How do I identify a railway station’s official WiFi

While I was waiting in the Nottingham railway station I wanted to connect to the WiFi. However, I found 4 unsecured WiFi networks:   TheCloud _Notts City Free WiFi NET WiFi NCTX WiFi   I had no idea which one was official, and which might be fake ones provided by people intent on stealing my browsing habits.  Is there any way to determine the official WiFi? Would railway staff members know? Is there a list of WiFi networks in UK railway stations somewhere?  An answer that is applicable to railway stations in general would be great - I go through a lot and asking a question here for 8 different stations seems a bit silly.  Finally - I know public WiFi is deemed untrusted, so I use a VPN which I do trust and browse with Safari, rather than the official Apps, so that I can see the green padlock indicating HTTPS.


Showing that $\lfloor\frac{x-1}3\rfloor=\lfloor\frac{x}3+\frac23\rfloor-1$ and $\lfloor\frac{x+1}3\rfloor=\lfloor\frac{x}3+\frac13\rfloor$.

I have 2 questions about the floor functions:  1) $\left\lfloor \frac{x-1}{3}\right\rfloor =\left\lfloor \frac{x}{3}+\frac{2}{3}\right\rfloor -1$  2) $\left\lfloor \frac{x+1}{3}\right\rfloor =\left\lfloor \frac{x}{3}+\frac{1}{3}\right\rfloor$  As we know that the definitions and properties of floor functions are:  1) $\lfloor x\rfloor =m$ if $m\leq x<m+1$ and  2) $\lfloor m+x\rfloor =\lfloor x\rfloor +m$ if $m$ is an integer.  Questions:  1) Why the first floor function above has to +1 inside the floor brackets and -1 outside the floor brackets:    $\left\lfloor \frac{x-1}{3}\right\rfloor$ = $\left\lfloor \frac{x-1}{3}+1\right\rfloor -1$ = $\left\lfloor \frac{x}{3}+\frac{2}{3}\right\rfloor -1$  2)Why the second floor function above doesn't need to add or minus 1 inside or outside the floor brackets:   $\left\lfloor \frac{x+1}{3}\right\rfloor$ = $\left\lfloor \frac{x}{3}+\frac{1}{3}\right\rfloor$  Does anyone here know the reason? Thank you.


Apex - Accurately Identify users tagged in Chatter comments and set them as followers automatically

I already know how to set someone to auto-follow a record based on specific criteria (record created, modified, etc) by inserting records into the EntitySubscription object.  What I am trying to accomplish is a process in which, for a specific internal object, anyone who is @Mentioned on a chatter text post that is related to that object type will automatically become a follower of the record that they were mentioned in.  I can query for the information I need from the FeedItem object with [SELECT Id,ParentId,Body FROM FeedItem WHERE Type = 'TextPost'], but the body looks like this:     @Person One @Peron Two @Person Number Three can one of you provide me with a specific account that you are referring to?     Issue: I don't use regex often, but figured it would be useful here, however my problem is that there isn't really any clear 'line in the sand' in the Body of the FeedItem for me to tell the regex when to start/stop and guarantee that I've captured the full name of the user, and without the full name of the user I can't properly query for their User Id and insert their EntitySubscription record(s).  In my example above you'll note that I can't just rely on the two words that immediately follow an @ symbol, because there are some users who have a multi part name (Morgan Del Ray, as an example). I was hoping that the @Mentions would be formatted as @[Mention] so that I could use the [ ] as my limiters, but alas it is not.    Question: Is there any way I can guarantee this functionality will capture the full name using an advanced form of regex? Or is there perhaps another object that actually stores the Id references of the users that were tagged in a post? Somehow Salesforce manages to turn the @Mention tag into a link to the User, but I don't see that in the FeedItem object so I'm not sure where (or if) I can reference that data directly.


How to Call two action from one Command Link?

