo balls. A bingo card consists of 9 columns and 3 rows. A row contains exactly five numbers and four blanks. A column consists of one, two or three numbers and never three blanks. The columns are occupied by the number chosen from 1-9 (only nine), 10-19 (ten), 20-29 ... 70-79 and importantly 80-90 (eleven). Numbers in columns are ordered from top to bottom.  How many possible unnumbered card layouts are there?  How many possible numbered cards are there?  I have started to approach this problem by first choosing the blanks for the first two rows and then attempting to work out a compensating row. This was hard.  Next I begun to understand that there were a number of equivalence classes as columns could be reordered for the purposes producing different layouts.  Next I looked into the most convoluted card which had five numbers followed by four blanks in the first row and four blanks followed five number in the second. This satisfied the "no blank column" requirement. Now the final row could be arranged however it wanted, though there was one confusing overlap to deal with.   I considered another convoluted card which had as many columns of three as possible. It turns out it's possible have a maximum of three columns of three which also gives rise to the maximum of six columns of one. It also turns out you can have a maximum of six columns of two. I think the starting point might be to determine the classes of card initially by column combinations and then permute them.  Having gotten all muddled by the layouts, I turned to the numbers. With a single number, it was one of 9, 10 or 11 depending on the column and that was easy. For the two number case, let's say with a column of ten, the first ($i$) was chosen from 9 and the next from $10-i$. It suddenly occurred to me that it was just combinations, phew. How to fit that with the whole business of column choice lost me.  It seems possible that for each possible "set" of columns, there will be a way of determining the distribution of possible first columns and adding in an appropriate factor for the number combinations.  Frankly, it's all getting bigger than my coffee table.   Any simplifications from higher maths I'm missing?


In English, we have many words ending in or containing “gh”, but in some cases, the two letters are silent, while in others, it is pronounced as “f” . We have the words tough, rough, and draught, which pronounce "gh" as an "f" sound, while the words height, weight, through, drought, and many others do not pronounce the sound at all. Are there any rules governing the pronunciations of these words? Or is the reason for this based in the origins of the words? Edit: My question focuses specifically on the “gh” combination, not the pronunciation of “ough”. In my examples I gave words such as the words height and weight which contain “eigh”, not just words with “ough”.


How to list the Hooks and order of execution in current loading page?

I need to know the list of hooks that are called in the current page . How to identify the priority assigned to the action and filters in the action . If i want to remove the default action on word-press . It cause any error ?  May i overwrite the default action that to be execute?   add_filter( $tag, $function_to_add, $priority, $accepted_args );    in this case i change the priority as 50 . i don't get any changes compare with 10 or Default. if This Priority value is for order of execution means i need to change the values as bigger or smaller?.


Trig integral $\int ( \cos{x} + \sin{x}\cos{x}) \, dx $

Assume we have:  $$ \int (\cos{x} + \sin{x}\cos{x}) \, dx$$  Two ways to do it:  Use $$\sin{x}\cos{x} = \frac{ \sin{2x} }{2} $$ Then $$ \int \left(\cos{x} + \frac{\sin{2x}}{2} \right) \, dx = \sin{x} - \frac{ \cos{2x} }{ 4 } + C. $$ The other way, just see that $ u = \sin(x), du = \cos(x)dx $, $$ \int ( \cos{x} + \sin{x}\cos{x}) \, dx = \sin{x} + \frac{\sin^2{x}}{2} + C. $$  Now the part I don't see fully is, why aren't these results completely equal?  Taking the 2nd result, \begin{align} \sin{x} + \frac{\sin^2{x}}{2} &= \sin{x} + \frac{1}{2} \, \left( \frac{1 - \cos{2x}}{2} \right) \\ &= \sin{x} + \frac{1}{4} - \frac{\cos{2x}}{4}. \end{align}  So you have to absorb $\frac{1}{4}$ into $C$ for them to be equal.  Shouldn't they be equal straight away?


Adjusting polygons to boundary and filling holes

Here's the problem:   Where:  1: department boundary  3: polygons inside department boundary that "touch" the department boundary(1). They are not necessary fitting well inside  2: holes between 1 and 3  I need to "adjust" polygon shapes (3) to "match" department boundary (1) filling the holes (2)    Using PostGIS:  My 1st approach was to get the st_pointonsurface of all numbers 2 and number 3 by departments. Then assign the holes (2) to the nearest polygon by pointonsurfaces between each other.  See image (from another department boundary but same problem, exceeding dotted lines with no fillcolor are polygons zones that exceeded department boundary that I've already cut off by department boundary so no problem there)    This worked but got me another problem::   some (lots of) holes (2) that where attached to the nearest polygon (by st_pointonsurface) were really long lines     Here (2) are the holes that were attached to the nearest polygon, and the result is 'strange' new polygons with really long lines.    I can use any of ArcGIS 10, Quantum GIS and PostGIS to solve this, but I can't get a way to solve this.    EDIT  How about using topology? what rules may be useful for this problem?    How topology will resolve when multiple polygons are fighting to get the same hole?    EDIT 2  Using geometry approach with PostGIS.  one idea: - make buffers of the multiple polygons that are inside the department boundary - get the st_intersection between buffered polygon vs original polygon + hole. This way the new "buffered" polygon only keep the buffer where the "hole"-intersected-area is touched.   This may work with simple examples .. but with real world holes and polygons.. This will leave us another problem: the overlaps between different buffered polygons inside hole areas..


Could it be that at the big bang equal amounts of matter and antimatter were created, but the antimatter got stuck in black holes?

I recently watched PBS spacetime's video series on the black hole information paradox. Where they first discussed the no hair conjecture and then later also the true destruction of information by Hawking radiation. This led me to wonder, if information is apparentely unavailable to the outside universe after it has entered a black hole, is it possible that at the big bang equal amounts of matter and antimatter were created, but, by chance, a greater amount of antimatter than matter fell into black holes, leaving slightly more matter than antimatter in the outside universe, most of which anihilated and a small portion makes up everything we can now see? If this were the case, the black holes of our current universe would contain equally as much antimatter as the rest of the universe contains matter, however, by the no hair conjecture we should not be able detect any difference between a electrically neutral black hole made of matter or antimatter.


In 2011, I went to Bournemouth to study English, but I overstayed for almost 4 months after my visa expired. It has been 5 years since I left the UK.  Now, I would like to apply for a visa, to visit a friend, but I'm afraid to risk a refusal. Will my overstay affect an application for a tourist visa?


$$\sum _{i=1}^n\left(-1\right)^{i+1}\:\binom{n}{i}\:\frac{1}{i}=1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{n}$$ Can someone give me a hint on how to give the proof, I am stuck when I am proving it for p(n+1):  $$1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{n}+\left(-1\right)^{n+2}\cdot \frac{1}{n+1}$$  is there a handy way to get rid of the $-1$?  $\sum \:_{i=1}^{n+1}\left(-1\right)^{i+1}\:\binom{n+1}{i}\:\frac{1}{i}=\sum \:_{i=1}^{n+1}\left(-1\right)^{i+1}\:\left[\binom{n}{i}+\binom{n}{i-1}\right] \frac{1}{i}=\sum \:\:_{i=1}^{n+1}\left(-1\right)^{i+1}\binom{n}{i}\frac{1}{i}+\binom{n+1}{i} \frac{1}{n}$


Real valued continuous functions in metric spaces

Assume that the metric space (X, d) is not compact. Show that there exist a real-valued function like f which is continuous but not bounded.


How to render parts of the camera view and merge afterwards?

I watched a video on youtube (I lost it) that shows rendering parts of the screen to combine them in a single image. I followed it to the point where I couldn't adjust the dimensions under the "set render border", but in the video he had dimensions and I have nothing.  I need it for 4K and 8K renders (without anti-aliasing), but my laptop can't handle it all at once and I don't have time for a 4 hour waiting so this feature will work perfectly.  I'm using version 2.76 so is it moved to another place or removed. Maybe a bug?


Example of non well-orderable set in ZF.

Definition: For a set $x$ define its cardinality by $|x|=\min\{\alpha\in On\mid\alpha \approx x\}$.   where $On$ is the calss of all ordinals, $\alpha\approx x$ means there is a bijection $f:\alpha\rightarrow x$.  In ZFC we can say that every set $x$ has a cardinality, because $x$ can be well ordered and thus is bijective to atleast one ordinal. Can we turn this around? That is, in ZF, can we construct (find) a set, that has no cardinality? That means $\{\alpha \in On\mid \alpha \approx x \}$ is empty, quivallently there is no well order on $x$.


My webcam just came on "out of the blue"

I have a Microsoft LifeCam HD sitting atop my monitor.  Today, completely out of the blue, its light came on -- I was simply browsing the web (in Chrome) when it happened.  After about 5 minutes the webcam turned off.  Naturally, I immediately suspected my ex-wife (when in doubt, I always suspect her), but she isn't computer savvy enough.  I looked over the process list and didn't see anything suspicious.  I am running a couple of open source projects and free apps (e.g., greenshot, powermenu, supertray), but I've had them for years.  Autoruns reports nothing suspicious in the startup and neither does Windows Defender.  Anyways, what could it be?  What should I look at next?


Output of aov() in R varies with changing order of independent variables

I need to understand why does the summary output of aov() in R vary when the order of independent variable changes. Like for example: summary(aov(y~A+B, data)) is different from summary(aov(y~B+A,data)).


Static class members causing linking error

Trying to make a static class where other objects can access the member methods like a singleton class C { public: C(){} ~C(){}      static int& instance()     {         if(!_pInt)         {             _pInt = std::move(std::make_unique<int>(5));         }         return *_pInt.get();     }       private:     static std::unique_ptr<int> _pInt; };   int main() {     std::cout<<C::instance()<<std::endl;   return 0; }  When building the code, the linker complains undefined reference to `C::_pInt'  I could not understand why the linker cannot find the definition of this member, can someone give me some hint? Thanks!


As per the , this FAQ will serve the following purposes:  To be the canonical reference for moderators across the Stack Exchange sites for things that are beyond question (typically, "how" questions) For situations that a moderator will face, provide information to help understand the nuances of that situation, so that the moderator can make best possible decision that is in the interest of their Stack Exchange site and Stack Exchange in general (typically, "when" questions) To bring new moderators on sites (pro tempore or elected) up to speed quicker.  Essential Reading       Tools             Post content                Voting to Close     Comment flags    Profile content     Abuse     Post notices    Chat       People      Miscellaneous


If I have an older PC laptop, that doesn't have 2g of harddrive space, which older version should I use?


Does python support multiprocessor/multicore programming?

