Should we make the Red Baron hat trigger a permanent badge?

During Winterbash 2014, there was a hat called , which was earned by giving an answer scoring 5 or better to question that had a score of −3 or worse at the time of answering and later rose to a score of +3 or better.  I’ve already shared the . Those cases give me a great deal of confidence that this would be a challenging badge trigger that would produce good behavior with a minor tweak. Here are the Red Barons earned on other sites:    (Logan Maingi) Mathematics  (Mike Miller) Mathematics  (Hugo) English Language and Usage  (tchrist) English Language and Usage  (Mr. Shiny and New 安宇) English Language and Usage  (Darth Satan) Science Fiction and Fantasy  (DVK) Science Fiction and Fantasy  (rolfl) Code Review  (Heslacher and Hosch250) Code Review  (Edward) Code Review  (janos and Manny Meng) Code Review  (Mark Mayo, Rory Alsop and MeNoTalk) Travel      (DJClayworth) Christianity  (McMagister) Puzzling   Looking through the timelines, I’m convinced that the answerer’s votes should be excluded from the pre-answer question score calculation. Doing that would have reduced the number of Red Barons to 16 across the network. However, the cost of making a badge harder to obtain is worth the benefit of avoiding giving people an incentive to manipulate question scores¹.  To wrap up, the hat seemed to have encouraged a number of great answers and rescued some questions that would otherwise have been lost to time. My outstanding questions are:   Were there any problems on questions where people were attempting to earn the hat, but failed? (Or any other problems I didn’t observe.) If not, should we  or create a new badge? If we create a new badge, what should it be called?   I’m especially interested in feedback that counters my own bias in favor of this idea. If I’m missing any problems, I’d like to know about them now.    ¹ Several questions were downvoted, answered, edited (sometimes trivially)  and upvoted by the user who earned the hat.


I'm using 2x4 Gb sticks (1866 Mhz) (4 DDMI slots on motherboard, max 32 Gb). I accidentally bought a 8 Gb stick of the same type (instead of 2x4 Gb) . How should I set up this version of 16 Gb Rams for best performance? (I will buy another 8 gb stick to match it in the future).  Thank you in regards


Difference between field and wavefunction

Can someone give me a clear explanation of what is the difference between a classical field, a wave function of a particle and a quantum field? I haven't find a clear explanation. For example for Klein-Gordon equation, the solution $\phi(x)$ is a plane wave, but $\phi(x)$ can be interpreted in any of the 3 ways I mentioned above and I am not sure what is the difference between them. (for example I am not sure why the wave function is not a field, as it assigns to any point in space a value, so it seems to behave like a field). Thank you!


How to share partition between Windows and Ubuntu?

I'm getting a PC with Windows and I want to dual boot using Ubuntu as my primary OS.  I want to create a Home partition to store all my files and hopefully be able to access them on Windows 7 without having to manually mount the partition or anything.  I want to know what kind of partition should I create and if I can share my Home partition to simplify matters.  Thanks


How can I disable suspend during download, but the screen will still shut down?

I'm on Ubuntu Gnome 15.10.  I am regularly downloading large files (~800 MB), but I have a very slow Internet connection. It usually take a relatively long time to download it.  Since I am not continuously working on the laptop, it automatically goes into sleep/hibernation mode.   When I press any key after it has gone to sleep/hibernation mode, it wakes up and takes me to the login screen.   I was able to find the power settings, which gave surprisingly few options:    However, I am unsure about a couple of things      Is there a way in which my computer does not suspend during downloads, but my screen is still shut off when I am not working on it during download? Are there settings to be made to achieve this, or other solutions?


jQuery - how to validate a date of birth using jQuery Validation plugin?

I want to validate an input ( date of birth ) using jQuery Validation plugin, but it must be in format "dd/mm/yyyy" and also not validate when the date of year is over 2002.   So the date is valid when it's in this format "dd/mm/yyyy" and year over "2002"


How can I move the start menu / task bar to a secondary display?

I have a netbook using Windows XP, with a secondary monitor attached. Both monitors are configured and working correctly.  What I would like to do is  move the start menu and the task bar over to the secondary display (monitor number 2). I can't find any obvious means of doing this. Is it possible, if so, how can I do it?


Is there a method to check if a container needs scrollbars?

Is there a method to check if a container needs scrollbars possibly without adding an object to the container?   Alternatively is there a method to tell if scaled content extends past it's container?   Update: It looks like there is a element.scrollTopMax and element.scrollLeftMax. That might be non zero after an element is larger than the container.


Let $G_1,\dots,G_n$ be groups. Prove that the direct product $G_1\times\cdots\times G_n$ is abelian if, and only if, each of $G_1,\dots,G_n$ is abelian. To prove that the direct product is abelian is straightforward but what I don't understand is the converse.


Faster growing function than the fast growing heiarchy under Church-Kleene?

Is there a computable function that grows faster than any function in a fast growing hierarchy with index less than the Church–Kleene ordinal, where computable fundamental sequences are used?  If the answer is negative, is there any proof that can be referenced or provided?  Fast growing heiarchies are defined on their wiki page, .  As discussed in the comments, I do not think the particular fundamental sequences chosen will affect this question. If I am wrong on that point, please let me know.


I would like to increase the depth of my table of contents in the following (or a similar) way:   Part I  Chapter 1  A.  1.  1.1  1.1.1  1.1.1.1  B.  2.  2.1  ... and so on.  How could I do that? Thanks.


Command to get the hostname of remote server using IP address

I want to get the hostname of a remote server using the IP address using my Ubuntu.  In Windows we can get using NBTSTAT but this doesn't work in Linux.  Does anyone know how to do that?


I am using Ubuntu 14.04 LTS. Now I am unable to make calls on Skype. Every time it shows call failed. How can I rectify the error?


What benefits does the 64-bit version of Notepad++ have over the 32-bit version?

Notepad++ is available in a 64-bit version in addition to a 32-bit version.  What benefits does the 64-bit version of Notepad++ have over the 32-bit version when running in Windows 7?  What about in Windows 10?  I imagine one of the benefits is being able to load enormous, multi-gigabyte files.  Is that correct?  Are there other benefits?    EDIT 1: There seemed to be much interest in the release of a 64-bit version of Notepad++, but it's hard to imagine that so many people are using it to edit files over 4GB in size, even if multiple files are open.  That made me wonder "What are all the advantages to the 64-bit version of Notepad++?".  EDIT 2: I don't think this is a duplicate of  because I'm asking about specific benefits for this particular application.  What makes this case even more curious is that, it's probably safe to say that a majority people don't need to edit more than 4GB of text at a time, and that the 64-bit version of Notepad++ has a major limitation (fewer plugins).


Should "from" or "of" be used in the following?     The shoes are made from/of rubber tires.   I'd appreciate your help.


How to solve 'I found no database files--while read file something.aux'

Hi I am trying to include references into my paper but it keeps showing the following when I compile. I am using texstudio. Message: I'm skipping whatever remains of this command The style file: plain.bst I found no database files---while reading file term paper.aux Warning--I didn't find a database entry for "Astrov"  My code is like this:   \documentclass[letter,scriptaddress,twocolumn, prl,showkeys]{revtex4}  \usepackage{amssymb, amsmath, amstext, amscd, verbatim, mathtools, graphicx, float, caption, subcaption} \usepackage[utf8]{inputenc} \usepackage{natbib} \begin{document} This is my reference\cite[1]{Astrov}. \bibliography{term paper} \bibliographystyle{plain} \end{document}   They are all in the same directory. I am really panicing about this at the moment and apologize if similar questions have been asked before. Thanks in advance for your help!


Today in calc we learned these three identities: $$\int{\frac{du}{\sqrt{a^2-u^2}}} =  \arcsin{\frac{u}{a}}+C$$ $$\int{\frac{du}{a^2+u^2}} =  \frac{1}{a}\arctan{\frac{u}{a}}+C$$ $$\int{\frac{du}{u\sqrt{u^2-a^2}}} =  \frac{1}{a}\arctan{\frac{|u|}{a}}+C$$  These identities are too complex for me to derive myself. I found it curious that the arcsine one was the only one without $\frac{1}{a}$. What's the reason for this?


Could someone provide a wrong clime and  its wrong proof by induction so that only the first step be wrong?


Why java script increases the number precision when a number added in lool

I found this strange behavior while adding a number, javascript increases the number precision, because of this I have to round the number to one decimal place. Why is this so   var n = 1; do {   n = n + 0.2;   console.log(n) } while (n < 100)


Editing existing answer vs. adding a new answer

Once you add an answer to a question, there is always the option to add another answer. What would be the purpose of adding a new second answer versus just editing your original answer?


Is virtual destructor in base class needed when all destructors are default

I understand that we should use virtual destructors in base classes to ensure proper resource disposal, because it guarantees the inheritance chain will be observed and all parent destructors will be called when destructing an object. That being said, do we also need virtual destructors in base classes when both the base class and any subclasses use only the default destructor? Example:  class Printable {   virtual std::string print(); };  class A : public Printable {   int foo;   bool bar;   std::string print() override; }  class B : public Printable {   std::vector<int> foo;   std::string print() override; }   There are no resources being managed, and all destructors are implicitly default. Is it still advisable to specify a virtual destructor in Printable?


Choosing whether to include PDF or PNG in PDFLaTeX

Can I tell graphicx somehow which graphic format to choose when I omit the file extension in includegraphics and both a PDF and a PNG version of the same image exist? The reason is that I have some very large PDF vector graphics (in terms of file size/drawing primitives) that take a pretty long time to load each time I view the document. I would like to convert them to PNGs while working on the document and only use the PDF versions in the final document. Therefore, a global option that I can switch in the end would be great.  An additional plus would be to do the conversion to PNG on the fly during the LaTeX run if there is a PDF that has not been converted to PNG yet, if a tool for that exists. (I know how to use convert, but not how to include it automatically in LaTeX.)


Constructor invocation bound to new keyword in Java?

I'm working on Java Code Profiling where I need to know how many times a method has invoked a constructor in source code. So far the easiest way is to scan for new keyword and count that how many times constructor has been invoked. I would like to know is there any possibility where a constructor can be invoked without the new keyword?  Also if I'm only scanning for new keyword and binding it with constructor invocation only, it is possible that new keyword can also be used for some other purpose besides constructor invocation? (in that case my constructor invocation count could be wrong if such statement occurs in code)   Edit: I want to increase the count when any constructor is called.


Is it appropriate to browse through a user's old questions / answers and vote on some of them?