I have to call 2 URL on click of command Link , one will Record Edit Page URl and Another is different Webserver URl  I have tried two Ways Both are Not Working.....I mean both action is Not Performing  OPTION 1  <apex:column >    <apex:commandLink value="Click" action="{!meth1}" target="_blank" onclick="methodInJavascript();">          <apex:param value="{!ll.Mobile__c}" assignTo="{!toMObile}" name="assignvalue" />    </apex:commandlink> </apex:column>    <apex:actionFunction action="{!meth2}" name="methodInJavascript" />   Apex Class  public PageReference meth2() {     Pagereference p2 = new  Pagereference('https://ap2.salesforce.com/a0A28000000okkjEAA/e'); p2.setredirect(true);  return p2;     }       public PageReference meth1() {     Pagereference p1 = new Pagereference('https://www.google.com'); p1.setredirect(true);  return p1;     }   Here Only  Meth1() is Executing  OPTION 2  <apex:column >    <apex:commandLink value="Click" action="{!meth1}" target="_blank" onclick="window.open('https://ap2.salesforce.com/a0A28000000okkjEAA/e')">          <apex:param value="{!ll.Mobile__c}" assignTo="{!toMObile}" name="assignvalue" />    </apex:commandlink> </apex:column>   Pagereference URL will be dynamic....I will be Passing parameters  ' ' + a.id + '/e';


If a question receives n (say, 5) rollbacks within a hour, raise a moderator flag and lock the post.  Alternatively, if an edit by a new user (say, no edit approving privs) drops the post quality score of a post "too much" (say, by more than 100), it must go through the edit approval process.


ASP.Net MVC2 web app capable of plugins and themes architecture

I am wondering if ASP.Net MVC 2 is a good choice for my current project. I want to build a social site that will allow for plugins or modular apps to be added on to it. An example of what I am talking about would be socialengine.net or even Joomla.  I was thinking that mvc areas would make good modular apps to plug into a core app but wondering if some sort of installer could be created that would wire things up automatically.  Anyone know of any examples of this somewhere on the net?


Please help prove that $(x_n)$ is a Cauchy sequence if $|x_{n+1} - x_n| \leq Cr^n$

Past final exam question for an intro to Real Analysis course:  Let $C > 0$, $0<r<1$ and suppose that $\forall n\in \mathbb N, |x_{n+1} - x_n| \leq Cr^n$. Please help me prove that $(x_n)$ is a Cauchy sequence. (We can assume the $\lim\limits_{n\to\infty} r^n=0,$ for $0<r<1$)  So, I know that a Cauchy series must satisfy $|x_{n}-x_m| < \epsilon$ for any $\epsilon>0, \in \mathbb R$ and for all $n,m \gt H(\epsilon) \in \mathbb N$ Note that there can't be any conditions on n and m (I saw somewhere else someone required $m>n$ which you can only do if you're proving its not at Cauchy sequence, right?)  Another way of doing this is showing that it is contractive (and thus a Cauchy series) if there is a constant $a$ such that $|x_{n+1}-x_n| \leq a|x_n-x_{n-1}|$   Clearly I'm supposed to make use of $\lim\limits_{n\to\infty} r^n=0,$ for $0<r<1$... But I don't even know how where to start with this. As I am bumbling through this problem, a more thorough answer would be much appreciated. Thanks!


What is wrong with my matrix multiplication code?

I need to multiply any two matrices (that have correct dimensions allowing it) in Python3 without using any imports except for math. (So no numpy).  That said, here is what I came up with:  def dotMatrix(m1, m2):     m1rows = len(m1[0])     m1cols = len(m1)     m2rows = len(m1[0])     m2cols = len(m2)     newcolumn = [0]*m2cols     m = [newcolumn]*m2rows     sum = 0      for a in range(m1rows):         for b in range(m2rows):             for c in range(m2cols):                 sum += m1[a][c]*m2[c][b]              m[a][b] = sum             sum = 0      return m   a = [[1,4],[2,5],[3,6]] b = [[7,9,11],[8,10,12]]  c = dotMatrix(a,b) print(c)   It is supposed to return [[58,139],[64,154]], but instead it returns [[54, 68], [54, 68]]. Why is this?  I am working off of the example on


How do you make binomial pricing trees using tikz? I mean a tree like the this, but with only three time periods.