What is the difference between multiprocessor programming and multicore programming? preferably show examples in python how to write a small program for multiprogramming & multicore programming


In this code I already coded counts as a dict beforehand. Here when I print my get_word_prob function, I get 0.0 as a result. When I print pneg, pword or others, I get name is not defined error. I guess my definition of these variables is not correct but could not find any other way to do so. It is probably easy but I am a total beginner.   def get_word_prob(counts, word, polarity):     """      calculates the probability of a word given a polarity       Parameters:     counts (dict): the dictionaries 'pos' and 'neg' which count word occurances     word (str): the word you want to get the probability for     polarity (str): wither 'pos' or 'neg'      Returns:     probability (float):  the probability of a word given a polarity       """     probability=float()     # Your code goes here     #P(word|polarity)=(p(polarity|word)*p(word))%p(polarity)     #P(word)=(counts[pos][word]+counts[neg][word])%counts[pos]+counts[neg]      for word in counts['pos']:          pword=float((counts['pos'][word]+counts['neg'][word])/sum(counts['pos'].values())+sum(counts['neg'].values()))     #p(pos)=counts[pos]%(counts[pos]+counts[neg])         ppos=float(sum(counts['pos'].values())/(sum(counts['pos'].values())+sum(counts['neg'].values())))         pneg=float(sum(counts['neg'].values())/(sum(counts['pos'].values())+sum(counts['neg'].values())))     #p(pos|word)=counts[pos][word]%(counts[pos][word]+counts[neg][word])         pposword=float(counts['pos'][word]/(counts['pos'][word]+counts['neg'][word]))     #p(neg|word)=counts[neg][word]%(counts[pos][word]+counts[neg][word])         pnegword=float(counts['neg'][word]/(counts['pos'][word]+counts['neg'][word]))         probability == float((pposword*pword)/ppos)     for word in counts['neg']:         probability == float((pnegword*pword)/pneg)                 return probability # P(word|polarity)   #Do not change #print(get_word_prob(counts, "great", "pos")) # should print 0.00255902660421998 #print(get_word_prob(counts, "glad", "neg")) # should print 0.00012164155275442091 #print(get_word_prob(counts, "wugs", "neg")) # should print 0 print(pneg)


So im not an python developer but was reading a source code of a python console app which i would like to write it in c# and experiment with it. But i couldn't understand this expression:  result = content[:4] + sig + content[19:]   Can someone explain me what is [:4] and [19:].


Is an academic probation for not finding a research advisor in time considered "disciplinary sanction"?

Is an academic probation for not finding a research advisor in time considered "disciplinary sanctions by any university"?  This is asked in a graduate school application.  Does "sanction" mean penalty?  Does "disciplinary" include the issue of finding a research advisor in time?  Thanks!


How to completely delete account from stackexchange network?

I know it has been asked other times but my problem is a little different: I want to completely delete my account from the stackexchange network (not just from a community) I tried deleting from stackexchange.com in the profile section but there is no option to delete it. What should I do?


Sous vide stopped heating water overnight, is it still safe to eat?

Started some beef short ribs yesterday morning at 185f for 24 hours, went to bed with about 11 hours left on the sous vide but when I woke up this morning the water was only at 133f according to the sousvide, and my other thermometer in the water read 127.5f. I put them in an ice water bath right away for about 20 minutes until they were cool and they're now in the fridge. Are these still safe to eat? I have no idea how long they've been in the water at under 130f, but it's probably 10L of water and it's wrapped in towels and had a lid on it to keep the heat in so I assume it took a long time to get down to that temp.


Evaluate the series $\sum _{n=1}^{\infty} \frac{n}{5^n}$

$$\sum _{n=1}^{\infty}\frac{n}{5^n}$$  I tried to plug in $n=1,2,3,4,...$ but I can't use common ratio to solve problem. I think there is another way like using differentiation or integral but I don't no exactly what to do.


Status of B1/B2 visa after citizenship change?

I have a valid B1/B2 visa valid to US till March 2019 on Indian passport, I changed my citizenship to Australian. Is my B1/B2 visa on Indian passport valid?


I am looking for either an online tool or one that I can download to convert DD to DMS.  For example, I want to convert from:  41.590833, -93.620833 to 41° 35′ 27″ N, 93° 37′ 15″ W ...  Those are the coordinates, according to , for Des Moines.


Let $a_n$ be a sequence s.t $a_1 > 0 \land a_{n+1} = a_n + \dfrac{1}{a_n}$. Prove that $a_n$ is increasing and tends to infinity

Let $a_n$ be a sequence s.t $a_1 > 0 \land a_{n+1} = a_n + \frac{1}{a_n}$. Prove that $a_n$ is increasing and tends to infinity.  Proof:   Consider $a_{n+1} - a_n$:  $a_{n+1} - a_n = a_n + \frac{1}{a_n} - a_n = \frac{1}{a_n}$ This is greater than $0$. Thus, $a_n$ is increasing.  Now this is where I need some help. I would like to say that $a_n$ is unbounded and then conclude that monotone and unbounded implies tending to infinity.  Maybe by contradiction?


Upgraded to Ubuntu 20.04 and now my task manager displays strange icons

I upgraded to Ubuntu 20.04 and now my task manager is unusable because it displays a weird  icon font. How can I fix this? Thanks!


How to copy a file from a remote server to a local machine?

In my terminal shell, I ssh'ed into a remote server, and I cd to the directory I want.   Now in this directory, there is a file called table that I want to copy to my local machine /home/me/Desktop.   How can I do this?  I tried scp table /home/me/Desktop but it gave an error about no such file or directory.   Does anyone know how to do this?


let $x,y,z,w\in R$,and such $x+y+z+w=2$.show that $$\sum_{cyc}\dfrac{x}{x^2-x+1}\le\dfrac{8}{3}$$  I have only solve when $x,y,z,w>0$, because  $$\dfrac{x}{x^2-x+1}\le\dfrac{4}{3}x$$ so  $$\sum_{cyc}\dfrac{x}{x^2-x+1}\le\sum\dfrac{4x}{3}=\dfrac{8}{3}$$


How to add some shortcut for editing in TeXstudio

I would like to add some "commands for editing" in TeXstudio. For instance in the menu "TI" on the left which stands for 'TikZ', there is some "commands for éditing" TikZ commands, you click on it and you have some squeleton of commands in your source file, and you just have to modify it to custom it.  I would like to add some personnal "commands for editing". Is it possible to do it in TeXstudio, and if yes, how do we do that ?


I am new to ubuntu server and I cannot find this information online.  When I login via SSH I am in:  root@Ubunutu ~ #   I used mkdir mydir to create a folder, but I cannot find it anywhere (using filezilla).  I also do not understand what ~ means, where am I?  I can use cd .. then it will show root@Ubunutu / #, which I understand. From here I can use ls to see folders.  To summarize:  What does ~ mean, which location is it?  Where is my folder?


What is the difference between a parametric test and non-parametric tests?

Please explain the difference between a parametric and a non-parametric test.  Do all data mining techniques come under the non-parametric category?


Stackoverflow Careers Site not pulling all Github open source contributions

When I click the Github button under Open Source Contributions, I only see my own repos and a couple of the repos that I have made contributions to; there are about 5+ other repos that I have made contributions to which are not showing up at all, and I can't add them manually using "other".  Furthermore, there is no difference in the couple of non-owned repos I have contributed to that DO show up, and the others that DON'T show up; I made just as many, if not more, contributions to the ones that are missing.    How can I fix this?  Is there no other way to manually add Github open source contributions?


Installation of Openstack via autopilot with only one Disk per Node

I plan to use autopilot to install a Openstack cloud on a bunch of servers, which have single SSDs installed. The requirements say, 2 disks per node are required, as stated here: .  The machines are currently in production use and we have a limited time frame to get everything up and running, so i have no chance to just give it a try, so after this lengthy preamble my question is:  Is it possible to install Openstack with autopilot on nodes, that have just one physical disk?


Why do operators belonging to different Hilbert spaces commute?

Every time I run into a commutator of two observables such as $[\hat{X},\hat{Y}]$, with $\hat{X}$ and $\hat{Y}$ being two operators from different state spaces: $\hat{X}\in\xi_{x}\land\hat{Y}\in\xi_{y}$; it is said that their commutator equals zero because each operator acts on its own subspace.   Could someone give the proof for that statement? Thank you.


CDN - Content Delivery Networks. How do they work and why would I want to use one?

What exactly is a Content Delivery Network (CDN), how does it work, and why would I want to use one for my web site?  Which are the well-known CDNs out there?


when the phrase "Can't complain" is pronounced [ˈkænt kəmˈpleɪn] I think that the T is dropped in fast speech because of the alveolar plosives. Right? I read that when T comes before these letters: / s, f, n, l, p, k / it's silent.  I know that in American English the T is held in "I can't do it" but above I'm talking about dropping it completely. I recorded myself:  Does it sound okay?


I have a school project about cryptography. The question is the following (will only give a short phrase as example, just want to know the method). A text has been encoded with Vigenere 2 times. The ciphertext is FXFCKDKFCLMHOSPERVBOPDJ (it's Dutch btw, you won't really get plausible words because I cut it off). It has first been encoded with a cipher of 3 letters, and then with a cipher of 2 letters. The first letter of the 2nd cipher is an O.


I shall travel to Mexico and then to the USA with a Lesotho passport. I have a 6 hour layover in London at Heathrow airport out of South Africa. I have a US visa in an old passport which is still valid until 2019.    DO I need a transit airside visa for London - I will not require to pass through customs/passport control while waiting at Heathrow.  DO I need to have my US visa transferred into my new passport before I leave home?  - Nothing has changed, such as my names in the new passport.


GNU Screen equivalent for X11 aplications

What is the X11 equivalent of GNU Screen for X11 applications? I know there is VNC, possibly RDP and other candidates, but last week when tuning up my VNC config I've stumbled upon a project, that was basically screen for X11 applications, i.e. you could start remote app wrapped in it, log out of the X11 session and later return to the application. Unluckily this wasn't a direct google hit and I cannot find it in the google history now. Any idea, what the name/url of the project might be ?


"By" vs "Per". Which one should I use on expressions like "P&L/Geography" or "VaR/Asset"?

In the finance field, it is quite common to express some measures in relation to some grouping criteria. Some groupings can be temporal (year, month, etc.) and others like greography, asset class (e.g. a financial product), strategy (used in trading), and others.   Which one is the most appropriate preposition to apply in this kind of expression ?    "VaR per asset" or "VaR by asset" "P&L per strategy" or "P&L by strategy".   Is there any well defined rule behind the most appropriate use ?


i have this string "1/20/2015 12:00:00 AM" and i need to convert in something like this  "20/1/2015" without time and days first.  DateTime mydate = Convert.ToDateTime(myDateFromDB);


Is it common to use an adjective as a noun without ‘the’ or the following word in the press headlines?