The following question might be a duplicate of . If so, feel free to close it. But I ask because it's not clear to me whether it's a duplicate question or not. Sometimes I see a question or answer by a user which I like so much, I wander over to the user's page and scroll through their other questions / answers to see what else they've written. I click on the ones that look interesting and read them, and from time to time I upvote or (more rarely) downvote a question / answer which I find deserving. In practice, it's unusual for me to vote on more than 2-3 questions / answers from a single user in a session of doing this. Once I've visited a user's page in this way, it's unlikely that I'll ever return to their user page, and especially unlikely that I'll return to their page within the next few months. The intention of the whole business is not to give the user "extra rep", subverting the bounty system, nor to punish the user with spurious downvotes, but simply to expose myself to some of a good user's work on Stack Exchange. Now, I'm pretty sure that this behavior is  entirely  borderline appropriate on any Stack Exchange site. That is, there's some line between the kind of behavior I've described and vote manipulation, and I'm pretty sure that what I've described is  well  on the acceptable side. I imagine the actual threshold for vote manipulation is  well  slightly above the level of voting I've described. Question: Is there anything else to be said about the kind of behavior I've described in the context of avoiding vote manipulation? I understand that the voting fraud detection system never automatically punishes a user beyond reversing inappropriate votes -- any punishment for voting fraud is manual and would presumably only come about if there were a repeated problem, with ample warning and clarification on what's appropriate. I also understand the value in not being too precise publicly about what counts as "appropriate" and what doesn't to avoid the scenario of somebody trying to game the system and fly just barely under the radar in a vote manipulation campaign. So I'm perfectly happy with the answer to my question being "No, just use your best judgment and don't be stupid; if it ever becomes a problem we'll talk about it then". I just thought I'd ask in case there is more to be said.


Can magic be used to transform a muggle into a witch/wizard? (HP universe)

Could a very accomplished witch/wizard cast any number of spells or charms to give a muggle some amount of magical powers? Could it be even theoretically possible?


Filling grouped object background with color in Illustrator

Is there any way to fill grouped objects background in Illustrator?  Below is example how i want it, right now i simply just put white square behind them.


This morning i found movies inside my server (debian VPS, apache,webmin/virtualmin), files are located in /var/log/roundcube/./ and the user/group is www-data  I looked in my log (apache,proftp,auth) and i didn t found weird lines. rkhunter found nothing bad.  how can i check the history of a file (in hidden folder) or the way that the user uploaded movies in this folder.  i guess it s a backdoor but when i scan my website i found nothing bad.  i think i ll cut my website for a while and see if there is new movies in folder, if yes it means that the user have ftp/ssh access or that the backdoor is not in my var/www/  Thanks by advance


number of non-zero, distinct, eigen values

Let $V^T$ denote the transpose of a vector $V$. Consider two non-zero $p$-dimensional column vectors $a$ and $b$, for $p\ge 2$.  How many non-zero distinct eigen-values does the $p\times p$ matrix $ab^T + b a^T$ have?


do i require transist visa while travelling to USA from manchester terminal 2

I am travelling from mumbai to houston via manchester so uk visa is required if the terminal is same?


How do I connect another computer with only an ethernet cable?

I would like to connect another computer to my Ubuntu 16.04 LTS laptop and share its internet connection.  How do I do set this up?


Finding a generating function for the set of all integer partitions

I know that integers can be partitioned into the different ways to get that integer. For example:   $$4 = 3+1 = 2+2 = 2+1+1 = 1+1+1+1$$  can be written as   $$(4),(3, 1),(2, 2),(2, 1, 1),  (1, 1, 1, 1)$$  We can then define the size of a partition  $$λ = (λ_1, \ldots, λ_k)$$  to be  $$\sum λ_i$$ (so partitions of $n$ have size $n$)  How can I find a generating function for the set of all integer partitions?


Counter-example: If $U \subseteq X$ is open and we have a S.E.S of Abelian sheaves, the corresponding S.E.S of rings/modules may not be exact

I'm looking for a counter-example for the problem in title when $F_1$ is not flabby. We know that if $0\to F_1 \to F_2 \to F_3\to 0$ is a short exact sequence of Abelian sheaves and $F_1$ is flabby then for any $U \subseteq X$ which is open we have the following exact sequence: $$0\to F_1(U) \to F_2(U) \to F_3(U)\to 0$$  Is there a counter-example that shows this may no longer be true if $F_1$ is not flabby? If yes, how a counter-example can be constructed?  Edit: I'm looking for a solution without reference to manifolds or De Rham cohomology. Thanks.


How do I delete all lines in a file until it matches a string line pattern?

How can I delete lines in a file until it matches a string line pattern?  cat test.txt The first line The second line The third line The fourth line pen test/ut The sixth line The seventh line   I would like to use shell/python script to remove all the lines from the above file until it matches the file string pattern "pen test"  Expected output: The file "test.txt" should have only these lines after removing above lines:  The sixth line The seventh line


How to make everything bold in math mode?

I want to write everything in math mode as bold characters. I know that with bm package I can do that. Here is my example code.  \documentclass{article} \usepackage{bm,amsmath}  \begin{document} $E = \frac{1}{2} mv^2$. \newline \begin{equation} E =mc^2 \end{equation} \begin{align} \tan x = \frac{\sin x}{\cos x}  \end{align}   \hrule % I don't want to use \bm{} everytime. $\bm{E = \frac{1}{2} mv^2}$. \newline \begin{equation} \bm{E =mc^2} \end{equation} \begin{align} \bm{\tan x = \frac{\sin x}{\cos x}}  \end{align}  \end{document}   I don't want to write \bm{} for every mathematical expression. I want bold characters whenever I write any mathematical expression inside $$ or \begin{equation}...\end{equation}. Is there any way around?


We were taught that $[a,a]=\{a\}$ and $(a,a)=\emptyset $, For $a \in \Bbb R$.  So I wonder what will be the result in the case $(a,a]$?  Let $A=(a,a]$.  Then $a \in A$ and $a \notin A$.  This is absurd. So I guess $A$ is undefined.


I try to use a WFS service with OpenStreetMap to request GeoServer GeoJSON file. First I had a error message on the Firefox Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at http://localhost:8080/geoserver/robot/ows?service=WFS&version=1.0.0&request=GetFeature&typeName=robot:geofield&outputFormat=aoolication%2Fjson. (Reason: CORS header 'Access-Control-Allow-Origin' missing).  Then I pasted the following lines in the web.xml from /usr/share/geoserver/webapps/geoserver/WEB-INF  <filter>   <filter-name>CorsFilter</filter-name>   <filter-class>org.apache.catalina.filters.CorsFilter</filter-class>   <init-param>     <param-name>cors.allowed.origins</param-name>     <param-value>*</param-value>   </init-param> </filter> <filter-mapping>   <filter-name>CorsFilter</filter-name>   <url-pattern>/*</url-pattern> </filter-mapping>   After when I go on  I have a HTTP ERROR: 503 and still have the same CORS header problem   I don't know what is wrong, maybe this method doesn't work with latest GeoServer versions    If someone has a good and clear answer, it will be great because I think I'm not the only one who want to use a wfs with GeoServer and OpenLayers.


How to prevent a numbered list when starting a paragraph with "1."?

I just stumbled upon  on Chess Stack Exchange, where it looks like the author wanted to start a paragraph with "1. Nxc6" (which is the common notation for a chess move) but did not want a numbered list to appear, which automatically happens if you start a paragraph with a number followed by a dot, like this:   Nxc6 gets the two Bishops in a position     I was able to solve it by introducing an HTML comment like this:  <!--> 1. Nxc6 gets the two Bishops in a position   which produces   1. Nxc6 gets the two Bishops in a position  but I feel this is a rather inelegant solution. Are there any other/better options, preferably within pure Markdown?


Short way to run command if variable is set

This is a hack I just discovered:  DEBUG=true $DEBUG && echo "Hello"   And this just happens to work because true is an actual command which returns 0, and the && operator is happy with that:  » true » echo $? 0   Is there a non-hackish way of execute a piece of code if a variable is set, to whatever value, except the empty string? Something like this, but as a readable one-liner (like the one above):  myvar="ggg" if [ "$myvar" != "" ] ; then echo "Hello" ; fi


Rep gain indicator is empty if it is none rep gain and it is confusing

It is  profile   It happens when (for example) question is down voted 5 times and up voted 2 times (+10/-10), or an answer upvoted 1 time and downvoted 5 times -  title doesn't disappear from these recent rep changes.


biblatex and biber incompatible? [Texlive+Texstudio]

So I'm writing a report and changed my OS a while back and had to reinstall latex. I used the texlive installer for linux. I am user biber for my bibliography and this used to work, I now however get this error;  ERROR - Error: Found biblatex control file version 3.0, expected version 3.5. This means that your biber (2.12) and biblatex () versions are incompatible. See compat matrix in biblatex or biber PDF documentation.   I cannot figure out how to down/upgrade the package correctly. Texlive is completely up to date (biblatex 3.12) + (biber 2.12). There's no obvious downgrading option with tlmgr, how do I fix this?  Edit1;  In the compatibility matrix it tells me 2.12 and 3.12 should work together... What's the issue here?  Edit2;  Sorry I am a total derp, I was removing the wrong .aux/.bcf etc files from another project which is almost identical. That's what I get for not having my morning coffee I suppose...


With a WMS server Url, how to know it is a Web map service or a Web map tile service?

I need to add wms map in my project, and the url of wms server will be provided by users.   Are there any ways to know the type of server (wms or wmts) with the url proposed by users ? Or to know that the server supports tiles or not ?  I want to know this because in Openlayers3, there are two functions to getMap: ol.source.ImageWMS and ol.source.TileWMS. I think I need to know the type of server before calling the right function ol3.


Adjusting object keys after deleting key

In Javascript, I have an array of objects like so:  var array = [{ foo: 'bar' }, { foo: 'baz' }, { foo: 'qux' }];   which looks like this, really...  [0: {...}, 1: {...}, 2: {...}]   and I delete the second one:  delete array[1];   then I have this:  [0: {...}, 2: {...}]   How can I adjust this array so the keys are back in numerical order?


What are the axes of a t-SNE scatterplot?

What do the values in the x axis and y axis of this scatterplot correspond to? It is related to t-SNE but I don't know how.      The plot is from:     Lingren T, Chen P, Bochenek J, Doshi-Velez F, Manning-Courtney P, Bickel J, et al. (2016) . PLoS ONE 11(7): e0159621. doi:10.1371/journal.pone.0159621


"To do this" or "For doing this" to start explaining something?

Many questions have been asked and answered about "to + bare infinitive" vs "for + gerund" in the middle of a sentence.  However, when one wants to start explaining something, what is better? For instance:  "Now, let us focus on baking the bread.   To do this, start by turning the oven on.", or For doing this, start by turning the oven on."?   Are there even better expressions? I have not found anything concerning this situation, and I feel that the answers about the same problem but in the middle of a sentence do not apply here.


how do I mount the hard disk with Windows on it?

I am a user of Fedora 30. I installed Fedora on a USB memory stick and use it with Windows 10 on the same computer. How do I set the options in fstab to make it read-write to an NTFS-formatted Windows 10(hdd 01) or secondary disk(hdd 02)?


What did Auggie's father give to his wife in the movie Wonder?

There is a scene roughly in the last third of Wonder where Auggie's parents Nate and Isabel (Owen Wilson and Julia Roberts) spend an evening together while the kids are out. Nate has a surprise gift for his wife. She opens the box just enough to see it, laughs, and closes it again. So I asked myself the question:  What's in the box?


