So I'm creating a simple grep command that gets only the last logged in people who's username starts with 161 and has 3 digits next to it:  last | grep "^161[0-9]{3}"   However it doesn't print anything even though it has these usernames on the list. Whats even more weirder is if I do egrep instead of grep  last | egrep "^161[0-9]{3}"   The command works.  Can anyone explain what is the difference?


jQuery Array Element not Removing when Clicked

I'm trying to build a simple demo in jQuery of creating new elements and being able to delete them. I'm not sure why, but I cannot get this to work in jQuery. I can in JavaScript and have built a working demo here:   It seems that the code that doesn't work is this part:  /* NOT WORKING */     $.each(removes, function(el) {       el.on("click", function(){         let removedId = $(this).parent().attr('data-id');         $(this).parent().remove(); console.log('removed id ' + removedId);         updateElements();       });     });    Codepen URL:   I'm not massively experienced in jQuery and don't know why the above isn't working. It should just iterate through each array item (or .remove class) and add an event listener that, when clicked, removes its parent (row).  Can someone explain what specifically is going wrong here and demonstrate how to fix it? Any best coding practices would be much appreciated. Thanks for any help here.  Here's the complete code in jQuery:    // defaults var id = 1, objects = [], removes = $(".remove"); updateElements();  function createEntry() {   id++;    // create new element, append to #container & create new object   var container = $('#container'),       newEntry = $('
'),       title = 'title text here',       description = 'description text here',       remove = 'remove',       dataId = id,       obj = new Entry(title, description, remove);   newEntry.addClass("entry");   newEntry.html('' + title + '' + description + '' + remove + '');   container.append(newEntry);   newEntry.attr('data-id', id);    updateElements();    // constructor & push into array   function Entry(title, description, remove) {     this.title = title;     this.description = description;     this.remove = remove;     this.id = id;      objects.push(this);   }    // tests   console.log('JSON.stringify(objects[0]): ' + JSON.stringify(objects[0]));   console.log('obj.title: ' + obj.title);   console.log('JSON.stringify(obj): ' + JSON.stringify(obj));   console.log('obj.id: ' + obj.id); }  function updateElements() {   removes = $(".remove");   listenForRemoves();    function listenForRemoves() {          /* NOT WORKING */     $.each(removes, function(el) {       el.on("click", function(){         let removedId = $(this).parent().attr('data-id');         $(this).parent().remove(); console.log('removed id ' + removedId);         updateElements();       });     });       } } button { display: block } .entry {  width: 100%;  display: block;  padding: 10px;  border: 1px solid #f5f5f5; } span {   display: block;   width: 100%; } section { background: lightgreen }  <button id='btn' onclick='createEntry()'>Create</button>

   title text here   description text here   remove


Find two connected graphs, with the same score. One of them having hamiltonian cycle and the other not.

I want to find two connected graphs, with the same score. One of them having hamiltonian cycle and the other not.   Do such graphs even exist?


Why is "poweroff" a symlink to "reboot" in 12.04?

Today in class, the teacher asked us to say different ways to shutdown/reboot,etc. the system. I said "poweroff" and I though that it was probably actually a symbolic link to "shutdown" or "halt".  We are using Ubuntu 12.04 and when I checked it turned out to be a link to "reboot" which kind of surprised me. How does that make sense?  In my Raspberry Pi running Debian I get: /sbin/poweroff: symbolic link to 'halt'  EDIT: I don't see how my question is answered there.It mentions that when forcing shutdown poweroff invokes the reboot syscall, but doesn't answer why it is linked to reboot(1)


why does printing variable[array] output array elements?

During a Quiz,we were supposed to find the output of the following code: #include<stdio.h> int main() {      int a[3] = {10,12,14};      int i = 0;      while(i<3)      {          printf("%d\n ",i[a]);          i++;      }      return 0;  }  The Output of this Code is: 10 12 14  I have read through various books and websites but still i do not get how this code is working. I assumed the code will have a compilation error since i is not an array but somehow in this case it prints the above mentioned output. I experimented by passing pointers instead of the array and it still worked. It would be very kind of you to explain since my lecturer won't reply.


Use VPN except for some applications in Windows

I am a freelancer at Upwork. When I use Upwork's time tracker, if they detect me changing IP a lot, they'd think someone from another place is working using my account and violating their terms.  I am a Web Scraper Specialist, so sometimes I need VPN to work. How can I use VPN but exclude one application (Upwork Time Tracker) from being affected by that VPN? I use Windows 10.


flashplugin-installer vs. flashplugin-nonfree vs. adobe-flashplugin

When searching through Synaptic for flash player I always see the options to use "flashplugin-installer" or "flashplugin-nonfree" or "adobe-flashplugin".  Is there a reason to use one over the other?    I seem to be constantly running into problems with Flash player freezing crashing, mostly because of running too many flash apps at once (pandora/fantasy apps/youtube/etc). Does using one of these over the other have performance benefits?  Or am I confusing myself and it doesn't really matter as they're both the same?


Proof of exchange principle in set theory

How would one use the Axiom of Foundation (that every non-empty set has an $\in$-minimal element) to prove that for any two sets $x,y$ we can find a set $x'$ so that $x'$ and $y$ are disjoint and $x'$ and $x$ are in bijection?  I myself tried to construct $x$ recursively by doing the following: if $x$ and $y$ are disjoint, we are done; if not, take $z$ in $x \cap y$ and let $x_{1} = (x - \left\{z_{1}\right\} ) \cup \left\{y\right\}$. Now, the new intersection $x_{1} \cap y$ has size with $1$ less than the size of $x \cap y$ because $y \not \in y$ (by Axiom of Foundation) and so on (i.e. if $x_{1}$ and $y$ are not disjoint take $z_{2}$ in the intersection and let $x_{3} = (x_{1} - \left\{z_{2}\right\}) \cup \left\{\left\{y\right\}\right\}$. However, I don't think this works since we might have $y \in x$ and this messes up our bijection.  A detailed answer would be appreciated... (for me to get confortable with the basics) thanks


Recover files deleted from Windows 7 with no backup

I accidentally deleted important files, for which I do not have a backup.  My thesis files worth four years of sweat is gone and when I tried to go back to a "previous versions" I get the message:     There are no previous versions available   How can I recover them from a Windows 7 machine?


How can I solve $\int_{-\infty}^{+\infty}\mathrm{e}^{-(\alpha +\beta i)x^{2}}\mathrm{d}x$?

How can I solve this integral  $$\int_{-\infty}^{+\infty}\mathrm{e}^{-(\alpha +\beta i)x^{2}}\,\mathrm{d}x$$  knowing that  $$\int_{-\infty}^{+\infty}\mathrm{e}^{ix^{2}}\,\mathrm{d}x=\sqrt{\pi }\mathrm{e}^{i\pi /4}?$$  I have to use Cauchy's integral theorem and integrate over a circular section of $ \pi/4 $ rad.


I am using jQuery library in my visual force page, but I've faced a major problem when I tried to use tabs "apex:tabPanel".  <script src="{!$Resource.jQuery}"></script> <!-- If I delete this script the tabs work !! -->  <apex:tabPanel tabClass="activeTab" inactiveTabClass="inactiveTab">   <apex:tab label="Tab#1" id="tab1"></apex:tab>   <apex:tab label="Tab#2" id="tab2"></apex:tab> </apex:tabPanel>     I get a "JS" errors in the console when I try to click on any tab, but if I delete jQuery library it works. So I guess there is a conflict between jQuery and apex:tabPanel functionality.


Like many screen users I'm used to Ctrla, so on my machine I changed the binding to Ctrla, however, I wish to keep Ctrlb since on some machines it's the default and when sharing work with other people this can be very confusing.  I tried putting two lines in my .tmux.conf but only one of them will work.


Less generic generics? A possible solution for arithmetic in C# generics

Currently, generics in C# do not allow any sane way to perform arithmetic. There are awkward workarounds available, but none of them are very neat and all of them reduce performance. According to , an interface with arithmetic types is not possible to implement, and so one such workaround is suggested.     But what you could do is have your Matrix take as an argument a Calculator, and in Calculator, have a method called multiply. You go implement that and you pass it to the Matrix.   Why should I have to tell an advanced programming language how to add and multiply numbers? [Edited due to popular demand]  Why not simply allow a Generic to be restricted to a list of types?  Eg.  class Matrix<T> where T : int,long,float,double   The syntax could of course be different. But the compiler needs only to check that the type is on the list, and that the operators used work on all types, which should be much simpler than the apparently-too-difficult interface suggestion.  Are there any obvious reasons as to why this cannot be implemented?


Hello I am currently scraping information from online and putting it into a list however the elements are appearing as :   ['\n      Michael\n    ',  '\n      Elad\n    ',  '\n      Yair\n    ',   '\n      Liron\n    ',   '\n      Idan\n    ',   '\n      Tomer\n    ',   '\n      Ofer\n    ',   '\n      Asaf\n    ',   '\n      Tomer\n    ',   '\n      Ronit\n    ',   '\n      Guy\n    ',   '\n      Lior\n    ']   Is there a way to format the list to erase the line indentations and the white space?   Thank you


What is the origin of "Color me confused"?

I drowned in the search results of articles using "Color me confused" phrase.    What is its meaning and origin?


A5 booklet printing -- Title page and TOC are missing

I have a file bookletdemo.tex with the following code  \documentclass[12pt]{article} \usepackage[a5paper]{geometry} \usepackage{lipsum}  % this package is for creating filler text   \author{N.~N} \title{The booklet}  % \usepackage[print,1to1]{booklet} \nofiles  % \target{\magstep0}{297mm}{210mm}   \begin{document}  \maketitle  \tableofcontents  \section{Europe} \subsection{Berlin} \lipsum[4] \subsection{Paris} \lipsum[1-3] \subsection{Vienna} \lipsum[10] \subsection{Rome} \lipsum[15] \section{Africa} \lipsum[1-4] \subsection{Accra} \lipsum[5-8] \subsection{Johannesburg} \lipsum[9-11] \subsection{Casablanca} \lipsum[11-12] \lipsum[5-6] \section{Asia} \lipsum[1-4] \subsection{Tokyo} \lipsum[5-8] \subsection{Beijing} \lipsum[9-11] \subsection{Mumbai} \lipsum[11-12] \lipsum[5-6]  \end{document}   Fist I run  latex bookletdemo.tex    two times. The pdf formatting of the document with A5 pages is fine.  Then I uncomment  \usepackage[print,1to1]{booklet} \nofiles  \target{\magstep0}{297mm}{210mm}   and run      latex bookletdemo.tex    to create a booklet. It produces something which resembles a booklet but the title page and the TOC are missing.   How does an example which does this properly look like?  Reference


Communicate between two local Mac machines when one is on VPN?

I'd like to directly connect (be able to use ping/ssh or other common commands) two local Mac machines as one sometimes is on VPN. The two Mac normally are connected via a wireless router when none of them are on VPN. The VPN does not allow split tunnel. Once a Mac is on VPN, it can not access the other Mac behind the router.  The only solution I can think of is to directly connect them without using the wireless router. I'd prefer not to use a wired connection. However, it seems that this can not be done wirelessly, as via wireless a Mac can either connect to the wireless router or connect to a local network set up by the other Mac but not both.  Could anybody let me know a good way to solve this connection problem when one local Mac is on VPN? Thanks.