Washington Post November 29 issue reports Pope Francis has been encouraging Vatican’s charity activity under the headline: Pope ramps up charity office to be near poor, sick. It begins with the following sentence:  “Pope Francis has ramped up the Vatican’s charity work, sending his chief alms-giver and a contingent of Swiss guards onto the streets of Rome at night to do what he usually can’t do: comfort the poor and the homeless.”   Is it common to spare “the” or “people” in front, or after “poor” and “sick” like this in journalism English? To me you can not save much space by sparing 'the,' and ‘to be near poor, sick” sounds like “feel like being poor and sick.


Is it possible to have different cleartype and color settings in a multimonitor setup in Windows 8?

I just bought a Samsung 24C300HS and I have it connected to a Surface Pro. The color settings are horrible.  I used windows' "Calibrate color" to adjust the color and clearType settings and with that I can get a very reasonable image that I'm happy with, the problem is that it also changes the settings on the Surface Pro screen, making that one miserable.  Is there any way to get around this? For example having different color profiles for each monitor, or if not possible, is it possible to save the settings so that I can change them quickly without having to go through the Calibrate Color tool?


How to get Texmaker to place all files into a folder upon compile

Mac user here. I'm getting too many files whenever I compile a latex document, and so often each time a make a new file I have to make a folder with the same name to put all of the .pdf, .tex, .aux, etc files in just to clear up the finder.   I would prefer it if there were a setting in Texmaker that would automatically place all of the files into a folder with the document name, so that I don't always have to manually do so. Does anyone know of such a setting or other option?


How to automatically add a shortcut for removable media on Windows desktop, like some Linux distros?

I use sometimes some Linux distros, e.g. Ubuntu, and I like the feature they have to add a desktop shortcut to every removable device that is plugged in on desktop - for example, when a DVD is inserted, a new icon for that appears on desktop, and with that I can access, eject etc.  I would like to have the same feature for Windows - specifically for Windows XP Professional SP3, but it is interesting to know the solution for other Windows versions...  Any help?  PS1: I would like to have "dynamic shortcuts", i.e, shortcutes that appears on desktop when the removable device is inserted and that disappears when it is removed.  PS2: I'm talking about CD/DVD media and massive storage devices mainly.


Is there a way to see when an application was launched? I need to restore some tabs that were open in my browser when I launched it several weeks ago (it is still running) and I want to look in the browser history at the "launch moment".  I took a quick look in Console.app but there was just too much information.  It is about Firefox. I launched a couple of weeks ago and have since then closed a few tabs that were open when I launched and that I would like to restore. Everytime you launch and restore previous session there is an entry for each tab in the browser history. If I just could find this moment it would be easy to find my lost tabs


Main page of SO is telling me there are no questions

I clicked on the logo for Stack Overflow to go back to the home page and it told me no questions were found. This also happens when I open a new tab and go to stackoverflow.com.        My last view had been tags=WPF with the Needs Answer tab selected, so I know there are plenty of questions here.  I had noticed going back to the main page was being obnoxiously slow today, so suspect this is just a timeout instead of an actual problem with no results found.  Can you fix the slowness of going back to the main page of SO by clicking on the logo? Alternatively, perhaps load the default SO page if a timeout occurs retrieving the user's last used question filter.  (PS. I'm  of having the logo go back to the default view of SO in all cases, with no filters applied. That would be my preferred "solution") :)  Edit I do not think this is an exact duplicate of  because I obtained this message by going to StackOverflow's homepage, not by using search results. In addition, the only answer posted there is .   Having a message that there are no questions on the homepage seems like a bigger deal than encountering that message when searching, and additional code may be required to handle this correctly.  Edit #2 I just went to stackoverflow.com from a new browser window, and got the same error screen.   I didn't realize my previous filter was cached and re-used when I visit the page in a separate session. This seems like something that should definitely be addressed if timeout issues are common.


I know an Automorphism is a group $G$ that is an isomorphism where $h:G \rightarrow G$, (G is being mapped to itself) and that $\text{Aut}(G)$ is the set of all Automorphisms in G. I was wondering how I would approach finding all functions in $\text{Aut}(\mathbb{Z}_n)$, let's say $\text{Aut}(\mathbb{Z}_4)$ for example. Is it as trivial as showing a bijective map from each element in $\mathbb{Z}_4$ to itself?


How needed is the Image Stabilization on the Canon 70-200 f2.8 L USM lens?

I just picked up photography a few months ago as a hobby (not planning to go professional at all), but will be getting good gear and glass over time. Right now I have a T3i, which I'm considering upgrading to a 7D or probably a used 5d Mk II next year.  For my next lens purchase, I'm considering a 70-200 L lens, I'm just not sure which one to go for.  I'm deciding between the 70-200 2.8 L with no IS, or the 70-200 f4 L with IS.  My thinking is the following:   While I do not plan to photograph weddings or anything like that, I do plan to use the lens to take pictures of my kid on school plays over the years, so I'm guessing the 2.8 would be useful there? He's not on school yet, but I hear flash is not allowed there? How would the f4 fare in such situations? I have the 18-135 kit lens with IS...I turned off the Image Stabilization on the lens, and was able to take decent pictures handheld with not-so-fast shutter speeds (1/15, 1/20's), although I do NOT have a good pulse. Would being able to do this translate well to using the 2.8 with no IS? Most of the shooting with the 70-200 will probably be done outside..just that case of shooting plays or a concert or too.   So..what should I do? Anything I'm not considering?


Does the concept of the Abrahamic god exist in the galaxy far, far away?

As noted in  question, the concepts of heaven and hell appear to exist in the galaxy far, far away;  Han even mentions the latter in The Empire Strikes Back:  RANDOM JERK REBEL GUY:  Your Tauntaun will freeze before you reach the first marker! HAN SOLO:  Then I'll see you in HELL!  The modern concepts of heaven and hell have their origins in the so-called Abrahamic religions:  Christianity, Judaism, and Islam. Therefore, since the galaxy far, far away has heaven and hell, it is logical to ask if the galaxy far, far away has some concept of the Abrahamic god. Adding fuel to the fire, DVK's answer  notes that Han's freighter contains a compartment he hasn't been able to open.  The ID number on the compartment is identical to the ID number on the crate in which the Ark of the Covenant is stored in Raiders of the Lost Ark.  Surely, if a holy relic associated with the Abrahamic god of Judaism is referenced (and perhaps located) in the galaxy far, far away, it is sensible to ask if that same god is known to some of the galaxy's inhabitants in some form or another.   Does the concept of the Abrahamic god of Judaism, Christianity, and Islam exist (in any form, or to any degree) in the galaxy far, far away? Note 1: I don't think this is addressed in the movies, and although I would prefer a canonical answer, Legends will do, if nothing else is available.  However, the Star Wars Holiday Special is not an acceptable source. Note 2:  The substance of this question is fundamentally different from "Do Heaven and Hell exist in Star Wars", because that question and its answers don't address the Abrammic god in any way.


I use Ubuntu 16.04.5. I had decided to try Plasma 5 desktop and did this:   sudo add-apt-repository ppa:kubuntu-ppa/backports  sudo apt update  sudo apt install kubuntu-desktop   I've kept lightdm during installation. After the process finished I faced several problems with Plasma 5: It loaded dramatically slow and showed several windows with error messages. Moreover it ate 70% of my RAM which is ~2.5 Gb.  I had switched to Unity in login manager and deleted Plasma:   sudo add-apt-repository -r ppa:kubuntu-ppa/backports  sudo apt purge kubuntu-desktop  sudo apt autoremove   But it looks some parts of kde are still in my system: I see KDE default cursor in login manager and in some Qt applications and when I turn on my computer I see Kubuntu logo instead of Ubuntu. I can live with startup logo but appearance of KDE cursor sometimes is annoying. How to fix it?


GPG error; The following signatures were invalid KEYEXPIRED

sudo apt-get update   get this error:  W: GPG error: http://debian.datastax.com stable Release: The following signatures were invalid: KEYEXPIRED 1439480363 KEYEXPIRED 1439480363 KEYEXPIRED 1439480363   even after use --fix-missing, still have the same error.


What does NOEXEC flag mean when mounting directories on RHEL?

I am trying to understand the NOEXEC flag when mounting.  I am having an execution issue within the /tmp directory on someone elses machine that I cannot access atm where the /tmp directory is mounted onto a different drive than '/' and NOEXEC is present.  I wanted to try and recreate this scenario on my machine, but I do not have a second hard drive.  I tried doing the following command:  mount --bind /test1 /test2   I then removed the bind flag and added NOEXEC in /etc/fstab.  Then, I created a file in /test2 called test.sh where it just echos 'hello world'.  I try and run it and it said 'permission denied'.  I then ran chmod 777 test.sh and was able to execute the file just fine.  I thought that the NOEXEC flag should not allow me to execute anything?  Is mount --bind /test1 /test2 not the same as mounting from a completely different physical drive? As in /test1 and /test2 are on different drives?


I made a pair of eyes for a character of mine that consists of two meshes. One that acts as the real eye with the iris and the pupil, and then a copy of that one but slightly different to represent a cornea which has only a simple glass shader on. Why are the eyes of my character dark as soon as I place them inside the eye sockets? Seriously, you can barely see them. Can anyone tell me why Blender does this?  Eye out of socket:    Eye inside socket:    From a distance you can't see it's eyes at all, only if you're this close can you make them out.  Blend file:


How do I round this float decimal to two decimal places?

I am new to python and am having some difficulties. How would I make this so that I can round the float(roll)*100 rounded to 2 decimal places.   for x in roll1:         print('%d - %d %f%%' %(x,roll1[x], float(roll1[x])/float(roll)*100))   This is the output currently. I need to make the numbers rounded to 2 decimal places. Thanks!  1 - 1794 17.940000% 2 - 1620 16.200000% 3 - 1620 16.200000% 4 - 1611 16.110000% 5 - 1650 16.500000% 6 - 1705 17.050000%


How to see a list of Custom Object created date?

I can I see a list/report of custom objects with Created Date listed as a column ?   Is this something I can do in Workbench...?


Why would Emperor Palpatine make himself vulnerable to Darth Vader at the end of Return of the Jedi?