Example:  $query = $connection->query("SELECT `password` FROM `users` WHERE `userID` = ".$_SESSION['user'].";") or die("error in the query"); if (mysql_num_rows($query) < 1) {     die("Error: no such user"); } while ($row = $query->fetch_assoc()) {     if ($row['password'] != $_SESSION['pass']) {         die("Error: incorrect password");     } }   The above code is my only protection in a PHP script. Is there anything else that can make it more secure? I know that the $_SESSION array can not be changed on the client side. So in my opinion it should be enough. The session is controlled by WordPress.


How can I properly escape a string to be passed to a shell with a command argument

How can I properly escape arbitrary commands?     For example:  sudo -u chris sh -c 'echo "\"leftright\""'   The above echos:    "leftright"   How would I echo out:    "left'right"   I've tried the following which I would expect to work but does not:   sudo -u chris sh -c 'echo "\"left\'right\""'   I can't quite get my head round how it is parsed.


I'm trying to find the primitive elements of $GF(8),$ the minimal polynomials of all elements of $GF(8)$ and their roots, and calculate the powers of $\alpha^i$ for $x^3 + x + 1.$   If I did my math correct, I found the minimal polynomials to be $x, x + 1, x^3 + x + 1,$ and $x^3 + x^2 + 1,$ and the primitive elements to be $\alpha, \dots, \alpha^6 $  Would the powers of $\alpha^i$ as a polynomial (of degree at most two) be: $\alpha, \alpha^2, \alpha+ 1, \alpha^2 + \alpha, \alpha^2 + \alpha + 1,$ and $\alpha^2 + 1$?  Am I on the right track?


The problem is stated as:  "Find  $\lim_{x \to a} \frac{x^n - a^n}{x - a}$ for some parameter $a \in \mathbb{R}$. (Hint: Do you recognize this limit? If not, you can always simplify the fraction using long division.)"  But to be honest, I really don't know how to tackle this problem and the hint doesn't ring a bell. Normally I would try to make an attempt similar to the following example:   $\lim_{x \to -\infty} \frac{x^3 + 2x^2 + 2}{3x^3 + x + 4} \approx \lim_{x \to - \infty} \frac{x^3}{3x^3} = \frac{1}{3}$  Looking at the degree of the numerator and the denominator, comparing them and cutting off the uninteresting parts, but that approach doesn't seem to fit here.  Any suggestions?  Update:  I tried to rewrite the given answer in a different way which is more accessible to my way of thinking:  \begin{align} \frac{x^n - a^n}{x - a} &= (x-a) \sum_{k=1}^{n}a^{k-1}x^{n-k}\\ \lim_{x \to a} \frac{x^n - a^n}{x - a} &= \lim_{x \to a} \frac{(x-a) \sum_{k=1}^{n}a^{k-1}x^{n-k}}{x - a}\\  &= \lim_{x \to a} \sum_{k=1}^{n}a^{k-1}x^{n-k}\\ &= \sum_{k=1}^{n}a^{k-1}a^{n-k}\\ &= \sum_{k=1}^{n}a^{k-1+n-k}\\ &= \sum_{k=1}^{n}a^{n-1}\\ &= na^{n-1} \end{align}


How to install a LibreOffice Language Tools (Spelling Check, Thesaurus...)

What are the steps to install the Spelling Check and other language supports for LibreOffice. For example spanish, french, italian, etc..


How do I get the Nautilus link/icon to show in file manager in Ubuntu 18.04.1?

I recently updated to Ubuntu 18.04.1. Nautilus file manager has no Nautilus shell icon to allow me to access root files as in the attached pic from . How do I get the Nautilus shell icon, or link, on Nautilus file manager?


Renaming the bibliography page using BibTeX

Is there a way to rename (or do away with the name of) the bibliography page that is output using BibTeX?  If so, is the name dependent on the bibliographystyle, or is it something inherent within the BibTeX functionality?


If D is an Integral Domain and has finite characteristic p, prove p is prime.

So the question is simply.      If $D$ is an integral domain and has finite characteristic prove that the characteristic of $D$ is a prime number.    This is my proof.  Assume $p$ is the characteristic of $D$. Let $a$ be a non zero element of $D$. Seeking a contradiction assume $p$ is not prime.  Then $p$ can be written as a factor: $rs=p$ for some $r$ and some $s$. By definition $pa=0$, so $(rs)a=0$. We know that $r,s$ are non-zero, so by definition of integral domain the only way this equation can equal zero is if $a=0$ however this is a contradiction as we chose a to be a non-zero element of $D$. Therefore $p$ is a prime.   Is this proof correct? The answer I have for this problem is slightly longer and I thought I might have missed something in my proof.


JavaScript is not reading my file to alert, undefined when printing to console

Why won't this read my file!? What am I missing  NOTE - I also get warning : XMLHttpRequest on the main thread is deprecated because - not sure what else to use?    <script> function readTextFile(file)        {            var rawFile = new XMLHttpRequest();            rawFile.open("GET", file, true);            rawFile.onload= function (){                if(rawFile.readyState === 4)                {                    if(rawFile.status === 200 || rawFile.status == 0)                    {                        var allText = rawFile.responseText;alert(allText);                        console.log(alltext);                    }                     }            }         }         var test = readTextFile("file:///C:/Users/.../Desktop/***.txt")         console.log("test"+ test); //undefined </script>


How can I sort a key within the dictionaries into descending order?

I am very new to python and I would like to sort all the maximum scores into descending order. (There is a dictionary that stores the data for each student) At the moment it only prints the maximum scores of each student in the order the data is entered:   Maximum score Adam Watts 7 Henry Lloyd 10 Lucy Smith 9      This is the code I am using:  print("Maximum score") for key in keys:     print(key, max(Classes[key]))


alias for a command using !! to recall the last command

This is a follow-up question to        If you want to redo the same command with sudo !! after doing a command like this:  echo "something">/path/file   You can use the global replace syntax to recall the command:  !!:gs/>/|sudo tee -a /   Use a space after the -a parameter.  This is the equivalent to sudo !! but helps you bypass sudo restrictions for the < and >. Because sudo does not allow you to use [<, >].  How can I put this into an alias on my .bashrc so I can use it simple?  I tried  alias redo='!!:gs/>/|sudo tee -a /'   But this doesn't work, I get the error:  $ echo "sdfdsf">/path/file bash: /path/file: no permissions  $ redo bash: /: Is a directory tee: /: Is a directory


I have an array of Button objects that I want to pass a function with different arguments into.  This function takes an int argument.  I've tried the following:  public void ButtonClick(int i){   //do things with value of i }  public void FillButtonClicks(){   for(int i = 0; i < 3; i++){     ButtonArray[i].AddListener(delegate{ButtonClick(i);});   } }   This "works" in that the buttons receive the appropriate delegates, but it does NOT work in that the garbage collector is holding onto the value of 'i' in the for loop, i.e., when I click any of the three buttons, they all execute ButtonClick(3).  Is there a way to enforce the passing of values, or do I have to just do something dumb like:  ButtonArray[0].AddListener(delegate{ButtonClick(0);});     ButtonArray[1].AddListener(delegate{ButtonClick(1);});     ButtonArray[2].AddListener(delegate{ButtonClick(2);});


Grad school - Is transferring to another school for a Master's program (Computer Science) a good option?

I am an international student in the US (important as my stay in US is tied to my student visa, issued to attend my current university).  I joined as a grad student in the MS CS program in one of the okayish public universities (ranked ~50 on QS/US news). I joined in Fall '18 and am still in my first semester. I took all the so-called "difficult" courses, but I find them very trivial (considering my undergrad was from a very good university). I am very disappointed with the curriculum and feel the coursework is not at all rigorous for a grad-school.  I might sound super arrogant, but I feel out-of-place when I talk to other students and hear them cringe about how hard the courses are, or how they don't have enough time to finish assignments within the deadlines as I find all of the coursework very trivial and feel that the assignments are a joke.   Fortunately, I am working with one of the best profs the university has to offer on a very impactful project and the research is going great. But that's the only plus point I see from sticking around.  My aim from grad school is to get research experience and join one of the Big 4s or upcoming CS unicorn startups. I cannot see myself joining one of the Big-Ns after graduating since the students from this school rarely bag a Google/Fb/unicorn startup job.  Since December is the Fall'19 admissions deadline, I am thinking about reapplying to those top 10 CS schools which I couldn't get into last year (probably because of my poor undergrad GPA).   On the other hand, since every CS company just asks leetcode-style questions in interviews, I can just be super good at it and try to nail whatever interview I get without wasting another year and then doing the same.  I'm not really interested in any kind of credit transfer either since I would like to start fresh in a more rigorous curriculum.  I'm not sure if switching schools would be a wise decision and could really use some advice from the community here.  PS :  Probably related -   Posting with a dummy account for anonymity.


Show table structure and list of tables in PostgreSQL

I had employed MySQL for a couple of former projects. But now have  decided to switch to PostgreSQL. Not that version 8 also works on that,  ahem other OS which I'm stuck with at work.  But alas, two of the most useful commands appear to be missing:   SHOW TABLES DESCRIBE table   Inasmuch as my prototyping DB is on my NetBSD server at home while my  data waiting to be 'based is at work, such that I have to connect via  Perl/DBI and XML-RPC (not psql, alas). The IT dept here just says, "Use  MS-Access", so no help there.  While I'm in the initial stage I need an informative way to blunder  around and see what's what as I try different ways to build this thing.  For that I had always relied on the two above from MySQL.  I can't believe there is no way for PostgreSQL to tell me what the  current DB's table structure is via simple SQL queries executed remotely.  Surely there must be. But I can't seem to find out from the couple of  books I have. All I dug up was some ultra-lame hack to get column names  for an already known table name by doing a "WHERE 1 != 1" or some such  so that no actual rows could be returned. Not very informative, that.  Surely I've missed the point, somewhere.  So enlighten me, please. What, pray tell, are the PostgreSQL-ish SQL  queries one uses so as to explore a given DB's table structure? What is  the PostgreSQL translation for "SHOW TABLES" and "DESCRIBE table"?


PHP fwrite to csv file utf-8 not working

Can you plese help me with php fwrite. Csv showing wrong characters  something like:  opÄ‡ĹˇpĹˇÄ‡ĹˇÄ‡Ĺˇp Ä‡pĹˇÄ‡pĹˇÄ‡p ĹˇÄ‡pĹˇÄ‡pĹˇÄ‡  This is php code for input:  I can't find option to fix UTF-8 for this php:     <?php if (isset($_POST['myname'])){ $name = $_POST['myname']; $handle = fopen('names.csv', 'a'); fwrite($handle, $name."\n"); fclose($handle); }  ?>   Html:      <form method="post" action="demo.php">     Myname: <input type="text" name="myname" />      <input type="submit" name="submit" value="submit data" />    </form>   Somebody help please?