I can see /bin/bash folder but why the command throws error

Trying install the  on my Ubuntu. When running ./install.sh bash: ./install.sh: /bin/bash^M: bad interpreter: No such file or directory  it throws the error. I then cd into that folder and found the bash folder is there.  how to fix it?


How does Kant actually resolve the free will / empirical causality contradiction?

I'm reading through the Critique of Pure Reason and I'm stuck on the section Resolution of the cosmological idea of the totality of the derivation of occurrences in the world from their causes and likely some succeeding ones.  Here, Kant deals with the issue of the coexistence of free will and empirical causality, however I can't parse what he's trying to say for the life of me. It seems like he's running in a never ending circle of contradiction, whereby all events as appearances are fully determined through empirical causality, and that no series of events can be said to have an absolute beginning, and yet free will is exactly what begins a series of events.  He seems to try to resolve this by differentiating between an intelligible causality and a merely empirical one--but that's exactly what's bothering me. I can't understand what he means by "intelligible causality as opposed to the empirical one", and his writing on this matter is probably the most confused it's ever been in the Critique.  I've read that the central distinction here is time. Empirical causality exists within a time-series. Intelligible causality does not. What does that mean? Clearly there must be points of interaction where intelligible causality enters into the empirical one, can't it be said that a series of appearance-events had thus begun?  Note that I am specifically interested in this metaphysical side of the problem, I do know where he's getting at regarding the practical and regulative use reason has for the idea of freedom.


why i get NullPointerException when i try to visit member variables after force type convert?

I create a class Node which contains an int variable val When I try to get the val after I pop it from stack, the compiler throw a NullPointerException.  Does anyone knows how to fix this?  public class Node{   int val;   Node left;   Node right;   Node(int x) {val = x;} }   Node root = new Node(6); Stack s = new Stack(); s.push(root); Node node = (Node)s.pop(); System.out.println(node.val);


I am currently struggling to understand Section 11.9 in Tom Apostol's Introduction to Analytic Number Theory, where he talks about taking the logarithm of a Dirichlet series.  The idea is that we have some Dirichlet series $F(s) = \sum_{n=1}^\infty f_nn^{-s}$ with $f(1)\neq 0$ and   $F(s)$ is absolutely convergent  $F(s) \neq 0$   for any $s$ with $\mathfrak{R}(s)>\sigma_0$.  Apostol says that we can then always find some Dirichlet series $G(s)$ that is also absolutely convergent for $\mathfrak{R}(s)>\sigma_0$ and fulfils $e^{G(s)} = F(s)$ for any such $s$, and that $$G(s) = \ln f(1) + \sum_{n=2}^\infty \frac{(f' * f^{-1})(n)}{\ln n} n^{-s}$$ where $f^{-1}$ is the Dirichlet inverse of $f$ and $f'(n) = f(n) \ln n$, i.e. they correspond to the multiplicative inverse and the negative derivative of $F$.  However, if I am not missing anything here, I think all of this only works if $\sum_{n=1}^\infty f'(n) n^{-s}$ and $\sum_{n=1}^\infty f^{-1}(n) n^{-s}$ converge absolutely, but I don't see why they should, in general.


Mod_rewrite rule to redirect from a specific path to another is completely ignored

I need to redirect  to . The rule that I've created looks like this in ApacheRoot\conf\httpd.conf:  RewriteEngine On RewriteRule ^/?foo /WebFOO [R,L]   However, this approach doesn't work even though this rule is syntactically correct. Means I connect to  and get a 404 or the specific content for "/foo". Note: to test things out I've created a folder with a simple index.html in (htdocs/foo). This actually prevented the 404 of course but still the redirection did not take place.   The virtual-host portion looks like this and is beneath the mod-rewrite rule:   ServerName 1.2.3.4 <VirtualHost *:80>   ServerName 1.2.3.4:80   #Redirect permanent / https://1.2.3.4/ </VirtualHost>   Why is that redirection completely ignored? Am I able to check somehow whether the server at least recognizes the rule (no rewrite-entries so far in the error.log)?   Note: To be sure about the syntactical correctness of the rule I've also tested it with :    Not only this test worked fine but also things like /foo/index.html. It was correctly translated into /WebFOO/index.html.   Note: Enabling the verbose logging as suggested by one of a mod_rewrite canonical question's  is not suitable for apache 2.4:    The  states:      For more complex rules, use mod_rewrite's RewriteLog directive to log   activity to a file and set RewriteLogLevel 3    :       Since Apache httpd 2.4 mod_rewrite RewriteLog and RewriteLogLevel   directives has been completely replaced by the new per-module logging   configuration.      LogLevel alert rewrite:trace6    The :      RewriteLog      Those familiar with earlier versions of mod_rewrite will no doubt be   looking for the RewriteLog and RewriteLogLevel directives. This   functionality has been completely replaced by the new per-module   logging configuration mentioned above. To get just the   mod_rewrite-specific log messages, pipe the log file through grep:   tail -f error_log|fgrep '[rewrite:'    I don't have any [rewrite: entries in my ApacheRoot\logs\error.log


Suppose $\ker( \textsf{T}_{i+1} ) = \operatorname{im}( \textsf{T}_i )$. Show that $\sum_{i=1}^n (-1)^i \dim (\textsf{V}_i ) = 0$

Suppose $\textsf{T}_i :\textsf{V}_i \to \textsf{V}_{i+1}$ ($i=  0,\dots,n$) is a sequence of vector spaces such that  $$\ker( \textsf{T}_{i+1} ) = \operatorname{im}( \textsf{T}_i )$$ with $\textsf{V}_0 = \textsf{V}_{n+1} = \{0\}$. Show that $$\sum_{i=1}^n (-1)^i \dim (\textsf{V}_i ) = 0$$


For some reason, I have recently been having problems where my SanDisk 32GB Cruzer USB Flash Drive will mount as read-only. It was occasional at first, but now it is full blown and will not allow any writing. Here is the output of sudo hdparm /dev/sdb  /dev/sdb: SG_IO: bad/missing sense data, sb[]:  70 00 05 00 00 00 00 14 00 00 00 00 20 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  /dev/sdb:  multcount     =  0 (off)  readonly      =  0 (off)  readahead     = 256 (on)  geometry      = 30532/64/32, sectors = 62530624, start = 0  multcount     =  0 (off)   Yet if I try any task that involves writing to the drive- backup, touch /run/media/user/32GB/file it return an error about it being read-only. It is formatted as FAT32 (for windows compatability) and is around 1.5 years old.


Is this the meta site for SO or for the whole SE family?

Yes, I know there is this  question, but the tone of the answer seems to perpetuate the notion that other, non-IT SE sites don't actually matter.  For example, I asked  and was referred to  which was so full of C++ and PHP references that I failed to even see how it was related, even after a couple of readings.  If I come here for some honest Q&A about policies and procedures relevant to the whole family of SE sites and I'm met with a load "pure" SO jargon/examples I wonder why it is labelled as something different.  I'm aware of the history (that, In the beginning, there was Stack Overflow) but that doesn't justify the general state of confusion of this, MSO, site.


How do I delete the Edit Delete buttons suddenly showing above pictures?

All of a sudden when I insert a picture into a page, it shows an edit and a delete button above the image to the end user.  These buttons take you to the default page.  Also, now when I edit a page from the edit button at the top of each page and save, I get the following type of message after a lengthy wait.  Fatal error: Allowed memory size of 356515840 bytes exhausted (tried to allocate 523800 bytes) in /data/www/luna/sites/all/modules/token/token.module on line 767   I can edit and save if I select the page under Content.  See


How to reuse the same str_replace-like function pathauto is configured to?

Use case: Custom module to alter CONTENTTYPE_node_forms to hide some of many entity reference options when adding/editing a node. Then via a custom validate I set $form_state['values']['path']['pathauto'] = 0 and want to set the $form_state['values']['path']['alias'] depending on the parent item of the chosen entity reference since unfortunately Pathauto doesn't provide tokens for that. Finally the alias should look like that: parent-entity/entity/$form_state['input']['title'].  I builded that pattern by hand now and I'm asking me after I couldn't find anything, if I also have to rebuild the whole str_replace/preg_replace pattern of Pathauto or if there's a way to reuse the same pattern Pathauto is using for replacing spaces, special characters etc.?  Or is there maybe any other intelligent alternative to set a path alias pattern like that?


How do I parse a JSON map into an Apex Map?

I am trying to parse the following JSON format into a Object.  {   "info1": "blah blah",   "info2": "blah blah2",   "info3": 1391673663,   "info4": "blah4",   "info5": {     "AAA": 0.1,     "BBB": 0.3, .....   } }   But the problem is under [info5] list, name like "AAA", "BBB" and their related values are dynamic and always changing.   How should I make my Object to satisfy this kind of structure? I want to put those values into a Map if possible.  So that I can easily get "AAA" and its Related values.  Any input will be so helpful for me.


Back up not only games, but also game progress before flashing ROMS

I have a Galaxy S2 (GT-I9100) And I'm about to flash a custom rom on it. I've done it a bunch of times but what really irritates me is that I lose all progress made on the games that I have on my phone!  I backup the actual games and other applications using Astro file manager, but when I star my phone up after flashing a rom and re-install the game, I have lost all progress.  How does one backup a game, with game progress intact?  Thanks for any tips!


How can a shadow move faster than light?

So I understand that similar questions has been asked before. There is a specific aspect I don't understand which I don't think has been explained. If I shine a light on a surface and then I add a barrier, isn't there still a some photons remaining on the other side of the barrier which will still be travelling toward the same surface. Therefore, wouldn't the shadow moving across the surface be travelling at a slower speed than that of light. I've made a rough illustration of what I mean. (Sorry it's an MSPaint job).


What is the easiest way to order a / in jQuery?

I'm looking for some sample code that will sort the list items in an HTML list by alphabetical order.  Can anyone help?  Here is a sample list for people to work with:

apples

cats

bears


How to convert the elements of an array into a number ? Python

Let's say I have a NumPy array: x = np.array([1, 2, 3, 4, 5]).  How do I convert this array into the integer 12345?