At the end of The Return of the Jedi, the emperor tells Luke just after Luke defeated Vader in a duel,  "Now fulfill your destiny and take your father's place at my side."  If I was Vader, I would be thinking, "Palpatine is just going to throw my life away like he did Count Dooku. I'm a goner unless I take out the emperor soon!"  The Emperor then turns his back on Darth Vader while zapping Luke with bolts of electricity. Palpatine should know not to trust Vader. He seems so engrossed in torturing Luke that he doesn't notice Vader walking up behind him and grabbing him. He should know not to trust Vader for a second. He knows a Sith apprentice becomes a master by killing the previous master. He could have killed Luke quickly and then kill Vader, instead of spending almost two minutes torturing Luke. He also had a chance to zap Vader a couple of times when Vader was nearly helpless, lying there on the bridge before getting up to stand by his master's side. One zap to Vader's breather would probably have short-circuited it. Why did he make himself vulnerable to Darth Vader? Edit to address why this is not a duplicate of another question. The other question focuses on whether Palpatine erred in torturing Luke in front of his father. Palpatine already suspects Vader's feelings for Luke.  Palpatine: Strange that I have not felt him. Are your feelings clear on this? Vader: They are clear, my lord.  My question is about why Palpatine would trust Vader since he knows the Rule of Two. It is a Sith tradition for Sith Lords to kill their masters (or apprentices). He should know to never trust Vader for even half a second, yet he makes himself vulnerable for almost two minutes. That was all the time Vader needed to pick up the Emperor and throw him down the elevator shaft.


EdExcel GCSE question about Hannah and the sweets: show that $n^2-n=90$

This is my reconstruction of the EdExcel GCSE question that has caused such a  in the UK in the last 24 hours, along with its solution.    Hannah has a bag containing $n$ sweets, 6 of which are orange. She eats two sweets at random from the bag.  The probability that the two sweets Hannah eats are both orange is $\frac{1}{3}$. Show that $n^2 - n = 90$.    Possible follow-up (I don't know if this was part of the original): how many sweets were there in total in the bag?


How to resolve "Something wicked happened resolving 'your_proxy: 800'"?

I am not able to install any packages from terminal or software center.      Something wicked happened resolving 'your_proxy: 800' (-5 - No address associated with hostname).    This error pops up. I need help.


How can I make Ubuntu 18.04 / 18.10 desktop use Unity (be like Ubuntu 14.04)?

I recently installed Ubuntu 18.04 and I'm not keen on the desktop environment. I want the desktop env. I used to have in Ubuntu 14.04. How can I get it?  I've attempted to use , but when I try to install the Unity's 7.2.5 version using the command:  apt install unity=7.2.5   it gives me   E: Version '7.2.5' for 'unity' was not found   For sure I need to add a PPA for this, but which one!?


Nomination owner highlight is displayer in the comments only after clicking the "show n more comments" link

When navigating to the , in the comments section, by default there is no highlight for the nomination owner.  But when I click the "show n more comments" link at the end of the comments section, after all the comments are loaded, there is a highlight applied for the nomination user in their comments.  It seems owner CSS class is added after the click of "show n more comments" link, which caused the inconsistency.  GIF for the same


Command line to create a PDF document from a batch of images

How to create a PDF document from a batch of images ?  ===  Belowis what I tried before posting this question:  The ImageMagick way, but the PDF document generated is too big:  convert *.ppm book.pdf   The Preview tool way, the created document is much smaller but it creates margins.  The sips way, not working for some reason:  sips -s format pdf *.ppm --out 'book.pdf' 1>/dev/null 2>&1   There also img2pdf which looks good but I couldn't install it on mac (it's not in brew's list of packages).


If krull dimension is $0$, then all prime ideals are maximal?

Let $R$ be a ring, If we assume '$R$'s all prime ideals are maximal',then we can say $R$'s krull dimension is exactly $0$. This is easy because there are two different prime ideal $p$ and $q$ which satisfies $p⊂q⊂R$, and this contradicts the fact that $p$ is maximal.  But is the converse true?  my attempt: If there are prime ideal $p$ which is not maximal, then there are another ideal $q$ which satisfies $p⊂q⊂R$. If I can deduce $q$ is prime ideal, the proof are done.But I cannot show $q$ is a prime ideal.  Any help would be appreciated, thank you.


How to create assignment border matrix like this

I want  to create assignment matrix like this  \usepackage{kbordermatrix,blkarray} \usepackage{amsmath} \usepackage{amsmath,stackengine} \stackMath \[ \stackinset{c}{-2.8\baselineskip}{c}{}{\rule{.4pt}{5.2\baselineskip}}{% \stackinset{c}{1.9\baselineskip}{c}{}{\rule{.4pt}{5.2\baselineskip}}{% \stackinset{c}{3.1\baselineskip}{c}{}{\rule{.4pt}{5.2\baselineskip}}{% \stackinset{c}{}{c}{2\baselineskip}{\rule{6.9\baselineskip}{.4pt}}{% \stackinset{c}{}{c}{-3\baselineskip}{\rule{6.9\baselineskip}{.4pt}}{% \bbordermatrix{ & 1 & 2 & 3 & 4 & 5 & 6 \cr               1 & 1.5 & 3.5 & 1 & (1) & 1 & 4 \cr               2 & 1.8 & (1) & 3.1 & 2.6 & 1.9 & 1.8 \cr               3 & (1) & 1 & 1 & 1.4 & 1.1 & 2.1 \cr               4 & 3.8 & 4 & (1) & 5.6 & 2.8 & 2.2 \cr               5 & 3 & 3.3 & 1 & 4.6 & 4.6 & 5  \cr               6 & 4.8 & 4.9 & 3.2 & 5.5 & 2.8 & (1) \cr               }}}}}} \]


torque on a body without any supporting point

Suppose there is a rigid body in space and one single force is acting on it and the force does not pass through the center of mass. I would like to ask why the torque on a body is always the force times perpendicular distance to the center of mass if there is no supporting point on that body? What's the principle behind that?


I want to ask how to install package in Ubuntu 14.04 using terminal  I need a command to do that and also a command that works with most of package to install


When you don't understand a joke right away

In my native language we have lots of ways (some of them very funny) of saying that you, or someone else didn't understand a joke right away. That is, he/she needed some time to figure it out.  I wonder if there's any idiomatic way of expressing that in English.


A problem from abstract algebra of finite group?

A and B are to nonempty subset of a group G with $|A|+|B| > |G|$ then G = AB.  I am a bit confused of the order of a subset of a group. Generally a subset of a group is not a subgroup but when it occurs $|A|+|B| > |G|$, I want to figure out the relation between A and B and if A will have the inverse of some elements of A if $|A| > \frac{|G|}{2}$?


Want to pursue a PhD in Philosophy, but my Master degree is in Fine Arts (Painting). I want to know how likely will I be considered for the program? I have art history and Aesthetics, as my theory in Bfa and Ma.


$query  = $this->db->prepare("INSERT INTO `images` (`anunt`, `image_location`) VALUES(?, ?)");          $query->bindValue(1, $iddd);         $query->bindValue(2, $image_location);           try{         $query->execute();   or this  $ret = sql_query("INSERT INTO images (anunt, image_location) VALUES ('" .$iddd. "', '" .$image_location. "')");   Or another way maybe? What advantages are with the bind one? I read something that it's hard to sql inject.


What Does it Really Mean to Have Different Kinds of Infinities?

Can someone explain to me how there can be different kinds of infinities?  I was reading "" by  and came across the concept of countable and uncountable infinities, but they're only words to me.  Any help would be appreciated.


How do you achieve this brownish skin color moody look on your photos?

I've noticed that there is quite popular style of moody photographs with rich shadows, muted colors and very specific brownish-like skin-tone. It does seem to come from some kind of post-processing technique. What are the ways to achieve similar look?


Will UbuntuTouch run on the Nexus 5 device?

Now, you can see my question above. Will Ubuntu Touch run on the Nexus 5 device. And/Or will Canonical support the Nexus 5 device?  Because I will buy a Nexus 5 and I would like to use Ubuntu Touch on it.  Greetz and thanks.  Ralf Lange


How To Delete This Red Box on My Screen?

I was editing my mesh and I wanted to only see a part of my mesh, so I pressed alt+B to only show a selected area. However, I did ctrl+B and created a red rectangle on my screen (I don't know what it does). Does anybody know how to get it off?


Is "incorrect facts" a contradiction in terms?

I've seen this so many times and it drives me crazy. The latest was the actor Paul Giamatti setting some story straight in the press about him: "It's unfortunately an incorrect fact about me and it's all over the place."  I've seen this written so many times, in magazines, books, but surely a fact is, by definition, true. So there cannot be any such thing as a "false" fact. Right?


Why does cross product give a vector which is perpendicular to a plane

I was wondering if anyone could give me the intuition behind the cross product of two vectors $\textbf{a}$ and $\textbf{b}$. Why does their cross product $\textbf{n} = \textbf{a} \times \textbf{b}$  give me a vector which is perpendicular to a plane?  I know I can just check this by using dot product but I'm not totally satisfied with "it just works" answer =)  Thank you for any help! =)


How can I enable compiz effects on Gnome3 on ubuntu 11.10?  I already installed ccsm and compiz-plugins-extra.  What else should I do?


Book series that follows a student of magic who is expelled after a teacher is killed

I am looking for a book series that I read between 1988 and 2000, but I can't recall the title or the name. The first book starts with the main character being chosen to learn magic. By the end of the book, he is decent at the rudimentary spells but does not progress any farther as he is banished from the school due to his involvement with killing a teacher. The series goes on with him learning different spells such as shapeshifting, and time travel with each book. There is a particular book that features him fighting off the influences of a statue that he finds with the cover art of the main character overlooking a stormy ocean with the old woman standing in front of him with her back turned. There is a particular scene that I can remember where the main character, now much older, is attempting to gain access to a castle but is blocked by magic wards. To remove the wards, he must strike a bell tower with a bolt of lighting at an exact time. He fails to hit the tower but sees a second bolt of lighting appear from seeming nowhere to hit the tower. He later discovers that this second bolt of lighting was from a version of himself that had learned to travel back in time.


My question is that if on a FREE HIT a batsman gets and inside edge and ball hits the stumps, can he take runs on that ball?