Injective restriction of $f(x) = \frac{ax-b}{cx-d}$

For $a,b,c,d \in \mathbb{R}$ and $ad-bc \neq 0$ I have the function $f : \mathbb{R}\setminus{\{d/c\}} \to \mathbb{R},  f(x) = \frac{ax-b}{cx-d}$. How can I find the largest possible restriction of $f$ such that $f$ is injective on it and the image of this restriction? Thank you for your help.   Edit: If I understand correctly, the linked question is concerned with finding a condition for injectivity on the parameters a,b,c,d (the condition they find is $bc-ad \neq 0$). With mine the values are already given.   Also I know that (as a continuous function) it's injective iff it is strictly monotone, which is the case when $f'(x) = \frac{bc-ad}{(cx-d)^2}$ is positive or negative. But I don't understand how this helps me, since the denominator is always positive and the numerator a fixed value for given bc and ad? If this is even the right approach for finding a restriction.


Table markup shows incorrectly in preview

When previewing a table that does not have the necessary linefeed before it, the preview shows up as if the table will render properly, but the eventual table does not. |some|table| |-|-| |here is my|table that will not render| |but it renders|in the preview below| To verify this, click "edit" and look at the preview below - it will look like a nice table! Here's an image of the preview for me:  This occurs on other stacks (I noticed it on Board Games, if it matters).  On Chrome, Version 88.0.4324.104 (Official Build) (64-bit), Windows.


Can someone help me with this unicode error?

File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/encodings/ascii.py", line 26, in decode     return codecs.ascii_decode(input, self.errors)[0] UnicodeDecodeError: 'ascii' codec can't decode byte 0xc2 in position 796: ordinal not in range(128)   My goal is get the text  from a text file and save it as a variable in my program. I do not know how it is encoded. If someone could tell me how to find out how it is encoded, that may also be helpful


Python: Creating an object in a loop produces objects with the same reference

I have a piece of code which I just cannot debug. Basically env is always the same object in every iteration (has the same reference). I know it has something to do with references being copied over, but I do not know where this happens. Can you please point out the issue if you can find it? I made a small runnable example which reproduces my issue: import copy   class Params:     def __init__(self, port):         self.__port = port      def set_port(self, port):         self.__port = port      def get_port(self):         return self.__port   class Env:     def __init__(self, params):         self.params = params   def make(env_class, params, ports):     env_fs = []     for port in ports:         params_ = copy.deepcopy(params)         params_.set_port(port)         env = env_class(params_)         env_fs.append(lambda: env)     return env_fs   if __name__ == "__main__":     fs = make(Env, Params(0), ports=[0, 1, 2, 3])     for f in fs:         print(f().params.get_port(), id(f()))  This outputs: 3 139624063550224 3 139624063550224 3 139624063550224 3 139624063550224  Process finished with exit code 0  Every object has the same reference.


how many pairs of plaintext-ciphertext are needed before we break AES?

Imagine a set of words ($plaintext$) each are encrypted using AES-ECB mode and due to some leakage in the system an attacker could gain access to some pairs of $plaintext$ and $ciphertext$. But once the attacker got bunch of such pairs he cannot further ask the oracle for any other pairs. So in reality how many such pairs of $plaintext$ and $ciphertext$ are needed to crack the $key$.   Here each input $|plaintext| < 128$ bits.


Proof with order and primitive root modulo

Fix a positive integer $d$ and a positive divisor $k$ of $\varphi(d)$, and suppose there exists a primitive root modulo $d$. Use the result of part (b) to prove that there are precisely $\varphi(k)$ elements of $(\mathbb{Z}/d\mathbb{Z})^\times$ whose order is $k$.  By taking $k=\varphi(d)$, deduce that there are $\varphi(\varphi(d))$ primitive roots modulo $d$. In part(b), I proved that there exists $\ell\in\mathbb{Z}$ for which $\overline{c}=\overline{b}^\ell$, and $\overline{c}\in\left\{\overline{1},\overline{b},\ldots,\overline{b}^{k-1}\right\}$. I'm struggling to find out how to use them to prove this statement...


In my infinite wisdom, I deleted the file 'mpicc.openmpi' file in my /usr/bin/ folder by mistake.   I tried installing OpenMPI as well as GCC. But don't know how to get back to normalcy.  Can anyone please help me out.  Thanks.


MacBook Pro Retina 2013 memory frequency limit

I would like to replace the 2x8 GB 1600 MHz DDR3 of soldered memory in my 15" 2013 MacBook Pro with some faster RAM. Is this MacBook Pro compatible?    This is not a duplicate question (Allan, patrix marked) because it about different device. Question about RAM frequency for specific device, not in general...


I need to cite the journal "Sankhyā: The Indian Journal of Statistics" in a paper.  I would like to draw the ā character properly (i.e., I'd prefer, if possible, to avoid using some hack, such as \bar or \overline).  Question: How do I properly write ā in LaTeX?  I didn't have luck with  (after several attempts in both in capital and lowercase) nor The Comprehensive LATEX Symbol List (searching the file for "ā" and "india" revealed no hits).


Prove quotient of two $N(0,1)$ is $\text{Cauchy}(0,1)$

Problem: Show that if $X$ and $Y$ are independent $N(0,1)$-distributed random variables, then $X/Y ∈ C(0,1)$.  Question: I don't know how to proceed below. I want to prove that the PDF of $X/Y$ is Cauchy. PS. I looked on wiki and they defined $C$ as $X/Y$  Attempt:   The expression looked hairy and  could not integrate it.   Note to self: problem 8.


How to pass parameters for output in C++

Some of methods that I see in C++ code are of this structure:  void Class::method1(int &a);   and are called like this:  int a; class->method1(a);   But sometimes I see structures like:  void Class2::method2(int* a);   And these methods are called like this:  int a; class2->method2(&a);   I understand that in the first case the method accepts an address of a variable, and in the second - pointer to a variable, right?  Could someone explain to me what is the difference between these two approaches, and when to use which?  Also, in the first example, it seems that a method can be taking "int& a" or "int a", and in both cases we would call it the same way: int a; class->method1(a); ? This seems confusing.  Thanks.


Reordering of layer properties fields in QGIS possible?

I'm wondering why such simple things are not possible.  I have 5 fields on my layer and the last one shall be on the top now. But there is no way to do this, is this correct?


The center of $A_n$ is trivial for $n \geq 4$

I need to prove that the center of $A_n$ is trivial for $n \geq 4$.  $Z(A_3) = A_3$, since $A_3 = \mathbb{Z}/3\mathbb{Z}$ is commutative.  One idea is two use "counting" technique. First of, all we count cojugacy classes of even permutations in $S_n$. It's the classes correspodning to the types $[\lambda_1, ..., \lambda_r]$ where $n \equiv r \mod 2$  Now, the conjugacy class in $S_n$ correspoding to the type $[\lambda_1, ..., \lambda_r]$ splits into two equal-sized classes in $A_n$ if $\lambda_1, ..., \lambda_r$ are distinct odd numbers. If they aren't then it is preserved in $A_n$.  Then we can use "the counting formula"(  ) of elements in each "even" class of $S_n$ and divide one by $2$ if needed.  Still, I'm not sure if it can be done. Seems to be a lot of work there. Maybe there are other, he easier ways? Or, maybe, it is the way, in this case, I wouild appreciate any advices.


Possible Duplicate:          In the rosary, a Catholic sacramental composed of prayer beads, there is a short prayer concluding each decade called "Glory Be" ("Glory be to the Father, Son and Holy Spirit...").  Would the plural be Glory Bes or Glory Be's?  Likewise, do you say 10 Hail Marys?


How to retrieve an underlying mathematical model from the decision tree or random forest?

I wonder if it is possible to retrieve something similar to regression equation from the trained decision tree or random forest for the regression problem? In particular, I want to know how much each attribute impacts on the response factor (not pair-wise, but in total). It is possible to measure feature importance, but can I then use this feature importance values as the equation, e.g. y = 0.2*x1 + 0.5*x2, where 0.2 and 0.5 are normalised feature importance values.   The duplicated answer is provided for random forest, but says nothing about simpler models like decision trees.


How do I share internet with Windows from my Linux box?

I have a Linux (Ubuntu 12.04) PC connected to the internet with a Greenpacket WiMax USB modem. I want to share the Internet connection with another computer running Windows 7 Home Premium, connected to the Linux PC over a LAN. Is this possible? How? Is the reverse possible instead (connecting the internet to the Windows computer and sharing it with Linux)?


Generalizing values which Euler's-totient function does not take

I was reading about Euler's totient function on wikipedia, and it eventually led me to this book on google:  .  Anyway, the books lists many assertions without proof, only references which I can't find. One I could not solve for myself said that not all even numbers are values of $\phi(n)$. The sequence of even non-values of $\phi(n)$ starts:  $14, 26, 34, 38, 50, 62,\dots$  After thinking about it for a while, I've made little headway. Looking at 14 specifically, I suppose if such a solution $a$ to $\phi(x)=14$ were to exist, $(a,m_i)=1$ for $1\leq i\leq 14$, for some $m_i\lt a$ and so there must also exist inverses $\overline{a_i}$ such that $\overline{a_i}a\equiv 1 \pmod {m_i}$ for each $i$. I'm looking for some contradiction, possibly of the Chinese Remainder Theorem, to show such $a$ cannot exist.   Is there some way to generalize which values are not taken by $\phi$, or at least explain why this is the case? I was hoping to see why $14$ is the least such integer such that this is true, but values $1$ to $13$ must be indeed taken. I suppose this would also explain why 26 is the next such value that is not taken, while $15$ to $25$ are.


What makes something iterable in Python? ie. can loop over it with for  Is it possible for me to create an iterable class in Python?  If so, how?


I read somewhere that the Alt Gr key found on some layouts is a substitute for Ctrl + Alt.  However, what can this combination be used for? Are there any documented shortcuts using Ctrl + Alt?


Are the Groups having all subgroups of same order conjugate classified?

As we know, Alternating Groups $A_n$ of degree $n\leq 5$, Dihedral Groups $D_{2n}$ of order $2n$ (for odd natural number $n$) and Cyclic Groups $C_n$ of order $n$ (for positive integer $n$) have subgroups of same order conjugate. Are such (finite) groups classified? Is there some more groups of this type?


Spurious " is expected to return a value" warning?

I'm working under Sun Studio 12.3 on SunOS 5.11 (Solaris 11.3). Its providing a spurious warning:     "<file.h>", line 1: Warning: "<function>" is expected to return a value.   The function is part of a base class interface and looks like so. I only mention the base class interface to avoid the "why would you do that" discussions. A non-member function like below is enough to trigger it.  int foo() {     throw runtime_error("Not implemented"); }   I found mention of similar problems. For example, the  change log states:        Disable " is expected to return a value" warning from Sun's C++   compiler, as it fires for functions ending in a "throw" statement.  Genuine   instances will be caught by compilers with superior warning machinery.      According to , I can use -erroff=voidretw. I'm concerned about -erroff=voidretw because it might suppress valid findings. Also, if I go with the #pragma, then I need to push and pop it to avoid cross pollinating into user code. I don't know how to push and pop warning states under Sun Studio.  My question is, how do I disable the warning for the one function in the header under Sun Studio?    This looks like a duplicate even though the message is different:  I think I am going to vote to close this as a duplicate.