I'm writing a program to compare different sorting algorithms speed. The majority of cases, I can begin each algorithms method with   long startTime = System.currentTimeMillis();   and end it with   long stopTime = System.currentTimeMillis(); long elapsedTime = stopTime - startTime; System.out.println(elapsedTime + " milliseconds");   However, because quick sort is recursive, this wont work as it'll print a time for every recursion, rather than the total elapsed time.  My Code  public static void quickSort(int[] arr, int low, int high) {  if (arr == null || arr.length == 0)   return;  if (low >= high)   return;  // pick the pivot int middle = low + (high - low) / 2; int pivot = arr[middle];  // make left < pivot and right > pivot int i = low, j = high; while (i <= j) {   while (arr[i] < pivot) {     i++;   }    while (arr[j] > pivot) {     j--;   }    if (i <= j) {     int temp = arr[i];     arr[i] = arr[j];     arr[j] = temp;     i++;     j--;   } }  // recursively sort two sub parts if (low < j)   quickSort(arr, low, j);  if (high > i)   quickSort(arr, i, high);  if ((low >= j) && (high <= i)) {     }   }   How can I make it so that it only runs "stopTime" the final iteration of the algorthim. Thanks


How to include multiple IF statements in one cell in Google Sheets

I am attempting to change the value of a cell in Google Sheets based on the value of an adjacent cell. This adjacent cell gets its value from the colour of the cell adjacent to it using the formula from  Quora answer. So the value of the cell should change based on the hex code which is obtained from the colour of the first cell. There are four possible hex values at the moment so I was trying to put four different IF statements in the same cell, so its value is changed based on this.   My first attempt led to a formula parse error:  =if((J2="#00ff00","Read"), if(j2="#ff0000", "Unread"), if(j2="#ff9900","In Progress"), if(j2="#000000", "Not Applicable"))   It is clear you cannot simply separate if statements with commas. Based on  Stack Overflow question I tried this code, with nested IF statements:  =if((J2="#00ff00","Read", if(j2="#ff0000", "Unread", if(j2="#ff9900","In Progress",if(j2="#000000", "Not Applicable")))))   This also leads to a formula parse error.   Is there any way I can simply include multiple IF statements in the same cell which will work for my code?


Energy of a photon seems to be $mv^2$, NOT $0.5mv^2$ like it should be

Obviously I must have made a mistake somewhere in my reasoning, but I can't see it.  Start with de Broglie: $$ P= \frac{h}{\lambda}$$ $$ h=P \lambda $$  Substitute into Einstein's energy equation for a photon (EDIT: read "particle" instead) without any potential fields or whatever.  $$E = h f$$ $$E = P \lambda f$$ $$E = mv^2 $$  But since this photon (particle) isn't in any potential fields, I would expect its energy to be just its kinetic energy - $0.5mv^2$ - instead.  What mistake did I make?


By L'Hôpital's rule, it gets $$\lim_{x\to 0}-\frac{\left(e^{(x+1)^{1/x}} (x+1)^{1/x}-e (x+1)^{e/x}\right) ((x+1) \log (x+1)-x)}{2x^3(1+x)},$$which becomes more complicated.  What could I do then?


What is difference between:    Why I am studying?  Why am I studying?


How can I complete the prerequisites for MS in Computer Science? 2019 application

I have gone through:  but this person had a lot of experience.  My Background: I am currently pursuing my bachelors in electrical engineering. I wish to pursue my Masters in Computer Science. I will graduate in 2019 (expected) with only 2 months of internship experience in Python (Data Science application).   Country of Residence: India  Countries of Interest for University Applications: US, Canada and EU.  Probable MS start date: Fall 2019 / 2020  I have noticed that there are prerequisites to get admitted to those programs. Specifically, I need to have completed courses in Data Structures, Algorithms, Operating Systems, Theory of Computation, Compilers and Computer Networks.   My undergraduate degree did have courses like C programming and OOPs, but nothing else. I took a computer course on Python at a local computer institute and interned during the vacation.   With my current qualifications I am unlikely to get any meaningful work in CS so I would like to use a masters degree to start a career in CS.  So here are my options to fulfill the prerequisites:-  1) PG Course in computer science (Expensive; only distance learning mode will work)  2) Computer Science courses on edX, Coursera  3) Professional certifications like CompTIA a+ / Network+ etc.   My major concern is whether Option 2 &/or 3 will be considered by admissions committees? These may showcase my aptitude for CS, but will I still have to take UG level courses before pursuing a Masters degree?


Print statement running before if statements

I am converting the English date into the Welsh date using a Java program but the if statements do not appear to run as the date does not change. What am I doing wrong?  I am new to Java and I have learnt Python and am now teaching myself Java. This English-to-Welsh date converter was a task I set myself in Python and I have now set it for Java.  Code:  import java.util.Scanner;  public class Main {     public static void main(String args[]){         System.out.println("What is the Date?:");         Scanner date = new Scanner (System.in);         String Date = date.next();         date.nextLine();         System.out.println("What Day is it?:");         Scanner day = new Scanner (System.in);         String Day = day.next();         day.nextLine();         System.out.println("What Month is it?:");         Scanner month = new Scanner (System.in);         String Month = month.next();         month.nextLine();         if (Day == "Monday"){             Day = "Dydd Llun";         }         if (Day == "Tuesday"){             Day = "Dydd Mawrth";         }         if (Day == "Wednesday"){             Day = "Dydd Mercher";         }         if (Day == "Thursday"){             Day = "Dydd Iau";         }         if (Day == "Friday"){             Day = "Dydd Gwener";         }         if (Day == "Saturday"){             Day = "Dydd Sadwrn";         }         if (Day == "Sunday"){             Day = "Dydd Sul";         }         if (Month == "January"){             Month = "Ionawr";         }         if (Month == "Febuary"){             Month = "Chwefror";         }         if (Month == "March"){             Month = "Mawrth";         }          if (Month == "April"){             Month = "Ebrill";         }         if (Month == "May"){             Month = "Mai";         }         if (Month == "June"){             Month = "Mehefin";         }         if (Month == "Jully"){             Month = "Gorffennaf";         }         if (Month == "August"){             Month = "Awst";         }         if (Month == "September"){             Month = "Medi";         }         if (Month == "October"){             Month = "Hydref";         }         if (Month == "November"){             Month = "Tachwedd";         }         if (Month == "December"){             Month = "Rhagfyr";         }         System.out.println(Date + " " + Day + " " + Month);     } }


Prove "Any open subset of $\Bbb R$ is an at most countable union of pairwise disjoint open intervals”.

Let $E$ be a nonempty open subset of $\Bbb R$. There is a collection $A$ of subsets of $\Bbb R$ satisfying the following:  $(i)$ Each element of $A$ is an open interval (possibly infinite) and any two distinct members of $A$ are disjoint; $(ii)$ $A$ is at most countable; $(iii)$ $E =\bigcup\limits_{G\in A}G$.   Prove that ”Any open subset of $\Bbb R$ is an at most countable union of pairwise disjoint open intervals”.   I don't know any structure theorems. I only have done a course on real analysis. Which dealt with compact sets and all.


A statistics problem (normal distribution)

If $X\sim  N(0, \sigma^2)$, how can I compute $\operatorname{Var}(X^2)$? Here is my idea... but I cannot get there. $$\operatorname{Var}(X^2) = E(X^4) - (E(X^2))^2$$


I have tried to read Hatcher's  book. He proved  Theorem 2.10: If two maps $f,g :X \to Y$ are homotopic, then they induce the same homomorphism $f_* = g_*:H_n(X) \to H_n(Y)$.  One can immediately obtain following corollaries using the dual version of prism operator described in Theorem 2.10 and some facts:  Corollary 1: If $f,g :X \to Y$ are homotopic, then $f_* = g_*:\tilde H_n(X) \to \tilde H_n(Y)$ for $n>0$.  Corollary 2: If $f,g :(X,A) \to (Y,B)$ are homotopic, then $f_* = g_*:H_n(X,A) \to H_n(Y,B)$.  Corollary 3: If $f,g :X \to Y$ are homotopic, then $f^* = g^*: H^n(X) \to H^n(Y)$.  Corollary 4: If $f,g :X \to Y$ are homotopic, then $f^* = g^*:\tilde H^n(X) \to \tilde H^n(Y)$ for $n>0$.  Corollary 5: If $f,g :(X,A) \to (Y,B)$ are homotopic, then $f^* = g^*:H^n(X,A) \to H^n(Y,B)$.  I wonder that how can we prove the following statements:  Corollary 6: If $f,g :X \to Y$ are homotopic, then $f_* = g_*:\tilde H_0(X) \to \tilde H_0(Y)$.  Corollary 7: If $f,g :X \to Y$ are homotopic, then $f_* = g_*:\tilde H^0(X) \to \tilde H^0(Y)$.  An attempt for Corollary 7 is  Proof of Corollary 7: By Universal Coefficient Theorem, we have $$\tilde H^0(X;G) \approx Hom(\tilde H_0(X),G).$$  Hence the result follows from the dualization of the proof Corollary 6.  Any help will be appreciated.


Specifically, why do some universities have a defined "graduate school" and associated "graduate faculty," with separate appointment process, and some do not, even when they offer many graduate programs?  What is the organizational and administrative thinking behind this?


Link with double-underscored word in URL renders incorrectly

While reviewing  I noticed that the URL that was posted as one of the answers looked weird to me:     leopard_9m2809a.dmg">   I clicked on the edit link to see if the user had perhaps posted some broken HTML, but all I found was a bare URL:     http://adcdownload.apple.com/iphone/iphone_sdk_3.1.3__final/iphone_sdk_3.1.3_with_xcode_3.1.4__leopard__9m2809a.dmg     Here's how the above URL renders currently:    (I'm assuming) it should look like this:      EDIT:  I wonder if it has anything to do with the double underscore that is causing the word "leopard" to appear italicized?  Let's try that out by removing the double underscore:    Aha! That must be it.


String answer1 = "yes"; if (answer1 == "yes") gives false. Why?

import java.util.Scanner;  public class NewClass {     public static void main(String[] args){          Scanner scanner = new Scanner(System.in);          System.out.println("Enter your name");         String name = scanner.nextLine();         System.out.println("Is "+ name + " really your name?");         String answer1 = scanner.nextLine();         if (answer1 == "yes"){         System.out.println("Alright ");         }else  {System.out.println("Liar!");     }     } }   It outputs Liar! even though I typed yes, so that answer1 equals yes. Why?


$$\begin{align} 2+2 &= 4 - \frac92 +\frac92\\ &= \sqrt{\left(4-\frac92\right)^2} +\frac92\\ &= \sqrt{16 -2\times4\times\frac92 +\left(\frac92\right)^2} + \frac92\\ &= \sqrt{16 -36 + \left(\frac92\right)^2} +\frac92\\ &= \sqrt {-20 +\left(\frac92\right)^2} + \frac92\\ &= \sqrt{25-45 +\left(\frac92\right)^2} +\frac92\\ &= \sqrt {5^2 -2\times5\times\frac92 + \left(\frac92\right) ^2} + \frac92\\ &= \sqrt {\left(5-\frac92\right)^2} +\frac92\\ &= 5 + \frac92 - \frac92 \\ &= 5\end{align}$$  Where did I go wrong


Char arrays filled with 0xCC after allocation

So after allocating char array in debugging windows I can see my array is filled with 0xCC. What does it mean? (-52 = 0xCC)


Commuting linear operators, one must be a polynomial of the other?

Let $\alpha$ and $\beta$ be linear operators on a vector space V. Suppose that $\alpha$ satisfies a non-zero polynomial. Prove that when V is $\alpha$- cyclic, we have $\alpha \circ \beta = \beta\circ\alpha,$ then $\beta = p(\alpha)$ for some polynomial p.  My approach was to let the $p'$ be the minimal polynomial that satisfies alpha. Then let $p'(\alpha\circ\beta) = p'(\beta\circ\alpha)$ but I can't seem to proceed from here.  I think the next step I want to show is that there is a polynomial that satisfies $\beta$, but after that I am just stuck


Why am I still losing reputation points on a questions that was already closed?