Ruby - Calling setters from within an object

I've been working through the Pragmatic Programmers  'Programming Ruby' book and was wondering if it was possible to call a setter method within a class rather than just assigning to the instance variable directly.  class BookInStock    attr_reader :isbn, :price    def initialize (isbn, price)     @isbn = isbn     @price = Float(price)   end    def price_in_cents     Integer(price*100 + 0.5)   end    def price_in_cents=(cents)     @price = cents/100.0   end    def price=(dollars)     price = dollars if dollars > 0   end  end   In this case I am using a setter to ensure that the price can't be negative. What i want to know is if it is possible to call the price setter from within the price_in_cents setter so that I wont have to write extra code to ensure that the price will be positive.  Thanks in advance


How to find the following intergal:  $$\mathcal{I}_\text{n}:=\int_0^\infty\frac{x^\text{n}}{1+x^2}\space\text{d}x\tag1$$  I've no idea where to start, I've tried integration by parts but it lead not to a closed form.


I don't know what happened but whenever I start Chrome this message pops up:    My home page has changed to this one:    Whenever I open a new tab, the main Google Search icon disappears and only recommended tabs are shown. The Google+ profile tab is also gone. How can I fix this?


How to store result in a variable when Verifyelement not present is failed in Selenium IDE

I want to verify an element present in screen or not and store result in variable if it is present  I want an output like true or false in a variable and return this variable to flow (Power automate) Please suggest ideas how to do this ?


What was John Napier's motivation to introduce the logarithmic function?  It neither makes the calculations easier nor accurate (at least for me). How could people think of its importance even before Calculus came into play and showed its connection with the exponential function or, area under the graph $\dfrac{1}{x}$ ?


Taking a File Argument and Moving to That Directory?

Is there a Unix command or shell script that takes a file argument and moves to the containing directory, ignoring the file part of the argument altogether?


Child who entered under ESTA/VWP accompanying US citizen mother

When entering the US, I informed the Immigration officer that I was coming home on maternity leave (to give birth and stay for 4 months). My 3-year-old son, a French citizen and eligible for US citizenship, is with me. Now that we are in the US, I have access to all the paperwork required to get his and the baby's US passports, and we plan to leave with those passports to get return to my (non-military) duty station in Asia.   Advice on what to do [as my son entered under the VWP/ESTA and will be in the country longer than 90 days]?   I don't want his French passport to have a black mark or him being barred from re-entry in the future. I also don't plan to spend 370 USD on a visa extension since we are getting their passports in order.


Fields finitely generated as $\mathbb Z$-algebras are finite?

Suppose $k$ is a field that is finitely generated as a ${\mathbb Z}$-algebra.  (That is, $k$ is a quotient of ${\mathbb Z}[X_1,\dots,X_n]$ for some $n$). Does it follow that $k$ is finite?


I need to draw (simple) movement arrows in linguex examples. I would normally use the tree-dvips package for that (as in the LaTeX example below) but this time I must use XeLaTeX, which is incompatible with tree-dvips. What is an alternative that you can recommend? Note that I do not need to use arrows more complex that what's in the example.  \documentclass{article} \usepackage{linguex} \usepackage{tree-dvips} \usepackage{linguex}  \begin{document}  \ex.    ta\node{tgt}rget {} \dots {} \node{trace}t    \abarnodeconnect[-9pt]{trace}{tgt}  \end{document}


sum of exponentially distributed random numbers

I have a set of exponentially distributed random variables $X_i \sim \exp(\mu_i)$ with rates being also random with some distribution. Is there a way to find the distribution (or the CDF if it is easier) of $Y$ the sum of $X_i$,  $$Y=\sum\limits_{i=1}^N X_i,$$  other than the following:  $$f_Y(x) = \sum\limits_{i=1}^N \prod\limits_{j=i} \frac{\mu_i}{\mu_j-\mu_i} \mu_i e^{-\mu_i x}. $$  I found the above expression earlier, where $\mu_i$ is different for each $X_i$, but in my case, the rates are random with some distribution $f_\mu (\mu)$.   Is there any other expression for the sum?  Edit: My Question was marked as duplicate, but I never found where the duplicate original was. As far as I can see, the closest questions are either dealing with identical rates of the exponential, which is not my case or had the formula that I stated, which is not helpful for me.


I am trying to realize a certain mathematical combination into Javascript but can find the best way to do it. What I am trying to achieve is finding the sum of combinations(consisting of 3 elements) out of N. For example, how can I find sum of all possible combinations consisting of 3 elements out of 5? Manually it looks like this: Selections: A,B,C,D,E  - all of them are numbers All possible 3 out of 5 combos are as follows: ABC ABD ABE ACD ACE ADE BCD BCE BDE CDE ABC means A * B * C The sum of combos in its simplified form will look like this: AB(C+D+E) + AC(D+E) + ADE + BC(D+E) + BDE + CDE. I have tried the following code but it did not work out: function calc(arr) {   var total = 0;   for (let i = 0; i < arr.length; i++) {     let sum = 0;     for (let j = i + 1; j < arr.length; j++) {       sum += arr[j] + arr[j + 1] + arr[j + 2];     }     total += sum * arr[i] + arr[i + 1] + arr[i + 2];   }   return total; }  var arr = [2, 3, 4, 5, 6]; console.log(calc(arr));


How to fix compile error with unexpanded parameter pack

I get a error for an unexpanded parameter pack while expanding it.  This code is for testing purposes.  Later i want to call a differrent function with the head, tail and element. I need the element to call another template function and want to maintain the other argument to later call a different template function.  Current output of clang (version: 8.0.0)  test.cpp  #include <iostream>  template <int... Tail> class for_each_type {     public:     template <int element, int... Head>     int each() {         for_each_type<Tail..., element> _for;          _for.each<Head...>();         return element;     }      template <int element>     int each() {         return element;     } };  int main() {     for_each_type<> _for;      std::cout << _for.each<1, 1, 2, 2>() << std::endl; }   I expect the code to output 6, but the actual output is a error message.  To run start the compiler i just run clang++ test.cpp  The current error message is:  C:\Users\HP\Documents\GitHub\CPP-Game-Engine\src>clang++ test.cpp test.cpp:10:23: error: expected ';' after expression         _for.each<Head...>();                       ^                       ; test.cpp:10:9: error: expression contains unexpanded parameter pack 'Head'         _for.each<Head...>();         ^         ~~~~ test.cpp:10:23: error: expected expression         _for.each<Head...>();                       ^ 3 errors generated.


Why are Hamiltonian Mechanics well-defined?

I have encountered a problem while re-reading the formalism of Hamiltonian mechanics, and it lies in a very simple remark.   Indeed, if I am not mistaken, when we want to do mechanics using the Hamiltonian instead of the Lagrangian, we perform a Legendre tranformation on the Lagrangian to get the Hamiltonian. This, in the case of a 1 dimensional problem, is written as follows: $$ H(p,q) = p\dot{q}-L(q,\dot{q}).$$ Notice that this transformation is such that $H=H(p,q)$, where $p = \frac{\partial L}{\partial \dot{q}}$. By variation of $H$, we can indeed verify it as function of $p$ and $q$, so that they are now considered the new independent variables of the problem.  So far so good. However, there is a problem, and it lies in the fact that for this construction to hold, we need the Lagrangian not to change convexity. Let me write what I know about the Legendre transformation, in a somewhat formal way:  Given a function $f: x\rightarrow f(x)$, we define the function $p: x\rightarrow p(x)$ by the relation $\frac{df}{dx} = p$. Supposing $\frac{df}{dx}$ is invertible, we can define the inverse of $p(x)$, which we call $g : p\rightarrow g(p)$. Then, the legendre transformation of $f$ is $f^* : p\rightarrow f^*(p)$ such that $\frac{df^*}{dp}=g(p)$. We can write, in a more familiar way, $g(p) = x(p)$ since it is the inverse of $p(x)$.  Anyway, we can prove with those assumption that $f^* = pg(p)-f(g(p))$ which is $f^* = px-f(x)$ written in the "familiar" way. All that is just to point out that, for all this construction to work, and hence for the existence of $f^*$, we need the condition that $f(x)$ be of constant convexity, otherwise $\frac{df}{dx}$ is not invertible and we cannot even define $g(p)$.  However, when we consider a general Lagrangian, I don't think that this is always the case. Taking simply $L = \dot{q}^3$ makes the Lagrangian not of constant convexity. And yet, we always use the Hamiltonian, without ever checking this convexity constraint. Why can we do this? Is it because we are interested in the local behavior of our Lagrangian? But even then, what would we do at an inflexion point?   Or is it because a general "physical" Lagrangian will always satisfy the condition of constant convexity?


If two integrals are equal, then the functions are the same

Assume that we have two continuous functions $f(x)$ and $g(x)$. If the integrals $\int_{x_1}^{x_2}f dx$ and $\int_{x_1}^{x_2}g dx$ are the same for any choice of $x_1$ and $x_2$, then the functions are also the same?  My attempt: I fix $x_1$ and let $x_2$ vary. Then I take the derivative of both integrals. It sounds right. I am missing something? Any better solution?


Upgrading from Ubuntu 16.04 to 18.04 broke the system completely!

I tried to upgrade from Ubuntu 16.04 to Ubuntu 18.04. First, after downloading and installing of packages, I was unable to login. Login screen hanged completely and it showed Failed to authenticate. But then I logged into tty1 and then logged in Ubuntu. It was saying that I am in Ubuntu 18.04. Then it asked for reboot. So I rebooted Ubuntu from terminal. It got stuck at something like /dev/sda4 : Cleaning files. After trying for a few times, I got into tty1 and here I logged in as root user and tried to update and upgrade. But now I am getting errors like unmet dependencies and broken packages. I have done sudo dpkg -- configure -a. I don't want to do a reinstall of Ubuntu. How do I get access to my Ubuntu Desktop?


Should every table have a single-field surrogate/artificial primary key?

I understand one benefit of surrogate/artificial keys in general - they do not change and that can be very convenient. This is true whether they are single or multiple field - as long as they are 'artificial'.  However, it sometimes seems to be a matter of policy to have an auto-incrementing integer field as the primary key of each table. Is this always the best idea to have such a single-field key and why (or why not)?  To be clear, this question is not about artificial vs natural - but about whether all artificial keys should be single-field


I was looking at how to find trinomial coefficients with code and I was puzzled with this equation.  $$\binom n k _2 = \binom{n}{-k}_2$$ I know that (nCk) represents n choose k but what does the 2 at the bottom right do compared to binomial?


Sufficient condition for the inverse of a matrix

Let $A$ be a square matrix. Another square matrix $B$ is called inverse of $A$ if $$AB=BA=I.$$ My question is whether just $AB=I$ or $BA=I$ is not sufficient to call $B$ as the inverse of $A$? If it is not, then give a counter example where $AB=I$, but $AB\ne BA.$


Thanks Dialog not in place when flagging for "No longer needed"

I just flagged a comment as it was no longer needed, over at The Workplace. After flagging, the new "Thanks for flagging" green dialog appeared, but it was positioned strangely (near the corner of the Top Bar), when I recall it appeared near the flag:    This happened to me on Firefox on my Ubuntu OS.  Note that this is not a duplicate, because the other question is only about the previous case where this happens only when the comment is automatically deleted, while this problem seems to be happening all the time, even when it's not automatically deleted.