How to know what is the model of my wireless card?

I am looking for command line which tells me what is the model of my wireless card? For example if that is Atheors. The result should be atheros.


Make camera follow and rotate with player without childing it

I want to have a camera, that follow the player, without childing it to the player object. So far I have this one line, that follows the player, but does not rotate with it (meaning the camera should look where the player's front is looking, how can I do it?  transform.position = player.transform.position + offset;


Upgrading packages through Terminal and knowing when a restart is then needed

When I run the application Software Updater and I install some updates which need a restart of my computer, it tells me that I need to restart.  But when running this command in Terminal:  sudo apt-get upgrade   It is not clear whether or not the packages which you have upgraded require a restart of the computer once they have finished upgrading. So I was wondering if and how you would check if any of the packages which you have upgraded need a restart of your computer?  I am running Ubuntu 14.10.


Overlaying one list on another list in C#

I know the code to efficiently overlay one list on another in python, using dictionaries. Here is what i mean:  input:    dictA = {'c':2, 'e':1};   print(dictA);   output:   {'c': 2, 'e': 1}   input:   dictB = {'a':0,'b':0,'c':0,'d':0,'e':0,'f':0};  print(dictB);   output:   {'a': 0, 'b': 0, 'c': 0, 'd': 0, 'e': 0, 'f': 0}   input:   dictB.update(dict(dictA));  print(dictB);   output:  {'a': 0, 'b': 0, 'c': 2, 'd': 0, 'e': 1, 'f': 0}   dictA is overlayed on dictB with the 'c' and 'e' now having the values they were assigned in dictA.  Question: What is the equivalent syntax in C# to overlay one list another as above?


Split cell data into separate cells at the "|"

I'm trying to figure out "how to" split one Google Sheets cell into multiple cells. I'm using the "|" character to identify where the string in one cell should will be split. Ideas?  I have the following in cell B1.  space|space | will always separate values in the single cell.   Chromebook 101 | GHS | 8:00 am | ID#100103  I need to split the data into FOUR parts and into FOUR different cells.   H1 = Chromebook 101 I1 = GHS J1 = 8:00 am K1 = ID#100103   The data is being added to Google Sheets via form input and I need this to update automatically. I assume an arrayformula will be needed.   If possible, I'd also like to drop the | from cells H1, I1, J1, and K1.


So my computer had a no signal black screen for almost 8-9 maybe 13 years finally got the black screen off and turns out my aunt who I let use my pc put a  password on my admin account. So I've looked up all the ways to  bring up the CMD on lock screen and no matter how I follow the steps perfectly. In system 32 I can not find the sethc  and all my files has DII behind them. I see no sethc.exe or anything close to it. I'm so lost and I don't wanna clean my PC because I'll have to redownload my Vista and anything else. That might be vital to my gaming. So any help will be a big help


Full screen an application on half of the window?

Is is possible to full-screen an application (like chrome browser, or Word for example) and only use 50% of the window space (either the left or right side).  The reason I ask such a question is that I love how clean my work-space gets  when you full screen applications. It can really help focus. But I'd still like to use side by side programs.   You lose the window borers You lose the status bars You lose the start menu (usually) You lose the menu bars, and window controls..   Full screening an application is very nice. But I only need it to be half the width of my monitor.   I've attached 2 images. They show what side by side non full screen does, and what I would like it to do (if possible).            Thanks!


How can I dynamically assign a value to a lightning record form?

For example, my component has the following section that displays a record form:  <template if:true={showRecordForm}>     <lightning-record-form         object-api-name={sObjectApiName}         onsuccess={handleFormSuccess}         record-type-id={recordTypeId}         layout-type="Full"         columns="2"         oncancel={handleFormCancel}         onload={handleFormLoad}>     </lightning-record-form> </template>   It will load the form for the object I specify in sObjectApiName, and with the specified record type as well. The problem is that I want to assign some values to specific fields.  Let us say that it is a Case form, and I want to assign an Account ID to the AccountId field, before the case is submitted to the platform.  I tried to query the lightning-input-fields, but with no success:  const inputFields = this.template.querySelectorAll(     'lightning-input-field' ); if (inputFields) {     inputFields.forEach(field => {         console.log(field)     }); }   This is a snippet from the .  I'm starting to think that this might not be viable, or too much trouble. Is there a way to do this?


Let's say that we have a matrix $A \in M_n{\mathbb{C}}$ such that $A^2=A-I_n$. Now,I want to see what I can say about its eigenvalues. I think that they are roots of the polynomial equation $x^2-x+1=0$(of course,they may come in any multiplicity). Is it true that all of $A$'s eigenvalues need to be roots of this equation(and have different multiplicities) or do only some of them need to be and the others can be any complex numbers? I believe that they all are roots of this equation and have different multiplicities,but I am not so sure.


Where should I post discoveries, share knowledge about a specific topic like programming?

I'm looking for a community that people can share knowledge about something, i.e. a new and faster algorithm. If this kind of community doesn't exist yet, would be a good idea a Stack Exchange about it.


Why is the proof that $\sqrt2$ is irrational must $p$ and $q$ be coprime?

I understand most of the proof except how it starts with that $p$ and $q$ in $\frac pq$ where $p$ and $q$ are integers and $q$ can’t equal $0$, that $p$ and $q$ must be coprime? Why must they be coprime? I don’t think it’s part of the definition of a rational number.


I messed the file bash.bashrc ubuntu 14.04

Trying to install java jre, I messed up the file bash.bashrc on Ubuntu 14.04, by adding these two lines at the end :  export PATH= $PATH:usr/java/bin/ ;  export JAVA_HOME= $JAVA_HOME:usr/java/bin/java/   Now I cannot do any command on terminal. When I open terminal it give me these errors:  bash: export: `/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:usr/java/bin/': not a valid identifier bash: export: `:usr/java/bin/java/': not a valid identifier bash: lesspipe: No such file or directory bash: dircolors: No such file or directory bash: ls: No such file or directory   Could anyone help?


Question: Sketch the complex region given by the inequality:  $$|z-1|\lt|z+1|$$  My attempt:  I tried to square both sides and use the fact that $z=x+iy$ however upon expanding I got a form that I couldn't recognise as any shape


I have a canon DSLR and even in Manual mode or with proper settings, I have to bump aperture, shutter speeed AND ISO to get photos to be even CLOSE to the right exposure. Currently have my ISO set to 1600 just to get a decent photo in natural light with Aperture at 4.5 and SS at 1/60. I shouldn't have to shoot like this and can't even THINK about shooting the low-light portraits that I love. Someone please help. There is no one in town that will repair on site and I don't want to send it out for something that could be simple, just never thought of!


I have ImageMagick installed but I can't uninstall

You can see with this pictures the ImageMagick software is installed.  And:  But if i try unistall: $ sudo dpkg --purge --force-all imagemagick dpkg: warning: ignoring request to remove imagemagick which isn't installed  $ snap remove imagemagick snap "imagemagick" is not installed  I tried other forms too and none are working.


Limit of $\exp(-2n) \sum_{k=1}^{n} \frac{(2n)^{k}}{k !}$ as $n \to \infty$

What is the limit of $$\exp(-2n) \sum_{k=1}^{n} \frac{(2n)^k}{k !}$$ as $n \to \infty ?$  I am getting the indeterminate form $0 \times \infty$ by applying limit directly.  I don't find any other way to solve this limit.


StringBuffer method parameter - doesn't change value

I know that String is immutable and it's value can't be changed, but why does the value of the below StringBuffer doesn't change when sent like a method parameter. From my understanding it should have changed with the new value "bb". Thank you for your help.   class Ideone {      public static void main (String[] args) {          String s = "aa";         StringBuffer sb = new StringBuffer("aa");         modify(s, "bb");         modify2(sb, "bb");         System.out.println(s);         System.out.println(sb);     }      public static void modify(String s, String ss) {         s = ss;     }      public static void modify2(StringBuffer sb, String ss) {         sb = new StringBuffer(ss);     } }


Why wouldn't a balloon suspended in an accelerating truck not move?

Consider this question: A helium balloon is held by a light string in the middle of the back of a very powerful truck. The back of the truck is sufficiently large that the balloon cannot hit the sides if it sways forwards or backwards on the string. The back of the truck is completely enclosed with no windows or ventilation from the outside. The truck now accelerates rapidly forwards. What is the motion of the balloon relative to the truck when the truck is accelerating? Does the balloon sway forwards, backwards or remain at the same position?  Now, the balloon should move forward as the air would be pushed backwards creating the higher pressure at the back. But the answer suggests that it won't move. How is that possible?


Why are tidal forces pointing away from the Moon?

I am currently reading The Science of Insterstellar, which explains most things very well, but some things leave me confuzzled, which I hope to get answers to here. I am no physicist, but highly interested and eager to learn.   I get tidal forces in principle, but one thing never clicked for me, and that is why tidal forces are the reason that the opposite side to the other object (moon, black hole, whatever) point away from said object.  Take this picture from wiki;      I understand all vectors up to the middle of the circle, where they point inwards and ever so slightly to the right.  Everything left from that is a mystery to me. How can the sum of all the forces pointing towards the object on the right result to vectors pointing away from it?  Even when I remembered that the object itself also has gravity in itself, all those vectors should also point inwards to the object.  How can the vectors (which I understand to be the sum of all gravitational forces ... ?) point away from the mass?


OpenVPN not redirecting all traffic to VPN tunnel when local network is 192.168.x on both sides

I've setup a OpenVPN server using tun and udp and enabled the options for redirecting all internet traffic and pushing lan to clients.  In the HOST NETWORK The OpenVPN Server is configured to dish out 10.8.0.x network addresses for OpenVPN clients where as the LAN clients are in the 192.168.x network.  It looks something like this.  ----------------------------------------- |            HOST NETWORK               | |     LAN Clients    +  OpenVPN Server  | |     192.168.1.x          10.8.0.x     | -----------------------------------------                      |             -------------------             |     INTERNET     |             -------------------                      |  ----------------------------------------  |           REMOTE NETWORK             |  |          OpenVPN Clients             |  |      Local Network 192.168.1.x       |  ----------------------------------------   The problem is when the REMOTE NETWORK OpenVPN client are connecting from a remote network but they themselves have a local address range of 192.168.1.x  In this scenario not all packets are sent over the tunnel. e.g. If the REMOTE NETWORK has a machine at 192.168.1.1 and after establishing the OpenVPN tunnel the remote OpenVPN client tries to access 192.168.1.1 it goes to the REMOTE NETWORK's machine rather than the HOST NETWORK's machine.  How do I tell/configure the remote OpenVPN client to send ALL traffic over the tunnel ignoring whatever the local network routes/addresses are?  I've searched all over and tried the remote-gateway def1/autolocal options but nothing seems to work, it's always sending the 192.168.1.1 packets to the REMOTE NETWORK machine instead of the HOST NETWORK machine.  This is my client config:  client dev tun proto udp remote hostnetwork.com 1194 float ncp-ciphers AES-128-GCM:AES-256-GCM:AES-128-CBC:AES-256-CBC cipher AES-128-CBC comp-lzo adaptive keepalive 15 60 auth-user-pass remote-cert-tls server <ca> -----BEGIN CERTIFICATE----- -----END CERTIFICATE----- </ca> resolv-retry infinite nobind redirect-gateway autolocal


Is heights of humans actually a discrete random variable?