I read on the wiki that people will move in under the following conditions:   You do something to please them An empty house is available with a light source, table, and chair (also with walls).   I have a house which is about 7x8, then a roof space above that; about half the area. I could put furniture up there too, but will anyone move in?


Could there be a bit of reputation leakage between the sites, please?

It's a bit frustrating that, even though I'm above rep 100 on Stack Overflow, I'm still restricted with the most basic 'idiot prevention' limits on the other sites as I start there. Really, is it necessary to prevent me from creating a new tag or posting more than once in 20 minutes? I can see holding off edits, or even comments, until I've proved to have a brain in the domain in question.  You could see this as a request for a feature.


I'm playing xbox one and my villagers are not breeding. I am pretty sure I saw green sparkles over their heads and idk what that means, but I haven’t seen red hearts over their heads. I have a structure made with a ton of beds. Also, doors above the ceiling and those doors are smooshed together by another layer of blocks on top. There is a ton of light, but no red hearts. I’ve been waiting for about 20 minutes.


What is the difference between  [Flags]     public enum AnswerFlags     {     A = (1 << 2),     B = (1 << 1),     C = (1 << 0)     }   and     public enum AnswerFlags         {         A = 4,         B = 2,         C = 1         }   And why should i work with bits instead of integers?


I am trying to use graphicx package to include figures. However it seems to leave  too much space between the figure and caption.  My LaTeX lines are   \begin{center} \includegraphics[scale=0.6]{1hamlabels.eps} \end{center}   Is there any way to reduce this space while using graphicx package? I dont wanna use tikz or anythin like that.  Thanks


Why is Dictionary preferred over Hashtable in C#?

In most programming languages, dictionaries are preferred over hashtables. What are the reasons behind that?


How can I find saved WiFi passwords within non-rooted phone?

I have Android phone which is non-rooted. How can I know the saved WiFi passwords in my phone?


What is the UMVUE of $\exp(-2\lambda)$ for X is a random variable with poisson distribution~poisson $(\lambda)$

If $X_1,X_2,…,X_n\sim Pois(λ)$, find the UMVUE of $\exp(−2λ)$. I know based on lehmann scheffe theorem, the step is  (1)find $q(x)$ an unbiased estimater of $\exp(−2λ)$  (2) $T(X)$ is sufficient and complete  (3) $s(*)=\mathbb E(q(x)|t(x))$ is a UMVUE  (4) var$(s(*))$ <$\infty$, then it is the UMVUE  The answer IS: y=(-1)^x, when x is even y=1,when x is odd, y=-1.  But I still do not know step by step, how to make it work?


Execute vs Read bit. How do directory permissions in Linux work?

In my CMS, I noticed that directories need the executable bit (+x) set for the user to open them. Why is the execute permission required to read a directory, and how do directory permissions in Linux work?


Is it possible to connect a Android phone display to a TV or PC Monitor?

Is it possible to make the display on a Android phone to a TV or a PC Monitor?   What are the methods that I can connect the Android phone to a TV (e.g. plasma TV) or a PC Monitor and then modify some configuration in the phone so that the display will be shown in the TV or the PC Monitor screen?


$ su - Password:  # echo $PATH /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin # exit logout $ su Password:  # echo $PATH /usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games   I have no idea why /bin and /sbin are not added to $PATH, if I do the plain su. This used to be the case. How can I fix this? I did notice that:  -rw-r--r-- 1 root root 0 Jan  8  2018 /etc/environment   But otherwise my system seems normal.  EDIT: I forgot the obligatory uname -a  Linux rpi3 4.17.0-1-arm64 #1 SMP Debian 4.17.8-1 (2018-07-20) aarch64 GNU/Linux   EDIT2:  $ cat /etc/issue Debian GNU/Linux buster/sid \n \l   all of the packages are from the "testing" repo, since "stable" ones don't work very well on aarch64.