Possible Duplicate:          I asked a question . I explained that I am able to do these functions individually but I am looking for a way to combine them. One person understood and tried to answer. The question have then being voted down, I lost 12 reputation points on it. The question was then closed. After which I lost an additional 2 points. I believe that my question was fair enough that it should not have lost any points.


Should I use lemonade or soda pop when making a summer shandy?

So I am making a wheat beer and am adding lemons and oranges into the second stage of fermenting. I have heard through the beer vine that shandy's are lemonade and beer. Can I just add the lemonade or the soda pop before the bottling, and can it substitute the priming sugar? Also what would you recommend pop or lemonade?


Finding duplicates with first 12 characters of each line

I have file look like this...  abc100200300 abmen abc100200300 arcxi xyz200300300 aelmi   How do I print the lines that have duplicates (based on examining just the first 12 characters) to a separate file?  so in the separate file I should have  abc100200300 abmen abc100200300 arcxi


A good textbook on Introduction to Quantum Mechanics?

I'm starting my master in Physics. I've taken some Quantum classes before, but nothing as serious as this. I would like now to really go in detail with all the concepts of QM. My professor recommended us to buy Quantum Theory by David Bohm, but I think is a little bit hard for me. I'm looking for a textbook that explain the derivation of the mathematical formulas given. Some recommendations ?


Why does alert return an 'undefined' variable value?

I have a function that dynamically adds an input and dropdown box when a '+' sign is clicked. However, when the dropdown is changed, the alert returns undefined. Why does it?  jQuery(document).change(".marker-drop-down", function() {            alert(jQuery(this).attr("id"));      });  //functions function addInputBox() {         jQuery("#insert-question-inbox").append('

 <input class="question-input" type="text" id=question-'+i+' value=question-'+i+' /> <select id="question-'+i+'-drop-down" class="maker-drop-down"> <option>Select</option><option value="multiple-choice">Multiple Choice</option> <option value="select-all">Select all that apply</option></select>

');     i += 1;      }


I have following text:   response={\n  &quot;status&quot; : &quot;ERROR&quot;,\n &quot;message&quot; : &quot;<ERROR Mes$@ge can be anything>&quot;,\n &quot;responseMessage&quot; : &quot;Response&quot;,\n &quot;reason&quot; : &quot;REASON&quot;,\n  }   I want to extract this part from the above text -   &quot;message&quot; : &quot;<ERROR Mes$@ge can be anything>&quot;   Please note - error message can have any chars including special chars.  I have written following regex -   \&quot;message\&quot; \: \&quot;.+\&quot;,\\n   However, it extracts till the last occurrence of &quot;,\n.  I think somehow I should count the occurrences of &quot; in the regex.  Need help with the Regex.


I am developing a theme (which I am calling AsylumInfo) that gets built into a directory call /build and I have symlink from there to the wordpress setup on my computer.   When I use wp-admin I get the notification below. When I go to the theme chooser page and click 'update theme' button I see the following,.    When I click on the View version 1.13 link I get taken to . In other words Wordpress appears to be looking at the directory name, not the theme name, before trying to find a non-existent update online. By private theme has no link at all to this published theme and I want Wordpress to stop thinking that I need to upgrade.  How can I get rid of this?  I imagine one option is renaming /build to /asyluminfo, which I can do but can't be necessary. Another is set the version of my theme to something > 1.13, but that's also arbitrary.  I can't believe this hasn't happened to someone else before?


.htaccess - redirect non www to www and retain subdomains from redirecting

So, on my main domain 'domain.com' I created several subdomains from cPanel, like 'sub1.domain.com' and 'sub2.domain.com'. Their real location on server is in 'domain.com/sub1' and 'domain.com/sub2'.  Now, I want to redirect non www to www with .htaccess and this is what currently what i have:  <IfModule mod_rewrite.c> RewriteEngine On RewriteBase / RewriteCond %{HTTP_HOST} !^www\.domain\.com [NC] RewriteRule ^(.*) http://www.domain.com/$1 [L,R=301] </IfModule>   This works. When somebody enter domain.com it will be redirected to www.domain.com. However when somebody enter sub1.domain.com, he will be redirected to www.domain.com/sub1 - which I don't want, it needs to be in sub1.domain.com.  What shall I add in .htaccess file to accomplish this?


Why assign a subclass object to a superclass reference?

Animal is a superclass  Feline is a subclass of Animal  Cat is a subclass of Feline  Canine is a sublcass of Animal  Dog is a subclass of Canine  All of the classes have their own eat() method that outputs:  "(class) is eating"  I've already tried creating an array of Animals, looping through them, and calling the eat() method, which outputs the proper output for each given animal.  My question is, what does one gain by doing this:    Cat j = new Animal();   wouldn't Cat j = new Cat() do anything you need do regarding methods with Animal types, since it's already an animal through inheritance?   Edit: I'm sorry, I meant it the other way around--what does one gain by declaring:  Animal j = new Cat();   sorry!


Why were Golden Snitches made with flesh memories?

It seems like a lot of trouble to go to for something that we don't really need in Quidditch.


Calculating $\int_0^\infty \frac {\sin^2x}{x^2}dx$ using the Residue Theorem.

I am trying to compute the following integral using the Residue Theorem but am quite stuck: $$\int_0^\infty \frac{\sin^2x}{x^2}dx$$ I have tried applying Jordan's lemma, having written $\sin(x)$ as $\dfrac{\mathrm{e}^{ix}-\mathrm{e}^{-ix}}{2i}$, to not much avail. I have also tried using a rectangular integration path but it didn't get me far. I'd be grateful for an insightful advice.


Raggedright and uppercase title with \\ gives error

The following code gives this error:   ! Use of \@icentercr doesn't match its definition. <argument> \def   l.18 \maketitle  ?    The goal is to create a title like  FOO BAR BAZ FOO FOO BARBAZ FOO   from   \title{Foo bar\\baz foo foo\\barbaz foo}   so I can control the line breaks and get the text upper case. How can I get the code to work?  Here is the faulty code:  \documentclass{book} \usepackage[ngerman]{babel} \usepackage[utf8]{inputenc}  \title{Hello with\\crlf}  \makeatletter \renewcommand\maketitle{\begin{titlepage}%     \raggedright     {\MakeUppercase{\@title} \par}%   \end{titlepage}% } \makeatother   \begin{document} \maketitle \end{document}


Adding a jQuery Click function inside of a for loop

I'm going crazy. So I have a click function that creates a new div with unique classes and everything.   Inside all of them is a button (another click function labled .varibFixed) that hides and shows a div within the divs that are created with said click function.   My goal is to have that button work for all the new divs that are created. My code is listed below but it just does not work for the newly created divs - only the first div.   var interest = function () {     $('.varibFixed').click(function () {         for (var k = 1; k < i; k++) {             if ($(this).hasClass('fixed' + k)) {                 $('.Ffixed' + k).removeClass('interestOpt');                 $('.Ffixed' + k).addClass('showInt');                 $('.Fvariable' + k).removeClass('showInt');                 $('.Fvariable' + k).addClass('interestOpt');              } else if ($(this).hasClass('variable' + k)) {                 $('.Fvariable' + k).removeClass('interestOpt');                 $('.Fvariable' + k).addClass('showInt');                 $('.Ffixed' + k).removeClass('showInt');                 $('.Ffixed' + k).addClass('interestOpt');             }          }     }); };


I want to remove files from Google Drive, but I don't want them deleted from my hard drive. when I delete something from Google Drive it tells me that it will also be removed from my computer. I don't want that.


What are the differences between consumer grade SSDs and the much more expensive enterprise SSDs?

I am in need of a terabyte or so of storage space for Lucene indices on a testing server.  I'm having a hard time differentiating between disks like the  for about $450 vs  of dollars.  What concerns should I have regarding the 840 evo, and what should I be looking for?  This server will be used strictly for in-house testing purposes by our development team and will have to put up with periodic load testing.


One question regarding Basic Probability theory

If I throw a fair dice  $12$ times, the expected number of  $6$ is $2$  i.e $6$  is expected to appear  $2$ times when the dice is thrown $12$ times. But the probability of getting $6$ exactly $2$ times is ${12}\choose{2}$$(1/6)^{2} (5/6)^{10} $ which is less than $1$.   Now my question is How can you expect the face value six to appear for two times , when the possibility of that appearing  for two times is very low?  I am tying to give an analogy..If you are participating a game where you can win , lose or remain undecided.  How can you expect to win When  you know the possibility of winning the game is very low?  Can anyone please make me understand where I am getting wrong? I am really trying hard to understand.


Stack Exchange is my role-model for application development.  I've tried to learn as much as possible from the blog and podcasts, from thought process to design, architecture, convention, etc etc.  I'm just about to wrap my head around TDD and am curious about how the SE team approaches it.  Is there a methodology that all team members follow, or is it more developer-driven testing where you pick complex bits to unit test as needed, or is it more about catch-all integration testing once a piece of functionality is done, or... ?  Any input would be fantastic.


On the MSVC++ compiler, one can use the __int8, __int16, __int32 and similar types for integers with specific sizes. This is extremely useful for applications which need to work with low-level data structures like custom file formats, hardware control data structures and the like.  Is there a similar equivalent I can use on the GCC compiler?


So close yet so far Finding $\int \frac {\sec x \tan x}{3x+5} dx$

Cruising the old questions I came across juantheron asking for $\int \frac {\sec x\tan x}{3x+5}\,dx$ He tried using $(3x+5)^{-1}$ for $U$ and $\sec x \tan x$ for $dv$while integrating by parts.  below is his work.  How can I calculate $$ \int {\sec\left(x\right)\tan\left(x\right)  \over 3x + 5}\,{\rm d}x $$  My Try:: $\displaystyle \int \frac{1}{3x+5}\left(\sec x\tan x \right)\,\mathrm dx$  Now Using Integration by Parts::  We get  $$= \frac{1}{3x+5}\sec x +\int  \frac{3}{(3x+5)^2}\sec x\,\mathrm  dx$$  Here he hit his road block.   I tried the opposite tactic   Taking the other approach by parts.   let $$U= \sec x \tan x$$ then$$ du= \tan^2 x \sec x +\sec^3 x$$ and $$dv=(3x+5)^{-1}$$ then $$v=\frac 1 3 \ln(3x+5)$$ Thus $$\int \frac {\sec x \tan x}{3x+5}\,dx= \frac {\ln(3x+5)\sec x \tan x}{3} - \int \frac {\ln(3x+5) [\tan^2 x \sec x +\sec^3 x]}{3} \,dx$$    As you can see I got no further than he did.   So how many times do you have to complete integration by parts to get the integral of the original $\frac {\sec x \tan x}{3x+5} \, dx$ or is there a better way?


For the purposes of Magic Jar, does a monster with the Spellcasting special trait have class levels?