Suppose the human population consisted of $N = 3$ people, each with a specific height. Let $X^N$ be the random variable representing the heights of this population of $N$ people. Since $X^N$ can only take $N = 3$ distinct values it is a discrete random variable with a probability mass function. For example, we could have $N = 3$ people with heights $150$ cm, $160$ cm, and $170$ cm, and thus the probability of any particular height occuring is $1/3$. Now, consider the case of $X^N$ when $N = 6$ billion, i.e. the heights of the real-world human population. We now have $6$ billion distinct values for $X^N$. Although there is now a very large range of values $X^N$ can take, it is still a discrete random variable as those $6$ billion discrete values are the only values of $X^N$ that can occur. Therefore, heights of humans is actually a discrete random variable and not a continuous random variable? Everywhere I look it says that human heights is a continuous random variable with a pdf, but it seems from the above that it is actually a discrete random variable with a pmf?


Can I overwrite a setting within sshd_config with a duplicate setting

I am implementing a basic deploy script and for sshd_config the only change that I need to make is PermitRootLogin yes to PermitRootLogin without-password. I have read through the docs and they make no mention of this but that is not to say it is impossible.  Can I specify a second PermitRootLogin? I.e. echo 'PermitRootLogin without-password' >> /etc/ssh/sshd_config  If so, is this safe?  Updates based on comments:  1) I am aware that I could parse the file and change the variable. My question still remains though.


Changing “/usr” directory permissions under Ubuntu recovery mode

I'm new to Ubuntu , while working with permissions I messed up with ~/usr directory and now I can't run sudo and pkexec both commands. Is there any other way to make ~/usr directory permission to default. I'm the root user and I tried several commands but none of them worked.   I entered into recovery mode and into root but it is saying read-only file system, can anyone give me step-by-step process to make it right. Thank you   Ubuntu was installed on server


"The lyrics to the song" vs. "the lyrics of the song"

Do you remember the lyrics to the song?   Do you remember the lyrics of the song?      I'm more familiar with the second sentence using the "of". But what I don't know is, how would you interpret both of these sentences in the grammatical sense? Do both of these sentences express a relation between lyrics and songs?


What is the difference between /dev/sda and /dev/hda?

Sometimes internal harddrives are available as /dev/sda (with subsequent media located in /dev/sdb etc), and other times available as /dev/hda. What is the difference between the two?  Does it vary between Linux distributions, or is it based on the computer hardware, or perhaps the harddrive type?


Proving $\sum_{i=1}^n 2^i = 2^{n+1} - 2$ using strong induction

I just started learning proof by induction in class, but got a problem requiring proof by strong induction.  Here is the problem.     Prove by strong induction: $$\sum_{i=1}^n 2^i = 2^{n+1} - 2$$   I've done the base, showing that the statement holds for $n=1$, $n=2$, and $n=3$. (I won't show the simple math here). For $n=k$, the statement would be $2^{k+1}-2$. But that's where I get stuck, as I'm still trying to grasp the concept of strong induction.  For $n=k+1$, do I do the following and simplify?  $$\sum_{i=1}^{k+1} 2^i = \sum_{i=1}^k 2^i + 2^{(k+1)+1} - 2$$ $$=[2^{k+1}-2]+[2^{k+2}-2]$$ $$=\text{etc}\ldots?$$


How to represent table of contents in a table via LyX

I am in need of urgent help regarding formatting the table of contents in Latex. In the thesis preparation guidelines provided by our university, the table of contents, list of figures and list of tables details should be enclosed within a table as shown below:    In this connection, my question is How to generate the TOC, LOF, and LOT automatically in the above mentioned format using LyX.


An anchor at the bottom of the /reputation page

Would be nice with something like a #bottom anchor at the bottom of the  page.  (Scrolling to the bottom isn't much of a problem when I'm on a laptop, but it's really terrible when I'm on my iPad or on my cell phone.)


I want nanoTime() of last 24 hours. long currentDate=System.nanoTime(); how to find nanoTime by subtracting 24 hours? Is it possible to get nanoTime from Date date = new Date()?


How can I replace lone instances of \n with \r\n (LF alone with CRLF) using a regular expression in C#?  Sorry if it's a stupid question, I'm new to Regex.  I know to do it using plan String.Replace, like:  myStr.Replace("\n", "\r\n"); myStr.Replace("\r\r\n", "\r\n");   However, this is inelegant, and would destroy any "\r+\r\n" already in the text (although they are not likely to exist).


Upon resuming my machine, the background image turns white, and all of the windows have thick white borders around them.  This started happening after I "played" with my Nvidia drivers by upgading to the latest version. Tried to change/downgrade driver versions, reinstalling unity, but without luck so far...  Using a Dell 7559 with the Nvidia proprietary driver (nouveau just does not work well for me...), ubuntu 16.10 and latest kernel 4.10.1  Here is an depicting this situation:    Thanks!


Physical laws prior the big bang (quantum fluctuations)

A theory among scientists says that quantum fluctuations caused the big bang and created the universe. This seems plausible to me.   What I can't grasp yet is how a quantum fluctuation can even start without an existing universe. Aren't all physical laws created with the universe? I understand that there is no notion of "before" with respect to time, however the big bang is theorised to have occurred, but for that to occur there must have first existed something right?  I wonder also, if there was a more nothingness instead of vacuum before the universe existed and how a quantum fluctuation could have started really from ex nihilo instead of a vacuum.


We are working with current version of Apache 2.4. 6 available in a Centos 7 repos. Installed with yum.  and we are dealing with the PCI compliance and the report says:  IP Address: x Host: x Path:   THREAT REFERENCE  Summary:  vulnerable Apache version: 2.4.6  Risk: High (3) Port: 443/tcp Protocol: tcp Threat ID: web_server_apache_version  Details: Apache HTTP Server mod_proxy_fcgi Response Handling Vulnerability 11/21/14 CVE 2014-3583 Apache HTTP Server before 2.4.11 is prone to a vulnerability, which can be exploited to cause a DoS (Denial of Service). The vulnerability exists due to an overflow condition in mod_proxy_fcgi. when handling responses from FastCGI servers. The vulnerability can be exploited by sending a crafted response from a malicious FastCGI server, which could lead to a  crash when reading past the end of a heap memory.  Apache HTTP Server NULL Pointer Dereference Vulnerability 10/08/14 CVE 2014-3581 Apache HTTP Server 2.4.10 and earlier is prone to a vulnerability, which can be exploited to cause a DoS (Denial of Service). The vulnerability exists because the application contains flaw in the cache_merge_headers_out() function which is  triggered when handling an empty 'Content-Type' header value.  Multiple Vulnerabilities Fixed in Apache HTTP Server 2.4.10 07/24/14 CVE 2014-0117 CVE 2014-0118 CVE 2014-0226 CVE 2014-0231 CVE 2014-3523 Apache HTTP Server before 2.4.10 is prone to multiple vulnerabilities, which can be exploited to cause a DoS (Denial of Service). The vulnerabilities exist because the application contains flaw in  mod_proxy, mod_deflate, mod_status, and mod_cgid modules and in the winnt_accept function of WinNT MPM.  Note: the WinNT MPM denial of service vulnerability can only be exploited when the default AcceptFilter is used. Apache HTTP Server Two Denial of Service Vulnerabilities 03/19/14 CVE 2013-6438 CVE 2014-0098 Apache HTTP Server before 2.4.9 is prone to two vulnerabilities, which can be exploited to cause a DoS (Denial of Service). The first vulnerability exists due to an error in the mod_log_config module when logging  with truncated cookies. The second vulnerability is due to a boundary error in the mod_dav  module when removing leading spaces. HTTP-Basic Authentication Bypass Vulnerability 08/14/09 Apache 2.2.2 and prior are prone to an authentication-bypass vulnerability  because it fails to properly enforce access restrictions on certain requests to a site that requires authentication. An attacker can exploit this issue to gain access to protected resources,  which may allow the attacker to obtain sensitive information or launch further attacks. Apache HTTP Server OS Fingerprinting Unspecified Security Vulnerability 11/03/08 Apache 2.2.9 and prior is prone an unspecified security vulnerability.  Information From Target: Service: https Received: Server: Apache/2.4.6 (CentOS) OpenSSL/1.0.1e-fips PHP/5.6.13   We update the server once a week "yum update"  but when i do:  rpm -q --changelog httpd | grep CVE i can see this:   core: fix chunk header parsing defect (CVE-2015-3183) and ap_force_authn hook (CVE-2015-3185) core: fix bypassing of mod_headers rules via chunked requests (CVE-2013-5704) mod_cache: fix NULL pointer dereference on empty Content-Type (CVE-2014-3581) mod_cgid: add security fix for CVE-2014-0231 (#1120608) mod_proxy: add security fix for CVE-2014-0117 (#1120608) mod_deflate: add security fix for CVE-2014-0118 (#1120608) mod_status: add security fix for CVE-2014-0226 (#1120608) mod_cache: add secutiry fix for CVE-2013-4352 (#1120608) mod_dav: add security fix for CVE-2013-6438 (#1077907) mod_log_config: add security fix for CVE-2014-0098 (#1077907)   How can i apply the patches that the security scan is asking for? i cannot find rpms to do it.  thanks in advance.  Regards.


Riemann integrability of continuous function defined on closed interval

Theorem says that if $f:[a,b]\longrightarrow \mathbb{R}$ is a continuous function, then it's integrable in Riemann's sense. Here's my proof:  Proof  Let $\mathfrak{P}=\{x_0,x_1,...x_n\}$ be a subdivision of $[a,b]$. Let denote $m_k=\inf_{x\in[x_{k-1},x_k]}f(x)$, $M_k=\sup_{x\in[x_{k-1},x_k]}f(x)$ and a diameter as $\max_{k=0,1...,n}(x_{k+1}-x_k)$. Then, the lower Darboux sum is $s(f,\mathfrak{P})=\sum_{k=1}^n m_k(x_k-x_{k-1})$ and upper sum is $S(f,\mathfrak{P})=\sum_{k=1}^n M_k(x_k-x_{k-1})$.  We know that $f\in\mathfrak{R}([a,b])\iff \forall_{\epsilon >0}\exists_{\mathfrak{P}}:S(f,\mathfrak{P})-s(f,\mathfrak{P})<\epsilon$  Every funtion continuous on closed interval is also uniformly continuous, so $$\forall_{\epsilon >0}\exists_{\delta >0}\forall_{x_1,x_2\in [a,b]}:|x_1-x_2|<\delta \Rightarrow |f(x_1)-f(x_2)|<\frac{\epsilon}{b-a}$$  This means that for every subdivision $\mathfrak{P}$ of a diameter smaller than $\delta$ we get $$S(f,\mathfrak{P})-s(f,\mathfrak{P})=\sum_{k=1}^n(M_k-m_k)(x_k-x_{k-1})\leq \frac{\epsilon}{b-a}(b-a)=\epsilon$$ which ends the proof.  Is it understandable and, what's more important, correct?