Example of function that cannot be expressed as a power series

I want to find an example of a $\textbf{continuous everywhere}$ function but can't be expressed as a convergent power series $\sum_{n=0}^{\infty}c_n(x-a)^n$ near a point $a$ (i.e. on $(a−\epsilon,a+\epsilon)$ for all $\epsilon$, a is constant).  Do I need to consider some Fourier series?


Clipboard setData ( html ) in javascript

Is there a way to set the data of the clipboard as html instead of plain text ? I know this is easely done in C# with :  Clipboard.SetData(DataFormats.Rtf, (Object)temp);   But i'm looking for a javascript solution ( can include jquery etc ... )  Edit: this only needs to work for Internet Explorer


Calculating Statistics Based on Expression in QGIS?

Is it possible to calculate the sum of polygon areas based on whether or not it has a value in another column?   For example:  In column 2 I have the area of polygons. I want to calculate the area of all polygons that contain 'AG' in column 1 or all polygons that are IN column 1. But calculate them separately so I can get the total area of each type in column 1.


Slow performance clipping raster with GDAL

I have a few large LiDAR DEMs that I want to merge. Each DEM has some glitches around the borders which need to be removed in order to get a seamless final product. I manually traced around each DEM to create a polygon which excludes the glitchy areas. I am using gdalwarp to clip the raster files, but I am experiencing very slow performance.  The rasters are between 3 and 10 GB, which I understand is pretty big… however I have ~3 ghz of processing power & 4GB of RAM. These rasters load into QGIS quickly and are quick to refresh. I can derive a hillshade or slope raster from one of these DEMS in 2 or 3 minutes.. so it seems unreasonable when it takes 4-6 HOURS to clip one of these rasters with gdalwarp.  Can anybody offer an explanation of what might be going on?  I am also bothered by the very large file sizes (up to 4x larger than the original) which result from the clipping. Research suggests that this is a compression issue, but gdalinfo does not return any compression info for any of the original rasters, and even when I compress the files are still 2x larger than the originals. Could there be any reason for this other than compression?


How to make an align environment with multiple equations per line and one equation reference?

I would like to use an align environment with a single equation number but with multiple equations per line. For example, the following two pieces of code work:  begin{align} a&= 1 & b&= 2 + 3\\ c&= 4 + 5 & d&= 6\ \end{align}  begin{align}\begin{split} a&= 1\\ c&= 4 + 5 \end{split}\end{align}   The second example succeeds in having one equation reference in the middle, and the first succeeds in having multiple equations per line. How might I have multiple equations per line with one equation reference? Thanks!


How to prove zeros of a real analytic function (non-zero function) is always countable?


Why does front wheel keep more air pressure then rear wheel over time?

After pumping both the tires equally, after a  few weeks pass, the rear tire of my bicycle keeps on getting flatter day by day, and looses pressure. I have checked everything and there is no leakage anywhere.  Why always does it effect rear wheel?


My tittle on SERP do not exact match with my tittle tag

Can anyone here help me about my title problem in google?  My title in google result page do not exact match with my title tag. If you search with keyword "itclax furidacchi" in google, my title there is a anime word. Im not use anime word in my title. I dont know what must i do again, i inspect element doesnt work, nothing anime word in my element site.!    NB: one of author make my question is duplicated, but i cannont resolve my problem with read duplicate post.


What does the DC in Orcus' voice lair action refer to in Mordenkainen's Tome of Foes?