The spell magic jar says with regards to the creature who's body the caster is possessing:      If the target has any class levels, you can't use any of its class features.   The , which is usually worded like (emphasis mine):     The [monster] is an Xth-level spellcaster. Its spellcasting ability is [Ability] (spell save DC X, +X to hit with spell attacks). The [monster] has the following [class] spells prepared   Nothing directly seems to imply that such a monster has "class levels". Do they?   If not, and by extension the possessor would keep the Spellcasting special trait, would the caster of magic jar now have spells and spell slots from their Spellcasting class feature and from the monster's Spellcasting?


Show that $3n^4+3n^2+1$ is never a perfect square

I am looking for a proof for the fact that $3n^4+3n^2+1$ can never be a perfect square for a natural number $n>0$. I know for a fact that the statement must be true as it came up as one of the cases in a solution of the diophantine equation $y^2=x^3-1$ using the LTE lemma and, according to two different solutions I have come across, this equation has no solutions apart form $(x,y)=(1, 0)$. I have spent a considerable amount of time looking for a suitable attack strategy, however, I was not able to make any progress. Can anyone help?


"What is funny in people being injured?" vs "What is funny in peoples' being injured?"

Consider this as a question you asked from someone who thinks prank videos (stupid ones) are funny, especially those that show people getting hit severely or fall.  Which one of the following fits to the context?        What is funny in people being injured?   What is funny in people's being injured?      I guess both are grammatical and valid, but they convey different things.   First sentences asks about funny things about the injured people while I want to disparage their interest in such videos.  Considering the context, I think the second one should be used because that possessive apostrophe makes it clear what we are deprecating- laughing at the kind of hardship that people are facing in the video.    So, do you agree with me on this? Can I use the second sentence? Would you please tell me your opinions?


I run a Dell PowerEdge r710 server out of my house and I'm moving in with roommates in a couple weeks. Unfortunately I don't think they'll appreciate the ~70dBA it generates and I'm looking for ways to make it quieter.  I looked into replacing the fans with something less noisy, but unfortunately none of the quieter options move nearly enough air. The best one I found has been the , but at less than half the CFM (30.3 vs 67.85 on the stock  fans) it doesn't seem powerful enough.  I've also thought about putting  around the server to quiet it down, but acoustic panels also have the downside of acting like insulation, so heat could turn into an issue.


Existence of numbers, were they invented or discovered?

Fire is a good example of matter that human beings discovered; Fire has been a part of nature even before human beings found it and at some points and we have used it ever since we discovered the existence of fire.  Then, what about numbers?  Is 0 invented or discovered?   I see some postings that argue that 0 was "there" and we found it, and some say that there had been no concept of zero before we invented it.  However, for number pi, area of the circle has not been changed ever since creation of the universe. Then, is pi discovered?   Any opinions?


Minecraft peaceful mode: spawn hostile mobs, give them creative mode AI

I like playing in peaceful mode, as I feel that making something complex in peaceful is more fulfilling than in creative. However, making many things requires items dropped only by mobs. In creative mode, mobs spawn, but simply ignore you. You can still get mob drops by killing these effectively harmless mobs. Such a feature is not present in peaceful, as mobs do not spawn at all.  My question is, is it possible, through some mod, config file editing, in-game command, etc. to make mobs spawn in peaceful, but ignore the player as if the player is in creative? Any other method that preserves the mechanics of peaceful but adds this feature will also be appreciated.  The mods that I found that offer the solution are not up to date with the current version of Minecraft.  Thank you


Does $|a_n-a_{n+1}|\to 0$ imply $(a_n)$ is Cauchy?

My textbook has this problem as a kind of "concept check", where one is supposed to find a counterexample to the following statement:   A sequence of real numbers is cauchy iff.   $$ \forall \epsilon>0, \, \exists N \in \mathbb{N}, \, \forall n \geq N: |a_n-a_{n+1}|< \epsilon $$  I know that a sequence of real numbers is cauchy if   $$ \forall \epsilon>0, \, \exists N \in \mathbb{N}, \, \forall n,m \geq N: |a_n-a_m|< \epsilon $$   Finding such a counterexample is probably trivial, but I haven't been able to think of one.


What is the difference between == and === in php. I am unsure when to use both.  Updated note: So that it shows up in StackOverflow search, the difference between == and === is the same as the difference between != and !==.


Lie bracket for Lie algebra of $SO(n,m)$

How does one show that the bracket of elements in the Lie algebra of $SO(n,m)$ is given by  $$[J_{ab},J_{cd}]  ~=~ i(\eta_{ad} J_{bc} + \eta_{bc} J_{ad} - \eta_{ac} J_{bd} - \eta_{bd}J_{ac}),$$  where $\eta$ has is the definite symmetric form with signature $(n,m)$?


How to find a closed form solution of E[Max(X,Y)]?

There are 2 Random Variables X and Y.  X ~ N(a,b) and Y ~ N(c,d). X and Y are correlated with a correlation coefficient of p.  How do I find a closed form solution of E[MAX(X,Y)]?  Whichever way I look at it, I am not able to get rid of the randomness in the solution.  My sol:- E[MAX(X,Y)] = X* P(X>Y) + Y*P(Y>X)  But if I do this I will get an answer in terms of X and Y which are still Random.


Some mesh-edges in object-mode aren't displayed

So I have been extruding a cube to make a low poly banana and when I go from edit to object mode half the edges don't appear as well as half is dark.      I tried looking for an solution couldn't find one and its making me feel like I am doing something wrong so I decided to come here.


Is it possible to evaluate the following in a closed form? $$\int_{25\pi/4}^{53\pi/4} \frac{1}{(1+2^{\sin x})(1+2^{\cos x})}\,dx$$    I found the above definite integral at  but the solution is not given. I have tried various methods but none of them lead me to the solution, I am honestly out of ideas for this one.   Any help is appreciated. Thanks!


What Can I Use To Add A Custom Button Between Publish button and Move To Trash?

I want to insert a custom button between "Publish" button and "Move To Trash" link. What can I use to make this?  Here is a screenshot to make this clearer:    I know I can use jQuery, but I want to do it the wordpress way. May be there is a filter hook or something else for it?


Why $\int \frac{1}{x}$ is $\ln|x| + C$ not $\ln(x) + C$?

I am reading about indefinite integrals and I have a question regarding the use of the modulus in integrating $\frac{1}{x}$.   The book I am reading gives me the following explanation -    The book later gives no further explanation, which has left me confused.   I have found no reasonable explanation online, so I would like to ask why this is the case in integration.   What does the book cite as "difficulties that may arise"?


email address not appearing in user profile

I am using drupal 7 default user_register module, when a user registers with all the required fields, it successfully registers but when I click that user in people> tab his/her profile is displayed in which email is not appearing as you can see in the screen shot. Whereas when I clicked on edit link on the right side of that user email address exists.


Quick edit not recorded as such blocking vote change

A little background:  I do not know what the specifics are, but I've noticed that a quick edit after a post will often times not result in an edit being posted. It's as if there was no edit. Edit: According to Bart this amount of time is five minutes.  The problem:  A user made a really bad post (said that ~ in C# wrt integers was used for deconstruction). I down-voted said post. Post quickly disappeared (I guess poster realized they screwed up and took back the post). Later, I come back and see my down vote but the answer is now correct (that ~ is the bitwise complement operator). I try to get rid of my down vote because it is no longer appropriate. However, it has been about half an hour and there is no edit posted (presumably the poster made an edit within the non-posting edit window) so I can't take my vote back.  Suggested solution:  If post gets edited (even within the non-post edit window) mark all the votes as changeable. I would guess that this would either involve an update on a table of votes or adding a column for last edit time which is not bypassed by the grace period. I realize that this may be an entirely non-trivial change, but unless the non-posting of edits is somehow changed to make sure the edit was trivial it seems this is necessary.


How to have a yeast bread dough rise in a cool space

I saw an answer to a similar question and a gentleman named Joe said to use a radiator. I would relly appreciate more information about this. Thank you


How long does pancake batter last in the fridge?

I'm making a packet mix of pancake batter that doesn't lend itself to partial mixes - it's hard to split "1 egg" as an ingredient.  How long would pancake batter last in the fridge?  Even if it's a worst case of a day or two, I'd still like to know.


Gingrich was deposed as Speaker of the House after the election in 1998.   In the above sentence , can we write "deposed as a Speaker"? Or can it be "deposed as Speaker" only? Which one is correct? Please explain.


I've recently started learning Java and I was fooling around and I got confused on this.  String s1 = "Happy"; String s2 = "Happy"; String s3 = new String ("Happy");  boolean sameString; sameString = (s1 == s2); System.out.println("s1 == s2 is " + sameString); // This returns True.  sameString = (s1 == s3); System.out.println("s1 == s3 is " + sameString); // This returns False.   Can someone explain why this is so to me? Thanks!


Why do we not compile template implementation in a ".cpp.h" file?

While making a template linked list, rather than having the files list.h and list.cpp, we create list.h and list.cpp.h. The .cpp.h file contains the implementation for the linked list class. At the end of list.h, before the #ENDIF, we #include "list.cpp.h".   I understand that by making the .cpp file a header file we are able to avoid compiling it, but how does this work? We have needed to compile implementations that rely on using "template < class T >" in the past, so why do we not have to compile this implementation file?   Edit: My question was marked as a duplicate with a link to  , which I had already read. That question does not answer why the template implementation does not need to be compiled like a normal .cpp implementation file does. If we can avoid compiling implementations by making them header files, why do we not do that for every implementation? What are the downsides?   Does instantiating a template compile the code for each instance of that template? If my .cpp ever requires the use of a template in one of its functions, then why wouldn't I change it to a header file if it avoids this initial compilation?  I hope my question makes more sense.


Correct usage for "all you need is/are..."

What is the correct verb tense for the phrase "all you need is", when what follows is a plural?   All you need is paintbrushes and paint. All you need are paintbrushes and paint.   Or is neither incorrect?  Both forms sound funny to me.  Google shows an order of magnitude more hits for  than , but the latter still has ~500K hits, so it seems that both forms are in common use.  (You can also examples of both usages in Google's "News" search.)    Consider a related example:   All is good. All are good.   Both forms are correct, but have slightly different meanings/contexts.  The first is correct if "all" refers to "everything" (singular); the second is correct if "all" refers to an implied concrete set of things, as in "all (the widgets) are good".  This line of reasoning seems to imply the latter form is correct, since "paintbrushes" are concrete things.  (And yet that seems to be the less popular form in common usage, judging by Google hits).


how to block specific domains in hosts file?

I know hot to block single tumblr blog with   127.0.1.1 something.tumblr.com   but I want to block entire tumblr. I tried 127.0.1.1 tumblr.com but it's not working.  Is there a way to do this?