Can a phrase be the object of a clause and how would its subject change?

Take the  sentence:     I speak all over to whoever will listen.   ...at first blush, I thought, "Ah — whoever should be whomever."  However, I then noted that in the phrase "whoever will listen", whoever is correct.  I think the central issue is that if the sentence had ended without the "...will listen" then it would be correctly stated, "I speak all over to whomever."  As it is, it seems like the last part of the sentence ("whoever will listen") ends up being the object of the 'to' rather than the single word: 'whoever'.  Is this sentence grammatically correct, and why?


Trisquel:What to type when I set a blank password?

I recently installed trisquel on my computer. When I decided to use the terminal and sudo I was prompted to use a password despite the fact that I set a blank one.  I want to know what I am supposed to type then.  I am open to going into grub and somehow replacing the password.  I have tried out pressing enter at the terminal to no avail.  I am the root user and cannot make changes without the password.


How do I disable system's alt+grave on 14.04?

The solution  does not work.  I'm trying to use alt+grave on ccsm, but Unity's shortcut is taking precedence. How can I disable Unity's version of alt+grave?  Thank you!


Proof of Geometric mean $\le$ Arithmetic mean

This is a problem from Spivak's Calculus.  If $a_1, \dots, a_n \ge 0$, then the "arithmetic mean"   $$ A_n= \frac{a_1+\cdots +a_n}{n}$$  and "geometric mean"   $$ G_n= \sqrt[n]{a_1 \dots a_n}$$  satisfy $G_n \le A_n$.  Suppose that $a_1 \lt A_n$. Then some $a_i \gt A_n$; for convenience, say $a_2 \gt A_n$. Let $\bar a_1=A_n$ and let $\bar a_2=a_1+a_2- \bar a_1$. Show that $\bar a_1 \bar a_2 \ge a_1a_2$.(This part is easily done). Why does repeating this process enough times eventually prove that $G_n \le A_n$? (This is another place where it is a good exercise to provide a formal proof by induction, as well as an informal reason.) When does equality hold in the formula $G_n \le A_n$?  I don't see how I can generalize this process to achieve the result. I would appreciate any hint, suggestions, or solutions.


My if statement will never equal true - Why?

I've been working on an app, and in a certain activity, a if statement seems to never equal true but I can't figure out why. I suppose it has something to do with the SharedPreferences. Could someone take a look at my code and see why this is happening so I could prevent it later on while typing more complex code?  This is the activity I'm having trouble with:  public class SignInActivity extends AppCompatActivity {      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.content_main3);          SharedPreferences example = getSharedPreferences("label", 0);         final String username = example.getString("username", "nothing found");          final Button LogInButton = (Button) findViewById(R.id.LoginButton);            LogInButton.setOnClickListener(                 new Button.OnClickListener(){                     public void onClick(View v){                         EditText userNameInput = (EditText) findViewById(R.id.UsernameLogIn);                         String userString = userNameInput.getText().toString();                           if (username == userString){                             Intent nextScreen = new Intent(getApplicationContext(), MainActivity.class);                             startActivity(nextScreen);                         }                     }                 }         );     } }


I'm new to Latex and am having trouble troubleshooting an equation that I can't get to display correctly. The equation I am trying to create in Latex is:   ...but I keep getting nested fractions starting with the 3rd to last term so it appears like:   The code I am using is:  \begin{equation} \centering \frac{\partial UB}{\partial t}+\frac{\partial UUB }{\partial x}+\frac{\partial WUB}{\partial z}=gB\sin\alpha+g\cos\alpha B\frac{\partial \eta}{\partial x}-\frac{g\cos\alpha B}{\rho} \[\int_\eta^z \frac{\partial \rho}{\partial x}dz\]+\frac{1}{\rho}\frac{\partial B\tau_x_x}{\partial x}+\frac{1}{\rho}\frac{\partial B\tau_x_z}{\partial z}+qBU_x \label{eqn:horizontalmomentum} \end{equation}   I'm also getting a whole bunch of errors:


I´m a new in Sharepoint and I have to do this, I need to send an email 7, 5, 3 day before a due date.  I´m using SPD 2013  Thank you for your help


A set which satisfies all conditions for a Group except associativity

I have a question which I can't seem to prove or dismiss.  Can a set of elements A satisfy al the conditions for a group except associativity (which leaves us with closure, identity and invertibility).  Tried to prove it but can't seem to make a table which fullfiles these actions.  Thank you.


Given a known power supply, what are safe ranges for the volts/amps/ohms of connected components?

I'm new to hardware and am coming from a software background. I have an SoC that will be powered by a supply generating 5V and 1A. I'm trying to figure out what are the safe ranges of volts/amps/ohms that I can use for various components that I'll be connecting to this SoC. For instance, say I want to add a transceiver to the SoC so that it can communicate with some other device:   Does the transceiver need to be rated above or below or exactly at 5V? Does the transceiver need to be rated above or below or exactly at 1A? Any resistance/ohm regulations/ranges that I need to consider?   I guess I'm trying to learn how to make a decision like the following:     My power supply is 5V and 1A. I see that Transceiver A is rated for 3V and 500mA. Perhaps its fine that its only rated for 500mA and that it will be receiving 1A, but perhaps it's not fine that its only rated for 3V but it will be receiving 5V. Hence, I would not want to use this particular transceiver.   Even if the logic in the blurb above is wrong (from an electrical standpoint), it underscores what I'm trying to understand here: given a known power supply, how do component ratings (for volts, amps, ohms) affect my decision of whether to use them or not?


Redirect to a login page when accessing androids tethered hotspot

I have an android device which i want to use to provide internet to a group of people. I want to leave the wifi open but a user must acquire a username and a password to properly login to our internet.  Once a user is connected to our wifi,i want the user to be redirected to our login page. Is there an android hotspot app that can enable me to redirect a user to a custom page?.


When I open a new terminal, it doesn't execute auto-start my bash_profile. I need to do "source .bash_profile".   When I use Screen, it happens again.


How can i demonstrate the only matrix which commute with every matrix it's $aI_n$? Thanks so much. I have no ideea how can i demonstrate that, it's too obvious. :/


After windows failed to format my external raw drive, I gave a shot to Gparted in linux. Gparted says "ërror input/output error during read on /dev/sdb" Clicking ignore I can see my drive labeled "unallocated" trying creating a new partition table it says "libparted bug found, ërror input/output error during read on /dev/sdb "  I have looked on many answers and cant seem to help. I have also tried cfdisk, fdisk without success.


How I can find out which views use other views in their sql code that generates them?

I am mapping the view usage on an uknown database scheme. I was provided with a list with some views: view_a view_b view_c  And I want to search my database which views depend on another views for example if view_c is generated via the following sql query: CREATE VIEW view_c AS SELECT * from view_a JOIN view_b WHERE view_a.column=344  I want somehow to list that view_c uses view_a and view_b upon excell sheet. For now is done manually via looking the views dll sql on Dbeaver and figuring out from it. But it is very laborious job and may miss some view dependencies as well, so do you have any idea how If I can generate the excell sheet via a query from information_schema.* tables?


Is there any formula of monadic second-order logic that is only satisfied by an infinite set?

Is there any formula, of monadic second-order logic, that is only satisfied by an infinite set?


How to determine Windows versions previously installed

Is it possible to determine which, if any, Windows versions were previously installed on a machine?  Use case example: I'd like to find out if Windows 2012/2016 images we use were in-place upgrades or to be able to show that a machine has not been a fresh install since whatever version.  I've done some poking around within the registry, wmic, etc. but can't find any remnants that point to previously installed Windows versions.


Proof of standard limit $\lim_{x \to 0}(1 - \cos x)/x^{2}$

$$\lim_{x\to 0} \frac{1-\cos(x)}{x^2}=\frac{1}{2}$$  Proof: $$\lim_{x\to 0} \frac{1-\cos (x)}{x^2} \times \frac{1+\cos (x)}{1+\cos(x)}$$ $$\lim_{x\to 0} \frac{1-\cos^2(x)}{x^2(1+\cos (x))}$$ $$\lim_{x\to 0} \frac{\sin^2(x)}{x^2(1+\cos (x))}$$ $$=\frac{1}{2}$$ Hence we prove it. But I try to use $\varepsilon$  & $\delta$ method but I was not able to complete the proof. Some one help me to prove it using $\varepsilon$ and $\delta$ method. Thanks in advance.


Ubuntu/win 7 dual boot only boots to minimal grub prompt?

I was having trouble with my ubuntu dual boot so I ran the boot repair usb and was able to boot normally once. I tried to boot again and a screen with minimal grub bash 1.99 came up. I tried the boot repair again and the same screen came up. Here is info from the boot repair.


class Main(QtGui.QMainWindow):     self.process = QtCore.QProcess(self)     QtCore.QObject.connect(self.process,QtCore.SIGNAL("finished(int)"),self.processCompleted)      def processCompleted(self):         self.ui.statusText.setText("Finished")     self.process.startDetached(command,arguments)   I am not able to get the finished signal emitted here. Can anybody help me here.


Why don't the commands 'sudo bash' or 'sudo -s' ask for a password?

Even when I am logged in as a non-admin user, when I enter sudo bash or sudo -s, the system does not ask for any password. In the command history, I have not entered any password for sudo earlier (i.e., sudo did not cache any user credentials which might cause it to not ask for my password again in this session.)  Why is this strange behavior? And how do I make sure that every sudo and su command requires a corresponding password? And how to strictly ensure that any user cannot get root privileges without entering the root password?  Here is the content of my /etc/sudoers file:  # # This file MUST be edited with the 'visudo' command as root. # # Please consider adding local content in /etc/sudoers.d/ instead of # directly modifying this file. # # See the man page for details on how to write a sudoers file. # Defaults    env_reset Defaults    secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"  # Host alias specification  # User alias specification  # Cmnd alias specification  # User privilege specification root    ALL=(ALL:ALL) ALL  # Members of the admin group may gain root privileges %admin ALL=(ALL) ALL  # Allow members of group sudo to execute any command %sudo   ALL=(ALL:ALL) ALL  # See sudoers(5) for more information on "#include" directives:  #includedir /etc/sudoers.d ALL ALL=(ALL) NOPASSWD:ALL


How can i retrieve default post per page value? from settings->reading. And total number of posts?