Orcus, the demon lord of undeath, is listed in Mordenkainen's Tome of Foes on page 152-153. He has several lair actions, including the following:     Orcus's voice booms throughout the lair. His utterance causes one creature of his choice to be subjected to power word kill (save DC 23). Orcus needn't see the creature, but he must be aware that the individual is in the lair.   Power Word Kill, however, states:     You utter a word of power that can compel one creature you can see within range to die instantly. If the creature you chose has 100 hit points or fewer, it dies. Otherwise, the spell has no effect.   There is no save DC, that's the whole point of the spell (which is 9th level).  Why is there a save DC given for Orcus' lair action? Is it for balancing purposes, so that players don't have to deal with a "you most likely die now" feature every round? Or could it be a mistake from the developers? It would clearly be too strong without a save, but even with that, a DC of 23 makes success unlikely if you're not proficient and naturally good with the relevant save ability (which is not given and therefore unknown).  I'm specifically interested if there are other features with similar issues, and if there are any rulings/statements from official sources about it*.    Of course, if the given DC is not a mistake, but rather intentional, it raises the question which ability to use for the saving throw. CON would make sense, but RAW, none is given.    * I'm aware that developer intent is considered off-topic for some time now. Feel free to answer this question without designer quotes, though I don't see how this issue could be resolved without insight from a designer. Still, maybe you'll discover something I missed :)


how can i setting utf-8 from csv file to phpmyadmin

I got some problems that my result not right (i think it's not UTF-8).  This is input(CSV file)    This is output (in phpmyadmin)    Please Help!   $file_data = $this->upload->data();         $file_path =  'upload/file_csv/'.$file_data['file_name'];         if ($this->csvimport->get_array($file_path)) {             $csv_array = $this->csvimport->get_array($file_path);                  foreach ($csv_array as $row) {                     $insert_data = array(                                                    'firstname'=>$row['tea_name'],                         'lastname'=>$row['tea_surename'],                         'teacher_id'=>$row['teacher_id'],                     );                         $tea_id = $insert_data['teacher_id'];                         $fname = $insert_data['firstname'];                         $lname = $insert_data['lastname'];                          for($i=0;$i<sizeof($insert_data);$i++){                             $sql = "select * from teacher where teacher_id = '$tea_id' ";                                                        $result = $this->db->query($sql)->num_rows();                         }                          if($result>0){                                                           $sql="UPDATE `dvp`.`teacher` SET `firstname` = '$fname', `lastname` = '$lname' WHERE `teacher`.`teacher_id` = '$tea_id'";                             $this->db->query($sql);                         }else{                             $sql="INSERT INTO `dvp`.`teacher` (`teacher_id`, `firstname`, `lastname`) VALUES ('$tea_id', '$fname', '$lname')";                             $this->db->query($sql);                         }                   }


what do you call a person who does not like to share information?

Is there any word for a person who does not like to share information?


How I can use the POST method to pass a array of files?

I have an array of files that you receive files of an input type = file. I can not use the input because the user must have the ability to cancel a file. I need to pass this file array to my webservice in Java using ajax. How I spend my array using the method POST without using the form?  My big problem is the token and the header, the two need be dynamic and I deal in form, but in this case, I do not a form, I want to spend a var filearray declared in JavaScript. I cannot use a jQuery library file upload, because I need to show the files in other div after an user cancel a file and I have no idea how I show the files in other div because the library clean the input after the user chooses the files. I do not know where the library puts the files for me to handle them. "var filearray = []" is a global variable.  My HTML:  <input type="file" id="myFiles" multiple size="50" onchange="myFilesFunction()">   My JS:  function myFilesFunction(){ var x = document.getElementById("myFiles"); var contfilearray = 0; for (var i = 0; i < x.files.length; i++) {     filearray[contfilearray] = x.files[i];     contfilearray ++; }}   My Ajax:  function salvaanexoszip() { var numeroticket = 12345; var data = new FormData(); jQuery.each(jQuery(filearray)[0], function(i, file) {     data.append('file-'+i, file); });   $.ajax({     url: 'URL',     type: 'POST',     cache: false,     contentType: false,     processData: false,     data: {         ticket: numeroticket,         files: data,     },     success: function(data) {         alert("OK");     },     error: function (xhr, ajaxOptions, thrownError) {         alert("NOT OK");     } });}


How can I tell whether "c" should be pronounced like "s" or like "k"?