The stated  does not address solution in terms of $p, q, r,$ i.e. not in terms of the Viete's formula. My  approach is based on the viete's formula by finding the relation between the coefficients of a polynomial to sums and products of its roots.  If $\frac 1{a+b+c}= \frac 1a+ \frac 1b+ \frac 1c$, then show for odd $n$, $ \frac 1{a^n+b^n+c^n}=  \frac 1{a^n}+ \frac 1{b^n}+ \frac 1{c^n}$  Cannot establish the significance of odd $n$, i.e., why not applicable for even $n$.  Also, a simple approach is: $\frac 1{a+b+c}= \frac{ab+bc+ca}{abc}\implies abc = (ab+bc+ca)(a+b+c)$.  The two product terms are usually associated to a polynomial (as shown below) with $3$ roots: $a,b,c,$ having $-p=$ sum of roots $=a+b+c$, and $q=$ sum of product of roots two at a time$=ab+bc+ca$, and the single term for all $3$ roots $=-r= abc.$  So, $-r = -pq\implies r = pq$.    Derivation of polynomial with $3$ roots: Let $a,b,c$ be the roots of $x^3 + px^2 + qx + r = 0$. Then, writing the polynomial in terms of roots gives $(x - a)(x - b)(x -c)$.  $\therefore$ $x^3 + px^2 + qx + r = (x - a)(x - b)(x - c)$.  $= (x^2 - (a + b)x + ab)(x - c)$  $= x^3 - (a + b)\cdot x^2 + (ab)\cdot x - c\cdot x^2 + (a+b)c\cdot x - abc$  $= x^3 - (a + b +c) x^2 + (ab + bc + ca) x - abc$  $\therefore$ equating coefficients  (a) $a + b + c = -p$.  (b) $ab+ bc + ca = q$.  (c) $abc = -r$.    Unable to proceed further.  I want to add that the source has cryptic answer that has next step as : The required polynomial is : $f(x)= x^3 +px^2+qx+pq$. <-- This step stucks me.  The next one ones are easy: This implies $(x+p)(x^2+q)$.  As one root is $=-p$, so $a=-p= a+b+c\implies c=-b$.  So, $\frac 1{a^n+b^n+c^n} = \frac 1{a^n}=\frac 1{a^n+b^n-b^n}=\frac 1{a^n+b^n+c^n}$.   The last part uses odd $n$ property, but the stucking step is issue.


Proving that this function has the same value for all integers $\geq4$.

My teacher gave us this question: A function $f$ has the property $$f(x+y) = f(xy)   $$ $$\forall x, y\geq4; x,y\epsilon Z$$ $$f(8)=9$$ Find $f(9)$. I know the solution to this question. $9=f(8) = f(4+4) = f(16)=f(8+8)=f(64)=f(16\cdot4)=f(20)=f(4\cdot5)=f(9)=9$ But I tried this for other values and everytime it came $9$. I think this will be true for every integer $\geq 4$. Intuition tells me that I can reach to any such integer from any such other integer by performing those operations.  Is the function $9$ for every integer $\geq 4$? If so, what would be its rigorous proof? I think it may need some number theory. Edit: I realized that if my assumption is true, it is only possible for $n\geq8$.


"One in 5 people is" OR "one in 5 people are"

Which of the following is correct:        One in 5 people in that area are Chinese    One in 5 people in that area is a Chinese       I am confused as different resources provide a different answer.  One of the resources says that people is not the subject of the sentence. One is the subject and in 5 people is a prepositional phrase. Since “one” is singular, therefore the correct usage is “One in 5 people in that area is a Chinese.”   However, I am not convinced with this argument. I have found the other usage almost everywhere else.


This is just the simplest of the attempts made. Hopefully there are clues in there that someone can follow.  On Ubuntu 16.04, 64 bit:  roger@roger-desktop:~$ sudo apt-get install --reinstall ttf-mscorefonts-installer [sudo] password for roger: Reading package lists... Done Building dependency tree Reading state information... Done 0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 0 not upgraded. Need to get 0 B/29.5 kB of archives. After this operation, 0 B of additional disk space will be used. N: Ignoring file '50unattended-upgrades.ucf-old' in directory '/etc/apt/apt.conf.d/' as it has an invalid filename extension Preconfiguring packages ... (Reading database ... 329314 files and directories currently installed.) Preparing to unpack .../ttf-mscorefonts-installer_3.4+nmu1ubuntu2_all.deb ... mscorefonts-eula license has already been accepted Unpacking ttf-mscorefonts-installer (3.4+nmu1ubuntu2) over (3.4+nmu1ubuntu2) ... Processing triggers for fontconfig (2.11.94-0ubuntu1.1) ... Processing triggers for update-notifier-common (3.168.2) ... ttf-mscorefonts-installer: processing... ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/andale32.exe Get:1 http://downloads.sourceforge.net/corefonts/andale32.exe [198 kB] Fetched 198 kB in 2s (66.5 kB/s) N: Ignoring file '50unattended-upgrades.ucf-old' in directory '/etc/apt/apt.conf.d/' as it has an invalid filename extension W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/andale32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/arial32.exe Err:1 http://downloads.sourceforge.net/corefonts/arial32.exe The HTTP server sent an invalid Content-Range header N: Ignoring file '50unattended-upgrades.ucf-old' in directory '/etc/apt/apt.conf.d/' as it has an invalid filename extension W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/arial32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) E: Failed to fetch https://cytranet.dl.sourceforge.net/.../corefonts/the fonts/final/arial32.exe The HTTP server sent an invalid Content-Range header  E: Download Failed Setting up ttf-mscorefonts-installer (3.4+nmu1ubuntu2) ... N: Ignoring file '50unattended-upgrades.ucf-old' in directory '/etc/apt/apt.conf.d/' as it has an invalid filename extension roger@roger-desktop:~$


I've just downloaded ubuntu and transferred it to a memory stick. I pressed restart as per guide and the computer restarted -- in Windows10. It seems like an impasse. Can anyone advise?


Is it OK to ignore image title attributes when it comes to SEO?

I've  that it's OK to ignore the image title, but not the alt field from a SEO perspective.  However, the SEO expert in the company insist it's highly required for SEO.  Who is right?  Is there any reference or documentation for it?


I'm trying to split text in a JTextArea using a regex to split the String by \n However, this does not work and I also tried by \r\n|\r|n and many other combination of regexes. Code:  public void insertUpdate(DocumentEvent e) {     String split[], docStr = null;     Document textAreaDoc = (Document)e.getDocument();      try {         docStr = textAreaDoc.getText(textAreaDoc.getStartPosition().getOffset(), textAreaDoc.getEndPosition().getOffset());     } catch (BadLocationException e1) {         // TODO Auto-generated catch block         e1.printStackTrace();     }      split = docStr.split("\\n"); }


How can I remove python 2.7 after installing python 3.3?

I have successfully installed python 3.3 on Ubuntu 12.10. Since I don’t need multiple versions of python, I want to remove the existing python 2.7. When I try to do that, using  sudo apt-get remove python2.7   Ubuntu warns me that there are tons of system dependent components which will also be removed. It looks really scary.  So, is there a way to remove python 2.7 without removing the system dependent components, or can I direct those dependents to use python 3.3?


If $(X,\mathcal {B},\mu)$ and $(X,\mathcal{B}'\mu')$ are measure spaces on the same set $X$, we say that the latter is a refinement  of the former if $\mathcal{B}\subset \mathcal{B}'$ and $\mu'\downharpoonright_\mathcal{B}=\mu$.   Any measure space admits a refinement to a complete measure space via , and the resulting measure space is the coarsest refinement of the original measure space to a complete measure space. This implies that it is possible for a complete measure space to admit a further refinement, and such an example can be found in .   Now the  Lebesgue measure space $(\mathbb{R}^d,\mathcal{L}(\mathbb{R}^d),m_d)$ is complete; but unlike the above example above, many subsets of $\mathbb{R}^d$ are Lebesgue measurable and I was wondering if it admits a further refinement. Does it?


Complete classification of the groups for which converse of Lagrange's Theorem holds

It is known that the converse of  isn't true in general. More precisely it is known that the following proposition:  If $G$ is a finite group of order $n$ and $m\mid n$ then there exists a subgroup $H$ of $G$ such that $\operatorname{order}(H)=m$.  isn't true for all finite groups $G$. My questions are:   For which groups $G$ does the converse of Lagrange's Theorem (as stated above) hold? More precisely, if $G$ is a group for which the converse of Lagrange's Theorem as I mentioned above holds then what properties must $G$ satisfy?  If there is no complete classification of such $G$s then can someone give me references to works by other mathematicians where they try to give at least a partial classification of these $G$s?    Please note that I am not interested in knowing a complete classification of the groups for which a partial converse holds ( does the job in some sense). I want to know a complete classification of the groups for which the converse of Lagrange's Theorem as I mentioned above holds.


Get list of installed applications from Windows command line

I once saw a guy run a command and got a list of all installed applications on his computer. How do I do this?   I would like a list of my currently installed applications. I believe he used  somehow.


Can I have dynamic custom variables in Word?

I'm basically trying to create a variable in a document, let's say the name of a person, so that I can change the value in a single place and it updates through the whole document.  I've been reading about Fields and about a DOCVARIABLE, but I can't find where to edit the value (right clic didn't show an "edit" option). I'm using Word 2011 for Mac (that's what we have at work right now) so I'm wondering whether this version of Word is just not intuitive, or I cannot have variables like that in Word and I'm misinterpreting the documentation.  This is what I intend to do:  Hello, my name is PERSON_NAME, I have PERSON_AGE years old.   You get the idea.  PS: We actually want to modify the variables' values from our app, rather than from Word itself, kind of like injecting values to a .*docx file.


Notepad++, take it easy on nonexistent folder

I am using notepad++ constantly. We have a lan where we store things. However, most of our clients have vpns which I constantly have to connect to and lose my lan access temporarily. When I do this, every file that is open in notepad++ takes an annoying half-minute at a seemingly "not responding" state, after which it asks if I should keep a copy of it open.  Is there some way to tell it to ignore the accessibility of its storage folder until I hit save?


Merge multiple meshes into one single mesh?

Is there any addon that will allow me to merge multiple different meshes into one solid mesh?  I've spent a great deal of time constructing a fancy window frame, but I made it out of multiple individual meshes.


want to search sting and need part of string  example.txt:  CREATE MULTISET TABLE $$ENV$$_TEMP_ESM.EMPASGMTAMPTMPRTRSE ,NO FALLBACK , NO BEFORE JOURNAL, NO AFTER JOURNAL, CHECKSUM = DEFAULT, DEFAULT MERGEBLOCKADSRATIO   its should find $$ENV$$_TEMP_ESM.EMPASGMTAMPTMPRTRSE and i need only TEMP_ESM.EMPASGMTAMPTMPRTRSE or after $$ENV$$_ in what ever string is there need that string, i don't want to print next string


import java.sql.*;  public class MyClass {     public Connection LetConnect(){         Connection conn=null;         String url,username=null ,password=null;         url="jdbc:sqlserver://localhost\\SQLExpress;databaseName=Test";         username="sa";         password="******";           try {             Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");             conn=DriverManager.getConnection(url,username,password);             System.out.println("Connected");         } catch (SQLException | ClassNotFoundException e){             e.printStackTrace();         }       return conn;     }      public static  void FetchData(){         Connection conn= LetConnect();         String sql = "select * from employee";         try {             Statement st=conn.createStatement();             ResultSet rs=st.executeQuery(sql);             while(rs.next()){                 System.out.println(rs.getString(1)+" "+rs.getString(2));             }         } catch (SQLException e){                 e.printStackTrace();         }     }      public static void main(String[] args){         MyClass.LetConnect();         MyClass.FetchData();     } }  I have the code above I keep getting this error error: non-static method LetConnect() cannot be referenced from a static context Connection conn= LetConnect(); not sure what it means


When establishing community, the actions of visitors such as self registration is not captured by default  How to setup debug logs for guest user of communities is important to trouble shoot the issues


javascript - period changed to underscore

I'm trying to make an ajax call which contains the following example parameter  farms.company_id=1   but when received by PHP it has been changed to   farms_company_id=1   What's the best way to prevent this?