I want to retrieve the default value of Post per page (the value that is set in settings->reading.  I've looked around and so far I've only found ways to query it. problem is i dont want to change what was set i just want to retrieve it for pagination purposes. i thought of using $something->post_count.(i might be wrong but as i understand it returns the amount of posts displayed currently) but this could be wrong in some cases.  Also how can i get the total number of posts ?


I have strings that need to be placed into lists; for instance I require that  C C .0033 .0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' C   becomes  ['C', 'C', '.0033', '.0016', 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4', 'C']   So everything in quotes becomes a single list element; otherwise, everything separated by whitespace becomes a single list element.  My first idea was a simple split, place the items that don't contain ' into a new array, and then place the ones that are in a quoted-section back together:  >>> s.split() ['C', 'C', '.0033', '.0016', "'International", 'Tables', 'Vol', 'C', 'Tables', '4.2.6.8', 'and', "6.1.1.4'", 'C'] >>> arr = [] >>> i = 0 >>> while i < len(s):         v = ''         if s[i].startswith("'"):             while not s[i].endswith("'"):                 v = v.append(s[i]+ " ")                 i += 1             v.append(s[i])             arr.append(v)         else:             arr.append(s[i])   But this strategy is pretty ugly, and in addition I have to assume that the string was split on a single space.  s.partition("'") seemed very promising:  >>> s.partition("'") ('C C .0033 .0016 ', "'", "International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' C")   but it's awkward because I have to partition again as I iterate through, and it's context-sensitive as to which one was in quotes.  Is there a simple Python3 way to split this string as described above?


Post migrated to meta can be double up voted

Recently we moved a post to meta that was on main. While on main it garnered several upvotes, including one from me. When it appeared the UV button didn't have the pressed look... so I pressed it and the count went up. Other users confirmed the behavior. This allows users to double upvote a post


A set with a finite integral of measure zero?

Prove, or give a counter example: Let $\mu$ be a finite positive borel measure on $\mathbb{R}$. Then $\int (x-y)^{-2} d \mu (y) = \infty $ almost everywhere on $\mu$ (for the selection of x's).  This is a question I had in an exam, and the answer is supposed to be presented in less than 30 words, so there must be something quite simple I'm missing.


In apa.cls [man] mode, how do you get the table to go with text?

My table consistently skips to the very last page! Is this simply a function of the doc mode? I have tried various float controlling methods like \FloatBarrier, etc., but nothing has been successful so far.  On the  it says:      When revising and proofreading a manuscript, it is most helpful to   have the tables and figures readily available (rather than turning   most of the way to the end of the manuscript to access them). If the   user invokes the floatsintext option (in the \documentclass line),   tables and figures will be integrated in the text approximately at the   point where they are mentioned.   I tried this but maybe I read it wrong.


Speeding up explorer.exe global shortcuts

I'm running Cygwin on windows with cmder as a terminal for zsh. The way I got it to be a bit similar to what my linux setup has is I placed a shotcut (.lnk) on my desktop with a keyboard shortcut (which I assume is handled by explorer.exe) for ctrl+alt+t. However, when I use the shortcut, the startup time is enormous (same for mintty), multiple seconds at least. At the same time, starting off by simply clicking the icon twice results in near instantaneous startup. Why is this the case, and is there any faster alternative to starting up a terminal?    Moved to AutoHotKey as a long-term solution.


why are squares of gradient used in adaptive learning rates techniques like rmsprop?

Please elaborate the answer and would further like to add, what if we don't use squared derivatives.


Ubuntu 16.04 some applications take too long to start up

When I start up Ubuntu 16.04 some applications take too long to run the first time I open them, including Chrome and any PDF viewer. Others, like nautilus, start up immediately.  The first time I try to use a PDF viewer like okular, it takes too long to open. After it opens a PDF file for the first time, other files open quickly. Even if I close all and open some after a long time, it happens quickly.  How can I speed up these programs opening on the first run?


I am looking for a proof that the standard unit square in $\mathbb{R}^2$ is not a variety. To be a variety I only require that it be the solution to a system of polynomial equations.


TikZ & WinEDT project: compile test file

when working on a WinEDT project with many files and a main file, how can I compile another file without closing the project altogether?  Imagine I want to create a TikZ figure, which involves many compilation iterations, and because i don't want the whole document compiled each time i moved the TikZ figure to a new .tex file.  Thanks!


What is the use of 'javascript:methodName(); in an anchor link?  I have seen the following in some code. What is use of the "javascript:"?   Click   It works if in both (with and without "javascript:") condition.


How do I download Google Chrome on Ubuntu 17.04?  I hit download on the Google website, and in my files it shows up as a package called google-chrome-stable_current_amd64.deb  When I click on it, it brings up google-chrome-stable from Ubuntu software, and nothing happens when I hit install. (I have tried restarting my computer).  Is there another way to download it?


How can I join a Lubuntu machine to a Windows 2008 domain?

I have a Lubuntu machine and I want to join it to a Windows domain. I've read that you need to download extra software to make this work, does anybody have any suggestion??


Visualforce page redirects to sandbox org

My visualforce page opens in the sandbox it was created in, even when I'm in a different sandbox.  I created a page and controller, which worked fine, in sandbox (dev1). I deployed it to a staging sandbox (staging1) and when I access it I'm redirected to dev1, whatever I do, and regardless of whether I'm logged in at the time.  This happens when I access the page by:   Using the custom URL button I created. Clicking preview on the page screen in setup. Adding the page directly in the URL.   What's going on?


For how long should alerts be displayed? By alert I mean messages such as "You are now logged out." in this page:    Normally, they disappear when the user clicks on some link and the page reloads, but this is a single-page-application, the page never reloads (unless the user decides to do so manually).  So, for how long should it be displayed? Any amount of time feels both very short and very long. Leaving it forever (until the user closes it) might not be a good idea either.


How can I use my laptop like an external hdd with use of any cable

I want to use my laptop like an external hard drive.  How can I completely access my laptop's storage on another computer with the help of any cable?  Can we mount a particular partition of the laptop on another PC?


What's the best lens for shooting baby and kids with a DX Nikon?

I have a Nikon D5100 and want to see whats the best lens for shooting pictures of a baby and kids running around inside and outside?  I would like to stay under $1,000.  Thanks for the help.


Why can questions only be migrated to the meta site of the main site?

Sometimes there are questions asked on a site, but never belong to this site, and are a very good fit for another site. In such cases I would like to vote to migrate this question to the site it fits. However, I can't see such option. For example,  Workplace.SE question fits Security.SE (or perhaps Stack Overflow?), but I can only vote to migrate this question to the corresponding meta site. Is this intentional? Do I not have the privileges to do this? I can't see such a privilege among the .  I am not sure whether it is a bug, something intentional or was not yet implemented, so I am tagging this as .


When I study Topology, I met with a problem. On my book, it says 'we cannot admit that there exists a set whose members are all the topological spaces. That will lead to a logical contradiction, that there will be a set who is a member of itself.' But why we cannot have a set who is a member of itself?


How do I switch opened windows within the same application using shortcuts?

As shown in the figure below, I opened three Safais windows. To switch among them, I double click the Safari ico in the dock and select the window.    Is there any shortcuts to move these opened windows?


Android Program Crashing NullPoint Exception

Hey so I have been trying to fix this problem for a couple of hours and checked a lot of the other questions extensively in an attempt to remedy this problem.   So in my Main Activity I have two activities that both either grabs an image from the gallery or is a photo depending on the button  public void DoTakePhoto(View v) {         Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);         if (intent.resolveActivity(getPackageManager()) != null) {             startActivityForResult(intent, TAKE_PICTURE);         }     }  public void DoShowSelectImage(View v) {     Intent i = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);     startActivityForResult(i, SELECT_PICTURE); }   So I know the problem likes on my onActivityResult where the data seems to be null I tried using the super so it gets back the lost activity or checking to see if data is  @Override     protected void onActivityResult(int requestCode, int resultCode, Intent data) {          super.onActivityResult(requestCode, resultCode, data);           if (requestCode == SELECT_PICTURE || requestCode == TAKE_PICTURE  && null != data) {             if (resultCode == RESULT_OK && null != data) {                 Uri selectedimage = data.getData();                 String[] filePathColumn = {MediaStore.Images.Media.DATA};                  Cursor cursor = getContentResolver().query(selectedimage, filePathColumn, null, null, null);                 cursor.moveToFirst();                  int columnIndex = cursor.getColumnIndex(filePathColumn[0]);                 mImageFullPathAndName = cursor.getString(columnIndex);                 cursor.close();                 jobID = "";                 File file = new File(mImageFullPathAndName);                 Bitmap mCurrentSelectedBitmap = decodeFile(file);                  if (mCurrentSelectedBitmap != null) {                      ivSelectedImg.setImageBitmap(mCurrentSelectedBitmap);                       int w = mCurrentSelectedBitmap.getWidth();                     int h = mCurrentSelectedBitmap.getHeight();                      int length = (w > h) ? w : h;                     if (length > OPTIMIZED_LENGTH) {                         float ratio = (float) w / h;                         int newW, newH = 0;                          if (ratio > 1.0) {                             newW = OPTIMIZED_LENGTH;                             newH = (int) (OPTIMIZED_LENGTH / ratio);                         } else {                             newH = OPTIMIZED_LENGTH;                             newW = (int) (OPTIMIZED_LENGTH * ratio);                         }                         mCurrentSelectedBitmap =     rescaleBitmap(mCurrentSelectedBitmap, newW, newH);                     }                      mImageFullPathAndName = SaveImage(mCurrentSelectedBitmap);                 }             }         }      }   So my Error   java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, data=Intent { act=inline-data (has extras) }} to activity {com.example.zola.capchem/com.example.zola.capchem.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.getScheme()' on a null object reference   I have tried most of the things on this site but the app still ends up crashing. No clue what to do here.


Why do we sometimes use "there is" for a plural form in our sentences? Example: "There is some cars". Is this true?


What does it mean by phases in Marvel Cinematic Universe?

See this picture:  I Saw this picture in wikipedia article:  I following marvel universe since childhood, but never came across this PHASE thing.  actually what does it mean?


What does the notation $\binom{n}{i}$ mean?

What do the parentheses next to the summation involving the binomial coefficients mean? Like this: $$\sum  _{i=0}^{n} \binom{n}{i}a^{(n-i)}b^i=\left(a+b\right)^n $$


$P[X=x]=0$ when $X$ is continuous variable

I know that for continuous variable $P[X=x]=0$.   But i can't visualize that if $P[X=x]=0$, there is infinite number of possible $x$'s. And also why do their probabilities get infinitely small ?


How do I switch between virtual terminals in a guest system?

I want to access virtual consoles in my Ubuntu guests running VirtualBox with Ubuntu guest. However, even if the focus is within the guest window, if I press Ctrl+F1 thru F6 I move in a virtual terminal of the host, not the guest.  How do I switch to a virtual terminal in the guest OS?


how to solve this below runtime error 430?

I created one application (*.exe) it works fine in all systems but in one system it throws an error.     "class does not support automation or does support expected interface "


Is there a way to hide Custom Settings and Metadata Types to Profiles? Thank you in advance! :)