How can I tell whether "c" should be pronounced "s" or "k"? I always get confused and pronounce it like "s" because it looks like russian "с".


In the $XY-$ plane consider the family $\mathcal{P}$ of inverted parabolas that pass through the origin such that the tangent vector at the origin has equal norm (say $\lambda>0$) for all of them. One of such representation can be $$\mathcal{P}=\{p(t)=(x(t),y(t)):x(t)=\lambda\cos(\alpha)t,y(t)=\lambda\sin(\alpha)t-at^2,\alpha\in[0,\pi],a>0\}$$ Find the curve that is tangent to all of the parabolas in $\mathcal{P}$.


How a callback function can modify an object member?

To illustrate the question, let's imagine a dummy example where we have this function from an external API:  // This function is run in a separated thread void Transfert(string source, string destination, void (*callbackFunction)(int)) {     for(int i = 0; i < 100; i++)     {         // Simulation of a file transfert         // ...         //           // We call the callback function to update the progression of the file transfert         callbackFunction(i);     } }   I want to use this function to transfert a file and follow the progress with the help of the callback function. Here is my code:  // Class containing information about the transfert class FileTransfert { public:     FileTransfert(string, string);     void MyCallback(int);      // Those members are public to simplify this example but should be private     long m_progress;     string m_source;     string m_destination; };  FileTransfert::FileTransfert(string source, string destination) {     m_source = source;     m_destination = destination; }  // Used to update the progress variable void FileTransfert::MyCallback(int progress) {     m_progress = progress; }  int main(int argc, char* argv[]) {     FileTransfert f("source.txt", "destination.txt");      // It's a new thread     Transfert(f.m_source, f.m_destination, f.MyCallback); // Compilation error      // Now I want to follow the transfer with the m_progress variable      return 0; }   My class FileTransfert has a m_progress member and I would like to refresh it during the file transfert. So I create a callback function who updates m_progress. The problem is I cannot use a method of an object as a callback function.  So, here is my question : how can I modify my code to follow the progression of the transfert?I have some constraints : I have to call Transfert from a function who is outside the FileTransfert class and the m_progress variable has to be inside the FileTransfert class. In other words, I can't change all the architecture of my code.  Important note: I can't change the code and the signature of the Transfert function. In the answers of those two questions ( and ), we change the signature of the function but I can't in my case.    EDIT  As I said in comments, there is no proper solution to this problem if I can't change the signature of the Transfert function. One idea is to use global variables but it can be very risky in a multithread environment.


How to add text and figures one by after severals time?

When I try to add 2 figures and to add text between them, after compiling the text, I get the results: texts above and the two figures below...  I expected to have first figure and text after and after the text another figure and after the last figure another text.  Why it separate them in shape of two text and after the text two figures ?  first part:  The output results that shown in \autoref*{capacitors_voltages} help us to bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb \begin{figure}[!h]     \centering     \includegraphics[width=0.9 \textwidth]{figures/CAP_voltgs}     \caption{capacitor waveforms.}     \label{capacitors_voltages} \end{figure}   From \autoref*{ACcurrents} we can see aaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa \begin{figure}[!h]     \centering     \includegraphics[width=0.9 \textwidth]{figures/currents}     \caption{AC side currents}     \label{ACcurrents} \end{figure}   second part:  So, in this code part it behave exactly as I expected:  The number of SMs usually depends on the application,it is very common of using letter N to indicate the number of SMs in each ARM and 2N to whole phase.   \begin{figure}[!h]     \centering     \includegraphics[width=0.9\textwidth]{figures/Three_MMC_Phase2}     \caption{General one and three phase of modular multilevel converter (a) and (b) respectively}     \label{figures/Three_MMC_Phase2} \end{figure}   The fundamental construction of SM composed from capacitor, IGBTs (S1,S2) and their corresponding free-wheel diodes.\\  The two most common SM configurations found in literature are the Half-Bridge (HB) and Full-Bridge (FB) SM, as illustrated in \autoref*{figures/HB_FB}.  The FB-SM version of the MMC has twice as much semiconductor devices than the HB version, which results in higher losses, but confers certain advantages as well \cite{6864817}, \cite{6631955}.   \begin{figure}[!h]     \centering     \includegraphics[width=0.9\textwidth]{figures/HB_FB}     \caption{Converter configuration submodules: (a) half-bridge and (b) full-bridge}     \label{figures/HB_FB} \end{figure}   For the present analysis, and throughout the Thesis in general, the MMC under study is considered to be based on HB-SMs. Considering submodule structure , is a simple half bridge with a capacitor bank, as shown in \autoref*{figures/HB_FB}. Each phase leg of the converter has 2 ARMs, each one constituted by a number of series connected submodules.  So what wrong with the first part ?