Change the page size in a beamer presentation

I am trying to make a set of flashcards using beamer. I want the page size to be well suited for my phone. But I am not able to change the page size of the beamer presentation. Can you suggest something?


Magantism vs Gravity with Special Relativity

According to relativity, gravity is not a force, and an item doesn't fall, so much as travel through a straight line (geodesic) through space time which is warped.   Because the geodesics converge, it gives the impressions that items fall.   This I understand, but I'm having trouble relating this to magnetism. Like gravity, it would make sense that magnetism isn't some magical invisible force that spans space pulling items together, but rather that it is another warpage of space-time.   This warpage must be different from gravity.  For one, similar polls repel each other (thus the geodesics of similar polls must diverge rather than converge).   That's not hard to fathom.   But here's where I'm really getting confused.   Unlike gravity, magnets only attract certain types of elements (iron, etc), whereas it does not effect things like glass, etc.   So the question is why do some types objects respect this 'warpage', whereas others do not?   How does charge relate to the geodesics of space-time?


Diminishing returns / non-linear reputation from “great” answers

Over time I realized a very annoying property of the Stack Overflow reputation system: Easy answers to popular question are rewarded with a lot more reputation points than actually great answers. In case anybody actually needs examples for this, here are two examples from :   gained me 420 rep, I invested 2 minutes writing it, and it only was a wild guess.   took me about an hour for the research and the math and gained me 40 rep.  Now I know that you are bound to get more rep for answers that are useful to more people, and I'd say that's fine. But the current situation is quite extreme: 30% of my reputation is from 5 of my 330 answers, and they are definitely far from being my best ones.  A final example that is not from my profile, but more extreme: Do you really think  is worth 40000 reputation?  My proposition to improve that situation would be to make the reputation gain from a single answer non-linear, maybe even have it capped at a certain point. I'm not sure on how that non-linear function should look exactly, and would leave good proposals for that to users with more experience than me.


Is it possible for one to triple boot three linux distros or (2 distros together with windows)?


What is the value of $$a/b/c,$$  for $a,b,c>0$?  Is it $ac/b$ or $a/bc$?  I get confused about this when I was studying wireless communications. The unit of the spectral efficiency is defined as $bit/second/Hz$.    if it is $ac/b$ then the unit of spectral efficiency will be $bit Hz/second$ which is $bit/second^2$; and  if it is $a/bc$ then I will have $bit/secondHz$ so it is simply $bit$.    Hence, I guess  $$a/b/c=a/bc.$$  But that's not true, isn't it?


Test class for Visualforce page with clone funcationality

I just a small help in understanding how to write a Test class for an std controller which performs a custom clone Functionality.  I have 2 questions 1. Is it necessary to write the Test class for the Lead std controller as I used it? 2. If that is the case to write case how can we write a Test class for Clone Functionality  Note: Why I'm using vf page rather than javascript URL hack the fields which we are trying to clone are Read-only for some profiles. In order to overcome, I have gone through page  Thanks prior for sharing your Knowledge  This is my Class:  public class customcloneLead{ private lead l; public customcloneLead(apexpages.standardcontroller std){ } public void clonelead(){ lead l1 = new lead(); l1 =l.clone(); insert l1; } }   This is my Test class can anyone help?  @isTest  public class customcloneLead {  static testMethod void clonelead()   {  Lead testLead = new Lead();  testLead.LastName='Test lead';  insert testLead;   Test.StartTest();     PageReference pageRef = Page.Customclone;   pageRef.getParameters().put('id',String.valueOf(testLead.Id));   Test.setCurrentPage(pageRef);     myController customclone = new customclone(new Apexpages.StandardController(SC));   Customclone.save();   //testAccPlan.save(); call all your function here  Test.StopTest();  } }      Invalid type: myController at line 16 column 3:   This is the error i'm facing


I noticed that I lost 40 reputation points on Stack Overflow today. I checked my reputation history and this is the reason it gave me:     -10   19 mins ago     removed     User was removed      -30   19 mins ago     removed     Where is Visual Studio Express?   I did answer a question about where Visual Studio was located about a week or so ago, but I can't find it now.   I'm guessing that the original person who asked the question deleted his account and so all his questions got deleted as well, but why remove the reputation on the answer?


Split a string similar to how Windows does for command line arguments

How does the OS break up command line arguments into an array?  I have a custom interpreter for an application that takes a hideously large number of arguments in complex combinations. I absolutely do not want to use the third-party solutions out there. I have a map set up that allows me to parse and generate these parameters.  While writing unit tests, I would like to take a generated string and split it exactly the way the OS does. I could launch a process with the generated string but I don't want to do that and pollute the unit tests.  Surely Windows must have a function it uses to do this before firing up the executable. I assume that's why we can simply pop the argument array reference off the stack in our entry point.


Why are the fundamental and anti-fundamental representation in $\text{SL}(2,\mathbb{C})$ not equivalent?

I am currently learning group theory and I learnt that the fundamental representation and the anti-fundamental representation of $\text{SL}(2,\mathbb{C})$, $2 \times 2$ matrix with determinant of $1$, are not equivalent.  This means that no similarity transformation can map one of them to the other.  My professor gave an explanation (on the 2nd last paragraph on page 75 of the following document ) but I don't see how the difference in the signs in the exponent imply that the representations are inequivalent.  Can anyone please explain the explanation of my professor, or perhaps give another explanation?


Any two matrices M and N which have the same characteristic and minimal polynomial are similar ?   Is there any easier way to explain ?  I tried as M and N have same Jordan forms. So let Jordan form J of M implies  J = P^-1MP and Jordan form K of N give K = Q^-1NQ & J=K gives after solving N = R^-1MR where R = PQ^-1. Gives M and N are similar.


An equality involving the mean value property

I am trying to establish that  $$\frac2{\pi}\int_0^{2\pi} f(e^{i\theta})\cos^2\left(\frac{\theta}{2}\right)\;\mathrm d\theta=2f(0)+f^\prime(0)$$  for $f$ analytic on $|z| < R,\; R > 1$  I think I am making a mistake somewhere, please point it out to me.Here's what I've done unsing the mean value property and Cauchy's integral formula:  $$2f(0)+f'(0)=2(\frac1{2\pi}\int_0^{2\pi} f(e^{i\theta})d\theta + \frac1{2\pi i}\int_0^{2\pi}\frac{f(e^{i\theta})ie^{i\theta}}{e^{i2\theta}}=\frac{1}{\pi}\int_0^{2\pi} f(e^{i\theta})d\theta\frac1{2\pi}\int_0^{2\pi}\frac{f(e^{i\theta})}{e^{i\theta}}\quad\text{(1)}$$  But when I develop the expression $\frac2{\pi}\int_0^{2\pi} f(e^{i\theta})\cos^2(\frac{\theta}{2}) d\theta$ I get:  $$\frac1{\pi}\int_0^{2\pi} f(e^{i\theta})d\theta+\frac1{2\pi}\int_0^{2\pi}f(e^{i\theta})[{e^{i\theta}}+e^{i-\theta}]d\theta \quad\text{(2)}$$  The second integral in (1) differs from the second integral in (2). Thanks.


Is there any way to configure a computer to login automatically at bootup and then IMMEDIATELY switch users? The purpose is to trigger the profile loading process for the assumed user so that when they go to login, their profile loads instantaneously. Yet, the immediate user switch means that the login password is still required before any actual use.   A few of the attempts I have made require storing the password in plain-text for the system to use. Needless to say that is undesireable.  I have been looking for this solution for years; if anyone knows of a better solution to skinning this cat I am all ears.  EDIT: tsdiscon command will Lock the workstation.


How to analyze a small matrix to discover associations between cases and variables and the main factors underlyining the variables?

I would like to analyze a small matrix N (8 cases) x M (6 variables) whose values are the number of responses each case get on the different variables. These values have a very different scale because each case had a very different exposure, thus the number of responses are cleary very different in size. My aim is to find the distinctive characteristics (the "profiles" we can say) of each case with regard to the variables, and comparing the analysis results with a theoretical typology.   My first approach was to calculate the proportion for each case in order to normalize the values in a comparable scale (after this step I ended up with a matrix N x M containing proportions, with each row that adds up to 1) and then apply a Principal Component Analysis (PCA) in order to discover the most characteristic relations that link the cases to the variables, also discovering the main factors underlying the variables, which I try to interpret with the aid of my theoretical typology.  I already discovered that proportions are not appropriate for PCA analysis, but there are also "robust" PCA to analyze "compositional data" (the proportions). However, I am not specifically trained in statistics, and I am sure that there is some better and more correct approach to use for this case.   You can find   Can someone help me? Thanks


Can you extend your stay after entering the US under ESTA/VWP?

I had an old friend come to visit me in USA. He is retired and 65 years old. He came over on ESTA, but now would like to stay on longer. How can he stay here without having to travel all the way back to Germany and returning again?


Were or was, the majority of people concerned?

I have checked the possible duplicates which flagged up on this and I have attempted research with no conclusion. ELU is my final port of call.  I wrote, on another forum of Stack Exchange :     'the majority of people was concerned about . . .'   And I have just altered it to :     'the majority of people were concerned . . '   and I am now in a state of conflict so great that I cannot eat my breakfast.  Can you help ?


I need to draw a 3d isometric grid/lattice using tikz that is not visually confusing. It needs to be at least 6x6x6 but possibly bigger. I sort of would like to have it fade into the background or contracts in size as it goes into the screen. I will put small text nodes at each coordinate. For any example dots will suffice.  It is analogous to  except in 3D. The main issue is somehow figuring out how to make sure it is easily seen in 3D.


Is it possible to do a PhD with a Professor Emeritus?

The professor I want to work with for my PhD has recently changed status to Professor Emeritus. Would it still, in principle, be possible to do my PhD under his supervision or this just not possible?  Could I just email him and ask whether he still supervises PhD dissertations?   Or this regarded rude? I am not sure what exactly it means to be Emeritus I am afraid. How would I go about this?


How to show that $\mathbb{Q}$ is not $G_\delta$

I read a section of a book and it made mention of the set of rationals not being a $G_\delta$. However, it gave no proof. I read on  about using contradiction, but it made use of the Baire category theorem, which is unfamiliar to me. I was wondering if anyone could offer me a different proof; perhaps using the fact that the complement of $G_\delta$ is $F_\sigma$.  Thanks.


There used to be an option in Notepad++ that when you save a file, it showed a green vertical bar on the left, and when you make any change, it turns yellow. This behavior is in Visual Studio and SQL Management Studio (example below).  How can I turn this feature on in Notepad++?    I know that the disk icon on the header, next to file name on the title bar, turns red for unsaved files and blue for saved ones (and grey for read-only files). But I'm looking for this feature so I can exactly know where the changes were made.  Thanks.