How can we change the symbol to be in right side and the label description will be in the left side in qgis 3.6?


Vertically align multiple lines of text in a div

I'm currently writing a RSS parser and I use Ractive to generate the view. I'm trying to vertically align the contents of .feed-text-offset according to the height of .feed-item.  How can I accomplish this?  Demo:   The output HTML is like this:

         Text here         1 hr

   CSS  .feed-item {     padding: 2px;     background-color: green;     float:left; }  .feed-item-since {     font-size: 0.8em;     font-weight: 400;     margin-top: 5px;     display: block; }  .news-img-container {     width: 125px;     float: left; }  .feed-text-offset {     margin-left: 130px; }


SFDX Pull fails because of AppMenu/AppSwitcher

I created a scratch org with the new Winter release. After pushing my code without trouble, and updated it, I wanted to pull it to local files using :  sfdx force:source:pull --forceoverwrite -u myScratch   Now this error showed up : ERROR:  Metadata API received improper input. Please ensure file name and capitalization is correct. Load of metadata from db failed for metadata of type:AppMenu and file name:AppSwitcher.  Thing is, push works and I haven't modified an App. Also note that it worked on a older scratch with Summer release.  I'll take any idea or advice. Thank you for helping.


Error messages in terminal when using sudo to run apps as root

When running gedit with sudo, editing and saving a file causes the following error to appear (twice). Note that the first time it appears is when the file is edited in any way - even just pressing the space bar. Then it happens again when saving.  (gedit:4063): Gtk-WARNING **: Calling Inhibit failed: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files  (gedit:4063): Gtk-WARNING **: Calling Inhibit failed: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files   This did not always occur, but started recently. It seems to be a non-fatal error. Can it be corrected?  I am using 14.04 LTS. I use Unity but supplement it with Docky and Classic Menu Indicator Applet.  When running sudo nautilus, a similar error occurs:  (nautilus:4604): Gtk-WARNING **: Failed to register client: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files Nautilus-Share-Message: Called "net usershare info" but it failed: 'net usershare' returned error 255: net usershare: cannot open usershare directory /var/lib/samba/usershares. Error No such file or directory Please ask your system administrator to enable user sharing.   Again, this did not occur until recently, so I believe the problems are related.


Proving group is cyclic without Fundamental Theorem of finite Abelian groups?

I am stuck on the following exercise:     Let $G$ be a finite Abelian group that does not contain a subgroup isomorphic to $\mathbb Z_p \oplus \mathbb Z_p$ for any prime $p$. Prove that $G$ is cyclic.   This exercise comes before the chapter about fundamental theorem of finite Abelian groups and before the chapter about normal subgroups. Some of the chapters before the exercise are: cyclic groups, cosets and Lagrange's theorem, direct products.   So I assume there is a proof only using these tools (unless it is an accident and the exercise was meant to come later in the book).  Here is the idea I had:  Proof by contraposition: Assume $G$ is finite Abelian and not cyclic.   Then it contains two different subgroups of the same order (Although I'm not sure I can really deduce that since perhaps only the implication "cyclic implies contains exactly one subgroups per divisor of the order" holds)  Say they have order $n$. Let $p$ be a prime divisor of $n$. Now I want to deduce that each subgroup contains a copy of $\mathbb Z_p$ but I believe this might not be true.  Also, if we did have two disjoint copies of $\mathbb Z_p$ in $G$ then it's not clear to me how to get to $\mathbb Z_p \oplus \mathbb Z_p$ from there.     Please could someone tell me how to prove this?


Maximum of a Sample from a Uniform Distribution:  Suppose $X_1, ...  , X_n$ is a random sample for a $\mathrm{uniform}(0,\theta)$ distribution. Suppose $\theta$ is unknown. An intuitive estimate of $\theta$ is the maximum of a sample. Let $Y_n = \max\{X_1, ... , X_n\}$. Exercise 5.1.4 shows that the cdf of $Y_n$ is   $F_{Y_n}(t) = 1$ if $t>\theta$, $F_{Y_n}(t) = \frac{t^n}{\theta^n}$ if $0 < t \leq \theta$, and $F_{Y_n}(t) = 0$ if $t\le0$.   Then the pdf of $Y_n$ is $f_{Y_n}(t) = \frac{nt^{n-1}}{\theta^n}$ if $0 < t \leq \theta$, and $f_{Y_n}(t) = 0$ elsewhere.  Based on its pdf, it is easy to show that $E(Y_n) = (n/(n+1))\theta$. Thus, $Y_n$ is a biased estimator $\theta$... Further, based on the cdf of $Y_n$, it is easily seen that $Y_n$ converges to $\theta$ in probability.   MY QUESTION:     How do we know that $Y_n$ converges to $\theta$ in probability? Is it because $E(Y_n) \rightarrow \theta$?   Thanks in advance.


The difference between "Many a man" and "Many men"

Many a man died in that battle.   My understanding of many mean more than 2 and a man mean 1.  But in the sentence above, these two words are put together and I wonder what does it really mean? How can you have many one man died in that battle?


I want to use the diode 1N4571 (Vbrkdn=6.4V) and 1N4761 (Vbrkdn= 75V) in my circuit. Please help me design these zener diodes in LTSPICE.


How to pass data from child VF Component to Parent VF Component

I have two components, one component is a child of another component. I want to access value present in controller of child vf component in controller of parent vf component. Can anyone suggest how to do this? Thanks.


Operation 'Split, All The Metas!' Shall Commence On April 16, 2014

Update 2014-04-17 04:47 UTC: Stable, with some odds and ends to clean up      The main MSO/MSE sites are stable, but there are plenty of corners left to sweep. For details, see:    Not all of them mind you, just Meta Stack Overflow into Meta Stack Exchange.  I'll have you know, factually, that we really did believe this would take place in six-to-eight weeks when it was , but we've finally got a tentative date established.  If things go according to plan, we'll begin the operation shortly after 8:30 PM EDT on the 16th, completing everything within a few hour window. Ideally, all service disrupting endeavors will be completed within the first hour, which include:   The availability of Meta Stack Overflow The availability of Stack Overflow (more on this shortly) The availability of Chat on Meta Stack Overflow   As you know, we'll be bolting on a standard issue per-site meta on Stack Overflow, while breaking the link between what will have become Meta Stack Exchange and Stack Overflow. There's some irritable innards in that particular region, so we'll be asking folks to expect the unexpected during the maintenance window. Affected sites will be in and out of read-only mode, or quite possibly just down for maintenance while we're doing the actual break.  I'll be posting a system message on both Meta Stack Overflow as well as Stack Overflow itself 24 hours before we begin the actual work.   Did I say tentative in a six-to-eight-something time frame again? Why yes, I did - we're currently running some tests on the dev tier to simulate the split as closely as possible, so that we can better anticipate quirks that we need to address prior to actually doing it.  Once the sites have actually been stood up functionally on the production tier, we're going to get to work on finishing touches. This will include things like site settings (which determine bits of text you see in the question prompts, rep thresholds, etc) and all sorts of other fine tuning.  Once we're done:   Stack Overflow will have a blank, empty child meta site just like every other site The new Meta Stack Exchange will be up and running All rooms on Chat Meta Stack Overflow will be moved to Chat Meta Stack Exchange  I'll send over about 150 - 200 questions from MSE to MSO, most of which will be tag or SO-specific feature related posts that got buried by the network stuff without resolution.   If the tentative date moves, I'll update this post with the new date. However, we do not anticipate this happening any later than Saturday, April 19 - in the case that we see down time we can't mitigate and need to do it on a weekend.  The ground work is basically done, we're finishing up sanity now with a great deal of confidence, and we're pretty certain that we'll hit between those dates, if not directly on the tentative 16th.  Questions? Kvetch? Anonymous confessions? Answer below, and I'll address each in comments.


Why is the length of the Kelvin unit of temperature equal to that of the Celsius unit?

The Celsius unit is arbitrarily defined, based on the boiling and freezing point of water. Is it a coincidence, then, that the SI unit of temperature Kelvin, which is used in all natural equations, has the same length as the Celsius unit?


Is drag force on an oscillating sphere an effective model for a swimmer?

I saw the latest video from Sixty Symbols . At the end of the videos he says that we do not know how to calculate the movement of the little swimmers. He says(6:14-6:40 in video) that mathematicians derive formulas for small velocities and that they do not work for this experiment. This got me thinking.  Is the speed really that high? Have a look at visualization of the flow behind the swimmer, time in the video 4:32-4:47. The flow looks calm, there is no turbulence. Therefore the argument that the velocity is too high might not be the right one.  Stokes, Oseen, ... drag: I did the calculation for Stokes and Oseen drag and yes you get that the swimmer should not move. Even more, if you assume the drag force as any function of velocity, than the calculation says the swimmer should not move. Therefore deriving more accurate drag formulas for constantly moving sphere in liquid does not help.  Acceleration is too high, not the velocity: Next step in approximation is to derive drag force on single oscillating sphere in fluid. The question is, what is the drag force on the sphere which is moving with velocity $\mathbf{v} = \mathbf{ v}_0(1 + a \sin(\omega t))$?  Will this drag force predict movement of the swimmer? If not than it can be tested in the experiment by making the spring really long and no movement should be seen.    $ \newcommand{bm}{\mathbf} $ My calculations:  Center of mass of the whole system, its velocity and total mass are $x, v,m$  Position, velocity, radium, mass of $i$-th sphere are $ x_i,  v_i, r_i, m_i$.  Since $\bm x$ is center of mass than \begin{align} m_1  x_1 + m_2  x_2 &= m x \\ m_1 + m_2 &= m \end{align} Spheres are oscillating with frequency $\omega$ $$ x_1 - x_2 = L(1+\alpha \sin(\omega t)) $$ $L$ is rest length of spring, $\alpha$ is relative extension of the spring.  Thus \begin{align} x_1 &= x + \frac{m_2 L}{m}(1+\alpha \sin(\omega t)) \\ x_2 &=  x -\frac{m_1 L}{m}(1+\alpha \sin(\omega t)) \\ v_1 &= v + \frac{m_2\omega L}{m}\alpha \cos(\omega t) \\ v_2 &= v -\frac{m_1\omega L}{m}\alpha \cos(\omega t) \\  \end{align}  The force on the system is sum of forces on those two spheres \begin{align} F &= F_1 + F_2 \\ F_i &= f(v_i,r_i) \end{align} Force on the single sphere is a function $f$ of its velocity and its radius.  Stokes drag: $$ f(v,r) = 6\pi \mu r v $$ Thus $$ F_i = 6\pi \mu r_i \left( v + \frac{m_2\omega L}{m}\alpha \cos(\omega t) \right) $$ Averaging over period and assuming that the CoM velocity is constant over the period. $$ \hat F_i =\frac{\omega}{2\pi} \int_t^{t+\frac{2\pi}{\omega}} F_i = \frac{\omega}{2\pi}  \int_t^{t+\frac{2\pi}{\omega}} 6\pi \mu r_i \left( v + \frac{m_2\omega L}{m}\alpha \cos(\omega s) \right) ds = 6\pi \mu r_i v  $$  So the averaged force over the time period is the same as if no oscillation is happening.  In general Suppose that the swimmer is not moving, $v=0$. Again assume that the velocity is constant over period. Then averaged force over period is $$ \hat F_i = \frac{\omega}{2\pi} \int_t^{t+\frac{2\pi}{\omega}} F_i =  \frac{\omega}{2\pi} \int_t^{t+\frac{2\pi}{\omega}} f(v_i,r_i) =  \frac{\omega}{2\pi} \int_t^{t+\frac{2\pi}{\omega}} f\left( \frac{m_2\omega L}{m}\alpha \cos(\omega t),r_i\right) $$ But drag force always acts in opposite direction to the velocity and its magnitude does not depend on the direction. We have to get $$ \frac{\omega}{2\pi} \int_t^{t+\frac{2\pi}{\omega}} f\left( \frac{m_2\omega L}{m}\alpha \cos(\omega t),r_i\right) = 0 $$  Possible flaw in the calculation I assumed that the acceleration of the swimmer is much smaller than acceleration of individual spheres. Thus I could treat $v$ as constant in the integration.