Why can't I comment back when my question has been commented by others?

After asking a question in  using a guest account, I have signed up using the verification link in my mailbox. But now logging into the same mail, I cannot comment back on a comment asked by other members regarding the question asked previously. I want to let others understand the situation.


Can a class overload methods that also exist in the publicly inherited interface? It seems like this is unambiguous and useful, but compilers (VC, Intel, GCC) all complain, at least by my construction. Below is a toy example. The inherited rebound() function has two clear overloads, yet this will not compile.  If you rename the rebound() method in either class, it works fine, but if they share the same member function name (even though they're overloaded with different argument types!) you get a fatal error of "too few arguments to function call."  The workaround is trivial (I'll just rename the methods) but I'm just trying to understand if this is a C++ restriction (and why it would be).   #include  class Bound { public:   Bound() : x0(0.0), x1(0.0) {};   Bound(double x) : x0(x), x1(x) {};   double width() const {return x1-x0;}   void rebound(const Bound *a, const Bound *b); private:   double x0, x1; };  void Bound::rebound(const Bound *a, const Bound *b) {   if (a && b) {     x0=std::min(a->x0, b->x0);     x1=std::max(a->x1, b->x1);   } }  class Node : public Bound { public:   Node(double x) : Bound(x), left(0), right(0) {};   Node(Node *a, Node *b) : left(a), right(b) {rebound();}   void rebound() { rebound(left, right); } private:   Node *left;   Node *right; };   int main() {   Node A(1.0);   Node B(2.0);   Node C(&A, &B); }


Creating a single index from several principal components or factors retained from PCA/FA

I am using Principal Component Analysis (PCA) to create an index required for my research. My question is how I should create a single index by using the retained principal components calculated through PCA.  For instance, I decided to retain 3 principal components after using PCA and I computed scores for these 3 principal components. What is the appropriate ways to create, for each respondent, a single index out of these 3 scores?   Is it relevant to add the 3 computed scores to have a composite value? Or to average the 3 scores to have such a value?  Or should I just keep the first principal component (the strongest) only and use its score as the index?   Alternatively, one could use Factor Analysis (FA) but the same question remains: how to create a single index based on several factor scores?


Does a zero-damage attack still count as a hit?

Does an attack roll that 'hits' according to an the attack roll, but deals zero damage (perhaps through damage reduction or through poor rolls and resistances, as in ) still count as a hit for the purposes of things like  or ?  Does it count if the target is immune?  I found a similar question -  - but that's for Pathfinder rather than 5e.


Let's encourage the commenter with the correct answer to post it as an answer

It's been a while in Stack Overflow, and I have seen so many times that an actual answer was provided as a comment to the question. Later, I see a list of answers repeating the same thing.  Yes, I know, usually the comment is voted up, however, the poster who actually commented with the perfect answer, ethically waits for OP's reply. And then, what we see is a series of answers on the basis of the previous comments.  The poster providing the correct answer through comment, should be encouraged to post it as an answer when majority of us think so.