Encourage users to update accepted answers when significantly outscored

Stack overflow is about getting high quality answers quickly.  The way that answers are sorted is intended to help realize that goal.  However, occasionally low quality answers find themselves on the top, when an answer is accepted, but later turns out to be unsupported by the community at large.  For example, the accepted answer to  has -4, while the highest scoring answer has a score of 19.  Without even looking at the contents of the responses, it's probably the case that the information in the accepted answer is dangerously incorrect while the most valuable info for future travelers is hidden further down.  This can amount to a lot of noise before finding value:    In a lot of cases, this happens when a one time user accepts an answer and then leaves, never to be seen of again.  This has its own set of issues addressed in other questions.  However, users who are still active are well primed to help improve answer quality, but currently have no one of knowing that their accepted answer has become dated.  In this particular case, the asker is still an active SO participant:    If prompted, they might be so inclined to revisit their question.  We don't need to pressure people into always accepting the highest voted answer, but in extreme cases they can help improve quality answer visibility without undermining the current sorting system that places the accepted answer at the top.  This would address something similar to what is currently being handled with the reminder:     Have you considered accepting an answer or starting a bounty for this question?   A good threshold might be sending a reminder to the question owner whenever the  badge is earned on a given question.  If they dismiss it, they don't need to be reminded again, but it's a good opportunity to allow active users to reconsider accepted answers that might have become incorrect.  Related to:


I was trying to configure the kernel and I got the following error. Can somebody please tell me what I should do?  root@nitr-desktop:/usr/src/linux# make menuconfig  *** Unable to find the ncurses libraries or the  *** required header files.  *** 'make menuconfig' requires the ncurses libraries.  ***   *** Install ncurses (ncurses-devel) and try again.  ***  make[1]: *** [scripts/kconfig/dochecklxdialog] Error 1 make: *** [menuconfig] Error 2


How many elements are in the quotient ring $\frac{\mathbb Z_3[x]}{\langle 2x^3+ x+1\rangle} $

How many elements are in the quotient ring $\displaystyle \frac{\mathbb Z_3[x]}{\langle 2x^3+ x+1\rangle}$ ?  I guess I should be using the division algorithm but I'm stuck on how to figure it out.


Possible Duplicate:          Should company names be followed by "has" or "have"? It depends on whether a company is treated as a singular proper-noun:     Samsung has gotten itself in a lot of trouble recently.   Or plural proper-noun:     Samsung have stated they don't imitate cooler products.   Are both acceptable?


findstr DOS Command's multiple string argument

findstr /v "black"  File1.txt   Above DOS command will display content of 'File1.txt' which are not matching string "black".  How to modify this command , if I need to filter words "black" and "white" ?


Does homeopathic or herbal treatment of cancer have any scientific recognition?

Even though we have a very high tech society, cancer is still a serious issue. We humans still are not entirely capable of fighting cancer.   Radiation and chemotherapy are still considered the best methods for treating it and frequently, even these don't work. And, as for this disease, it is a phenomenon of uncontrolled cell growth that has lead to the death of many people. Within these main two treatments, there is plenty of controversy surrounding applying radiation and chemo in a proper sequence.   However, there are also some different methods known and available on the market to treat cancer. Among them, homeopathic and herbal treatments are the most common. So, my question is, do they really work and is there any scientific evidence of that?  If yes then what is it?


Why can I not have a static object in a class?

Referring to the following:  class A { ... };  class B  {     static A a; // this fails     ...     static A& getA() { static A a; return a; } // this works     ... }; ... B b; b.a  <-- gives error: undefined reference to B::a   Why can I not have a static A in class B, but it is fine to return it from a method?  [edit] Just something curious:  struct C {     static const int x = 5; };  int main() {     int k = +C::x;     std::cout << "k = " << k << "\n";     return 0; }  output: k = 5   C::x is not defined in implementation-scope, neither is there an instance of C, and yet, with the unary + C::x is accessible ... !?


I'm developing a level-based app, and I want to be able to save the user's level number (1, 2, 3 etc..) and then when the app starts get the level number and do something with it. How can I do it?


Why do I get a ‘Remote Management’ step when installing High Sierra?

I got a 2015 MacBook Pro from eBay. I’m trying to install Sierra from scratch (after completely formatting the SSD) but I get this strange extra step (although the install USB is vanilla and done using Apple’s own bootable usb tool) that I can’t pass (pressing continue asks me to connect to a IBM private network, which I obviously can’t do)  Does anyone have any info about this. Where is this MacBook comming from? How can I disable this remote management step? Is this a custom firmwere, or where does this come from?


When and how did "pretty" enter English as an intensifying adverb?

Today I saw an idiomatic road sign: "Pretty Muddy". I found this lack of strict English on a road sign unusual (on par with my "Dead Slow" official speed limit sign in Leeds, pic below), but as it turned out it's a charity race and the signs were merely directions.  This got me thinking however, how do words like "pretty" and "dead" as   end up in English? Taking "pretty" as an example, when did this first appear?     I wonder how fast you have to be going before they stop you. How would this hold up in court?


Looking for a word to describe a person who lies/invents stories to elicit sympathy to manipulate others and further their own advancement

I am looking for the right word(s) to describe a person who lies and invents stories/scenarios to elicit sympathy in order to manipulate and further their own advancement at the cost of others.  Think along the lines of a psychopathic social climber, consumed by bitterness. Highly vindictive and vengeful due to an invented notion of unrequited love. Someone who has taken a twisted private fantasy and used it to try and gain both attention and allies against their perceived rival, regardless of that person's actual innocence. Thanks in advance for any input.


How to check OS and version using a Linux command

What is the Linux command to check the server OS and its version?  I am connected to the server using shell.


Why does the following algorithm print random string of characters instead of an array?

Here is my homework:     Write a program which does the following: It returns an integer array arr2 of length n whose first k elements are the same as the first k elements of arr, and whose remaining elements consist of repeating blocks of the first k elements. You can assume array arr has at least k elements. The function should return null if either k or n is not positive.      Examples:         fill({1,2,3,5, 9, 12,2,         1},         3, 10) returns {1,2,3,1,2,3,1,2,3,1}.         fill({4, 2, 3,         12}, 1, 5) returns {4, 4, 4, 4, 4}.         fill({2, 6, 9, 0, 3},         0, 4) returns null.    Here is my code:  public static void main (String[] args){     int [] result = fill(new int[]{1, 2, 3, 5, 9, 12, 2, 1}, 3, 10);     System.out.println(result); }      public static int[] fill(int[] arr, int k, int n){         int[] arr2 = new int[n];         int cnt = 0;         if (k > 0 && n > 0)         {             while (cnt != n)             {                  for (int j = 0; j < k; j++)                 {                     if (cnt != n)                     {                         arr2[cnt] = arr[j];                         cnt++;                     }                     else                         break;                 }             }         }         else             return null;          return arr2;     }


How do I download and not pay another 16 bucks?

I downloaded Ubuntu 13.04 (64 b) and donated my 16 bucks, and I cannot find it on my computer anywhere.


How to create LEGO mountainous landscape?

I wanted to create a LEGO landscape based on the LEGO Movie's way of doing it. I've tried turning a LEGO fluid simulation from a tutorial into a stagnant landscape, without any results. Here is an example picture of a desert scene from The LEGO Movie:   Thanks for any help!


I write some code like this:   public static void function7() {     String str = "123";     String str2 = "123";     synchronized (str) {         if(str != null) {             str2 = "123";         }else{             str = "456";         }         System.out.println(str2);     } }   The code compile well. But a plugin of Eclipse, Find bugs, give the follow error report:     Constant Strings are interned and shared across all other classes loaded by the JVM. Thus, this could is locking on something that other code might also be locking. This could result in very strange and hard to diagnose blocking and deadlock behavior.    What exactly it means?


How should I prove that $c^n/n!$, where c is a constant, tends to zero for a large n.

I want to prove that $$\frac{c^n}{n!}$$ tends to zero when $n$, a positive integer, is quite large. I do not think I can use L'Hospital's rule here as $n$ is discrete. Should we assume $n$ to be continuous to sove this problem. Furthermore, I do not find approximating $n!$ with gamma function of much help.


How to fix this java.lang.nullpointerException using selenium

I am getting exception      Exception in thread "main" java.lang.NullPointerException    at com.wd.programs.Gmail_Login.email(Gmail_Login.java:17)    at com.wd.programs.Gmail_Login.main(Gmail_Login.java:29)   while running the following code.   public class Gmail_Login extends HandlingDropdowns  {     WebDriver driver ;      public Gmail_Login (WebDriver d) {       super(d);     }      public void email(String e) {        driver.findElement(By.cssSelector("input[type='email']")).sendKeys(e);     }        public static void main(String[] args) {       WebDriver driver = new FirefoxDriver();       Gmail_Login gl = new Gmail_Login(driver);       gl.openApplication("http://www.gmail.com");       gl.email("rize.test1");      }   }


How can i prove that $ \forall x \in \mathbb{R} \displaystyle \lim_{n \to \infty} \dfrac{\left \lfloor{x}\right \rfloor+\left \lfloor{2x}\right \rfloor+\cdots+\left \lfloor{nx}\right \rfloor}{n^2} = \dfrac{x}{2} $?  I tried $A_{n}=\dfrac{\left \lfloor{x}\right \rfloor+2\left \lfloor {x}\right \rfloor+\cdots+n \left \lfloor{x}\right \rfloor}{n^2}$,  $B_{n}= \dfrac{\left \lfloor{x}\right \rfloor+\left \lfloor{2x}\right \rfloor+\cdots+\left \lfloor{nx}\right \rfloor}{n^2}$,  $C_{n}= \dfrac{x+2x+\cdots +nx}{n^2}$  So $A_{n} \leq B_{n} \leq C_{n}$  $ \Rightarrow \displaystyle \lim_{n \to \infty}A_{n} \leq \displaystyle \lim_{n \to \infty} B_{n} \leq \displaystyle \lim_{n \to \infty} C_{n} \iff \dfrac{\left \lfloor{x}\right \rfloor}{2} \leq \displaystyle \lim_{n \to \infty} B_{n} \leq \dfrac{x}{2}$  But I dont know if thats all or Im missing something


What zone is a spell or ability in when it is resolving?

When I cast a spell or activate an ability, or a triggered ability triggers, it goes on the stack, and then some time later, it resolves. Is it still on the stack while it is resolving? If not, is it some other zone or somewhere else entirely? If it's a spell, when does it go to the graveyard?


Is there a word for percentages, like "median" is for 50%?

Wikipedia article  says:     In statistics and probability theory, the median is the value separating the higher half from the lower half of a data sample, a population or a probability distribution.   Which can be rephrased as:     In statistics and probability theory, the median is the value separating the higher 50% from the lower 50% of a data sample, a population or a probability distribution.   Is there a term for: "a value separating the higher (100−N)% from the lower N% of a data sample, a population or a probability distribution" ?  Edit:  The question  itself answers my question because it happens to contain the word I was looking for. But technically it is not a duplicate.