Downloaded Ubuntu 12.04 to file copied to DVD disc, won't open on Win XP pro, asks for program to open it?

Tried IE to open 12.04 but it will not.  What to do? How do I open it?


Adding Arabic text to an English document

I'm trying to include Arabic text in an English document (I'm a new latex user), but I can't seem to get any Arabic text to render at all, using xelatex or any kind of tex. I'm using texshop 3.51 on a mac. I can't get this basic example to work, it just displays question marks in the output pdf.  \documentclass[12pt]{article} \usepackage[utf]{arabxetex} \newfontfamily\arabicfont[Script=Arabic]{Amiri} \begin{document} \begin{arab}[voc] وَهَذِهِ فِقرَةٌ بِالعَرَبِيَة مَعَ كَلِمَة اِنكلِيزِيَة \end{arab} \end{document}     I've downloaded Amiri (and also Scheherazade and Lateef) into Fontbook, and they show up if I go Source->Font->Show Fonts in texshop. If I remove the Amiri part it still doesn't work.   Is there anything I can do? I've looked at other links here, like  and  but I can't even render any of those examples.   Thank you so much for any help! I'll love you forever if I can get this to work.


What do you understand by this line "dr-- -w- --x file"

As far my assumption it is related to directory but after that i cannot understand the remaining pattern


How do I create a program that yields combinations of sums for a single integer?

In python, I want to have my program prompt me to 'Enter number:' and then I will do so. For example, I will enter '5' and in return I want it to find every combination of numbers between 1 and 5, including 1 and 5, that adds up to 5 without repeating any sequences or numbers. So the output of this should be the pairs 1,4 and 2,3. On top of that, I also want it to tell me how many outputs I have, so in this case 2. And I want to make sure that if I input a number higher, say 10, it will yield every combination even if it is larger than a pair, so it would yield 1,2,3,4 as one of the outputs and 1,9 as another, etc.


Does $|x|^p$ with $0<p<1$ satisfy the triangle inequality on $\mathbb{R}$?

I am curious about whether $|x|^p$ with $0<p<1$ satisfy $|x+y|^p\leq|x|^p+|y|^p$ for $x,y\in\mathbb{R}$.   So far my trials show that this seems to be right... So can anybody confirm whether this is right or wrong and give a proof or counterexample?


Disable opening browser from Windows Explorer Address Bar

How can i prevent Windows explorer from opening my internet browser when I mistype something in the address bar?  For example, I often type Alt+d, cmd to quickly select the address bar and open cmd.exe in the current directory.  However, I often mistype, and hit cdm instead of cmd.  This will open my default browser and search for cdm, and I deeply hate this.  Sure, it only takes a couple seconds to go back, but that doesn't keep me from hating it.  I'm not interested in making links of my commonly mis-typed programs (which I have actually done already), e.g. create a link of cdm.exe that points to cmd.exe.  I just want to turn this feature off, if possible.


Why am I getting NullPointerException when I'm not dereferencing anything that's pointing to Null?

int playerNum,cardNum; Cards card=null;           for(playerNum=0;playerNum<=NUMPLAYERS-1;playerNum++) {      //some code...                  for(cardNum=1;cardNum<=5;cardNum++)     {      card=( deckOfCards.deal() );       players[playerNum].setHand_1by1(card);//I get NullPointerException for using the method here                       //some code...                          } }   class Hand  {      private Cards[] hand=new Cards[5];      private int counter;            //no constructor, just a setter.      public void setHand_1by1(Cards card)      {          if(counter>=hand.length)          {              System.out.printf("Hand is full");          }          else          {              hand[counter]=card;              counter++;          }               } //some code... }  I understand that you get a NullPointerException when you try to dereference something that's pointing to nothing(ie null). 1)But card of Cards type is pointing to something due to the method deckOfCards.deal() so that's not the problem, must be something in the method. 2)In the setHand_1by1(), hand[counter] is of Cards type.  All I did was make it point to valid memory containing data of Cards type in the else block. Why am I then getting a NullPointerException error? Edit: Just showing how I created my players: Hand[] players=new Hand[NUMPLAYERS];


Hi I've stumbled into the administration of a Legacy SQL 2000 server that has had next to no maintenance for the past 8 years (and is very slow).  As I have only been doing DBA / PT for the past 2 years (I'm primarily a Developer) I don't have allot of experience on 2000.  Can anyone point me in the direction of some maintenance, tuning scripts.  Just figured I'd ask first before I reinvent the wheel for something I will rarely use.  Thanks Guys / Girls !


My Canon 350D is no longer raising the AF mirror when it takes a photo.  Instead, it looks like this when the mirror flips up.   This results in a photo that is half black due to the sensor being obscured.  This camera is 9 years old and has never been dropped, mishandled or subjected to harsh temperature or humidity.  Is there any common maintenance I can do to get this thing swinging properly again?


How do you revert or reinstall a configuration file in Debian/Ubuntu?  I accidentally overwrote the file /etc/bluetooth/main.conf. Running dpkg -S /etc/bluetooth/main.conf shows that the package bluez provides it, but when I run sudo apt-get install --reinstall bluez, it doesn't get reinstalled.


During kill Bill, we learn that all the black mamba had to do to get Hanzo to build her a sword, was to mention Bill's name.  When black mamba meets Bill at the end, she tells him that all she did was mention his name. Bill responds with, "that'll do it!"  So what was it that Bill did to Hanzo to make him come out of retirement and make another weapon of death?


How to implement policy conform systemd custom actions on Debian?

What do I mean by custom actions? Here are some examples.  sudo service apache2 stop-htcacheclean    sudo service apache2 graceful-stop sudo service apache2 start-htcacheclean sudo service apparmor recache   How can these be re-implemented when porting sysvinit scripts to systemd services?  The problem with systemd is, that differentiating daemon arguments cannot be conditionally used?  And how to do so while adhering with Debian policy?  Or do you know any example Debian systemd services that already support such custom/legacy actions?


function substr() returns me a character like ? in a rombus when I use it

I have a table in mysql called messages. I use the following code to call date from my table and print them.  <?php $message_query = mysql_query(" SELECT `messages_id`, `from_id`, `message`, `date` FROM `messages` WHERE `group_hash`='$hash' ORDER BY `date` ASC ");  while($run_message = mysql_fetch_array($message_query)){     $message = $run_message['message'];     $print_message = substr($message, 0, 100); }   echo "$print_message";   ?>   I use the function substr() to give me a certain number of characters of the message that will be displayed. Messages are writen in Greek language and stored in field message which has type = utf8_general_ci. Everything works fine and the message dispalyed correctly. The only problem is that when a word that is printed cutted off, I get at the end of the word a symbol like ? in a rombus. When the word that printed does not cutted off, I don't get it. Any idea how to fix this?


Determinant of a $2\times 2$ block matrix

I would like to know the proof for:  The determinant of the block matrix $$\begin{pmatrix} A & B\\ C& D\end{pmatrix}$$ equals $$(D-1) \det(A) + \det(A-BC) = (D+1) \det(A) - \det(A+BC)$$ when $A$ is a square matrix, $D$ is a scalar, $C$ is a row vector and $B$ is a column vector.  I appreciate your help.


Can two or more different models of Yongnuo flash work together?

I have a Yongnuo YN-568EX flash and I use it with a Nikon D7100.   If I buy another two more Yongnuo flashes of any model other than a YN-568EX, in principle will they all work together using at least one of the many types of setup?  If the answer is yes, does the same apply to different models from another brand? e.g. Could you use a Nikon SB-900 and SB-700 together off of the same camera?


Simplest way to integrate $\int \frac{1}{1+\tan x}dx,$

$$\int \frac{1}{1+\tan x}dx,$$  A substitution like $t = \tan x, \;dt = (1+t^2)dx$ etc. immediately comes to mind, but I find this method a bit lengthy with the partial fractions. Is there a more concise solution to this?


How to make \begin{align} counter start over again?

I did a first \begin{align} with equations in a document and I did a second one. Yet I noticed that the counter didn't started over again.  For instance here is the second equation which should start form one again.    Here is a code I hope that reproduce the problem but from which the photo is from.  \usepackage{amsmath}  \begin{document}  \begin{align} \neg\phi\rightarrow\Box\neg\phi,w_i \mbox{ contrapositive of }T\\ \neg\neg\phi\rightarrow\neg\Box\neg\phi,w_i \mbox{ negation of }1 \end{align}  blabla      \begin{align} &\neg(\Diamond\Diamond p\rightarrow\Box\Diamond p),w_i\mbox{ hypothesis}\\ &\Diamond\Diamond p,w_i\mbox{ from } R_{\neg}\mbox{ on }3\\ &\neg\Box\Diamond p,w_i\mbox{ from } R_{\neg}\mbox{ on }3\\ &\Diamond\neg\Diamond p,w_i\mbox{ from } R_{\neg\Box}\mbox{ on }5\\ &\Diamond\Box\neg p,w_i\mbox{ from } R_{\neg\Diamond}\mbox{ on }\\ &w_iRw_j\mbox{ from } R_{\Diamond}\mbox{ on }\\ &\Box\neg p,w_j\mbox{ from }R_{\Diamond}\mbox{ on }\\ &w_jRw_k\mbox{ from } R_{\Box}\mbox{ on }\\ &\neg p,w_k\mbox{ from } R_{\Box}\mbox{ on }\\ &w_iRw_j\mbox{ from } R_{\Diamond}\mbox{ on }4\\ &\Diamond p,w_j\mbox{ from }R_{\Diamond}\mbox{ on }4\\ &w_jRw_k\mbox{ from } R_{\Box}\mbox{ on }13\\ &p,w_k\mbox{ from }R_{\Diamond}\mbox{ on }13 \end{align}  \end{document}


I'm worried about Stack Overflow content licensing

Strongly related:   It appears that all the submitted content on Stack Overflow is licensed under the  (CC) license .  What I read from that, Stack Overflow owns all the content on the site. Everybody can use any code on SO as long as Stack Overflow is attributed.   This worries me for developing proprietary software, because now the app is not fully owned by my company anymore (and pieces are just licensed off SO). Our legal guys are probably not going to be happy with that.  If I were to ask questions about my open source project, this also implies I now need to put all my OS projects under the same license. I like BSD, and these two are not exactly compatible.  I'd like to see all the questions and answers be placed under the public domain. I feel most people on SO already treat it as such, especially the ones developing proprietary software. I think it's in everybodies interest to also make this very clear on the site.


How do you become 'stylish' enough to access Luminose stores: Pokemon X and Y?

So upon entering Luminose city, I immediate sought out the clothing store to look at what was offered in this city. I mean, c'mon, it's pokemon with customization? Nuts! But when I entered the store, my character was told she wasn't 'as stylish as she could be', and asked to visit other clothing stores in Luminose before returning. Any help on how to access this particular store?


Understanding last three columns of 1910 US Census?

The last three columns in the 1910 US Census (columns 30, 31 and 32) have four numbers in them. Column 30 is supposedly about survivors of the Union or Confederate army, 31 is if you’re blind and 32 is labeled deaf and dumb.   I found the directions for the 1910 census - but I find nothing that indicates why they filled in those columns with numbers.  My example is from Chicago 1910 - and the columns show "17-5-8-0"  I don't see a pattern at all on what the numbers mean.  Below is a graphic/example of these annotations, taken from a random page of the 1910 US census.


I'm a GIS software developer, I've been working predominantly with MapInfo over the last year or so but have now been tasked with assessing QGIS to see if we can perform the same tasks we've developed in MapInfo with QGIS. Or rather compare the performance of the 2. So I'm in the early stages of getting to know how QGIS works, and since I'm used to workspaces in MapInfo I'm trying to understand more about QGIS project files (.qgs).   I've had a scout around but I haven't been able to find any official .qgs documentation, or anything particularly useful elsewhere...does anyone know if this exists?


What is the replacement for the old "too localized" OT reason? Other?

I understand why the old "too localized" option was removed for OT posts closure reasons, but occasionally I still encounter posts that fall in this category.  For example, one recent questioner cited his professor's requirements and asked how he was supposed to write code to meet the requirements. Answering the question would have been valuable only to the students in that particular class, an obvious case of "too localized".  How are we supposed to flag such questions now? Use the "Other" category and just manually write in something like "This question will only help people in the student's class and is therefore too specific or localized for a general Q&A forum." In other words, writing out manually what used to be one of the choices?  Here is the actual question:


Is there any way I can obfuscate ".sh" shell script?

I'm running Ubuntu. I need to know any way to obfuscate .sh shell script file contents in order to make it very difficult to read.  Any suggestion are welcome, including using online obfuscator.


What is the next perfect square of the form 14444... in decimal notation?

We know that $12^2 = 144$ and that $38^2 = 1444$. Are there any other perfect squares in the form of $\frac{13}{9} (10^n - 1) + 1$ (i.e. $1$ followed by $n$ $4$'s), and how would we prove it?


Bionic: How can I automatically enable VPN on a network connection?

In Xenial 16.04, I was able to use Network Manager to configure a VPN to autostart per network connection.  In Bionic 18.04, I can't yet find this option.  Is it available via some configuration or additional package?  See also:  and


I have a custom list and I am using content types to add items to the list. I am using OOTB forms for new and edit items. One field that I see on the EditForm.aspx is the one that I hope I get on the NewForm.aspx also and it is the Content Type field. It is shown in the following screenshot. Do you know how to add that field on the NewForm.aspx page also?    Thanks.


Can I reinstall Windows 7 without touching my existing dual boot Ubuntu installation?

I have dual boot configured with Windows 7 (32bit) and Ubuntu 12.04(64bit). I installed Ubuntu after windows, now my windows is corrupt due to some virus and I need to reinstall it. Currently when I start my PC, grub loader comes up and I need to select Ubuntu or Windows.   I was wondering how can I install windows again and still have my Ubuntu install? Is there a way to do this?  I do not want to install Ubuntu again and lose my settings and data there.   Thanks, Ketan


PHP: How to detect how many time interval in minutes includes between two DateTime?

i have two DateTime  $datetime1 = date_create_from_format('H:i', '12:10'); $datetime2 = date_create_from_format('H:i', '18:16');   and i have interval in minutes, some for examlpe 56 minutes  How many times this interval includes between $datetime1 and $datetime2?  I try   $diff = $datetime1->diff($datetime2)   but object $diff do not include this information


I have a ul with the following elements:

Home

About Me

Work

Contact

Blog

   I'd like to reorder the Home element and place it in the middle in certain situations.  When viewing this in a smaller screen, the list will be rendered vertically, following the order specified in the markup.  However, when viewing on a larger screen, the list will be horizontal, and Home will be in the middle (between Work and Contact).  Is this possible to do purely in CSS? or will I need to use JS or JQuery to reorder the
 elements?


Automatically remove "inbox" label from messages with other labels

I created some filters to label my e-mails in Gmail, but all of these multiple label mails have the "inbox" label too!   How can I remove the inbox label on labeled emails? (With this configuration labeled e-mail will not show in inbox.)


Extreme learning machine: what's it all about?

I've been thinking about, implementing and using the Extreme Learning Machine (ELM) paradigm for more than a year now, and the longer I do, the more I doubt that it is really a good thing. My opinion, however, seems to be in contrast with scientific community where -- when using citations and new publications as a measure -- it seems to be a hot topic.  The ELM has been introduced by  around 2003. The underlying idea is rather simple: start with a 2-layer artificial neural network and randomly assign the coefficients in the first layer. This, one transforms the non-linear optimization problem which is usually handled via backpropagation into a simple linear regression problem. More detailed, for $\mathbf x \in \mathbb R^D$, the model is  $$ f(\mathbf x) = \sum_{i=1}^{N_\text{hidden}} w_i  \, \sigma\left(v_{i0} + \sum_{k=1}^{D} v_{ik} x_k \right)\,.$$  Now, only the $w_i$ are adjusted (in order to minimize squared-error-loss), whereas the $v_{ik}$'s are all chosen randomly. As a compensation for the loss in degrees-of-freedom, the usual suggestion is to use a rather large number of hidden nodes (i.e. free parameters $w_i$).  From another perspective (not the one usually promoted in the literature, which comes from the neural network side), the whole procedure is simply linear regression, but one where you choose your basis functions $\phi$ randomly, for example  $$ \phi_i(\mathbf x) = \sigma\left(v_{i0} + \sum_{k=1}^{D} v_{ik} x_k \right)\,.$$  (Many other choices beside the sigmoid are possible for the random functions. For instance, the same principle has also been applied using radial basis functions.)  From this viewpoint, the whole method becomes almost too simplistic, and this is also the point where I start to doubt that the method is really a good one (... whereas its scientific marketing certainly is). So, here are my questions:   The idea to raster the input space using random basis functions is, in my opinion, good for low dimensions. In high dimensions, I think it is just not possible to find a good choice using random selection with a reasonable number of basisfunctions. Therefore, does the ELM degrade in high-dimensions (due to the curse of dimensionality)? Do you know of experimental results supporting/contradicting this opinion? In the linked paper there is only one 27-dimensional regression data set (PYRIM) where the method performs similar to SVMs (whereas I would rather like to see a comparison to a backpropagation ANN) More generally, I would like to here your comments about the ELM method.


Let $M$ be a manifold of dimension $n$ such that there exist two   charts $(U_a,\phi_a)$ and $(U_b,\phi_b)$ such that $U_a,U_b$ are   connected and $U_a\cap U_b\ne\emptyset$. Moreover the transition   function $\phi_{ab}$ neither preserves the orientation nor reverses the orientation. I have to show that $M$ is not orientable.   A manifold is orientable if it admits an oriented atlas, i.e. an atlas in which all the transition functions have Jacobian with positive determinant.


How do I count all the lines of code in all headers and source files in a folder? *.cpp *.h

Say I have a project folder containing a number of header and source files for c++; How would I count the total number of lines of all of these?


I have a very high-dimensional dataset with 27k features. I want to a reduce the dimensionality of the dataset. I want to use PCA to reduce the dimensionality to 2 as the toolbox I am using expects 2 dimensions.  But When I am trying to apply PCA in Matlab I am getting an out of memory error. Can I apply PCA twice to get down to 2 dimesions, i.e. 27k -> intermediate -> 2 dimensions?


How can I prevent applications from running on startup?

Possible Duplicate:          I've installed some applications that I mostly like, except for the fact that they all decided they were too important not to auto-start.  None of them give me any option within the application to disable the auto-start "feature."  Can I stop these applications from auto-starting?  And if so, how?  Note: My phone is not rooted, so I'm especially interested in solutions that do not require a rooted device, but all answers are welcome, even if they require rooting the device, since I may do this eventually.  Also note: I'd prefer not to fiddle around with clumsy auto-kill features in task-killer programs, as I've found them to be incredibly unreliable on my phone (Motorola Milestone/Droid).


List files in a specific folder in a document library

I there anyway to output the files of a specific folder in a document library?  Listing them will be like   foreach $file in $folder.files {     write-host $file.name }    But how do I tell it to look a specific folder? In CSOM please Tried the below answer but it did not work