How to get the full executable name of a running process in Linux

I'm writing a script which will use the filename of running processes. However, I'm unable to determine the full executable name of some processes.  Initially, I decided to query the Name entry in /proc/PID/status (or the second field in /proc/PID/stat). However, according to the , that field is always truncated to 15 characters, but I need the full name to avoid conflict/confusion.  An answer of  suggests to use /proc/PID/cmdline, but there are problems too. Some programs (e.g. chromium, electron) do stupid/smart things to the value in /proc/PID/cmdline so I can't just split the data there by NULL and directly get the program name as suggested in the manpage - they fill in a lot of things to the original argv[0] field and separate them by space, and I don't think merely splitting by space is a good choice because the path/filename may contain spaces.  This is even more complicated when I find out that some scripts (e.g. python scripts) are in the form /usr/bin/python /path/to/script while some are in the form /path/to/script. Though this is much easier to deal with as long as I have that field (without jams as above) and manually check and split.  Any ideas how to get the full program name/filename? It doesn't matter if the name contains the full path or not because that can be easily dealt with (as far as I can see now).


Strange sentence structure from a piece by Paula Gunn Allen

This lesson is in a pattern book. I want to know why the word about is repeated quite a few times in the text:      My mother told me stories about cooking and childbearing; she told me   stories about menstruation and pregnancy; she told me stories about   gods and heroes, about fairies and elves, about goddesses and spirits;   she told me stories about the land and the sky, about cats and dogs,   about...


I have a doubt regarding id() in python.  >>> x=2 >>> y=2 >>> id(x) 94407182328128 >>> id(y) 94407182328128   But if i do the same to list,i get different id's   >>> a=[1,2,3] >>> b=[1,2,3] >>> id(a) 139700617222048 >>> id(b) 139700617135528   WHY is it so? why for int type i get the id's same and why different for lists?  Thanks in Advance.


Suppose G is a group of order 4 and $x^2=e$ for all $x$ in G. Prove that G is isomorphic to $Z_2\oplus Z_2$.

Suppose $G$ is a group of order $4$ and $x^2=e$ for all $x$ in $G$. Prove that $G$ is isomorphic to $Z_2\oplus Z_2$.  My attempt:  (1) Show that $G$ is abelian.  \begin{align*} \text{Take }x,y\in G.&\text{Then }xy\in G.\\ (xy)^2&=e\\ \text{Thus } (xy)^{-1}&=xy\\ \text{Also by socks-shoe property }(xy)^{-1}&=y^{-1}x^{-1}=yx\\\\\text{Thus we have }&xy=yx \text{ and $G$ is abelian}. \end{align*}  (2) Show that $Z_2\oplus Z_2$ is abelian. $$\text{This can be easily verified.}$$ (3) Define the isomorphism $\phi$  $$\text{Let $G$}=\{e,a,b,c\}\\ \text{Define } \phi \text{ from $G$ to $Z_2\oplus Z_2$ such that}\\ \phi(e)=(0,0)\\\phi(a)=(0,1)\\\phi(b)=(1,0)\\\phi(c)=(1,1)$$ $$\text{Clearly $\phi$ is one-one and onto.}$$How do I show that $\phi$ is operation preserving?If this is not the right way the proof is going, please post the solutions.


Blog posts use the wrong icon in the feed on the mobile apps (both Android and iOS)

Today in the feed on the Android Stack Exchange app there is a Stack Overflow blog post. This post had the site icon next to it for  rather than the proper site logo (Meta).        Stack Exchange Android App Version 1.0.73 and 1.0.74 Android 5.1 on a Moto X (2013) running stock firmware.  Same behavior on a Nexus 7 (flo) running Android 6.0 (stock).  This issue also happens on the iOS app.    The most recent featured SO blog post (as of 17 Nov) is showing up with the "edX" site logo.  The logo is seemingly randomly incorrect.


What does Lucius Malfoy do for work? I know they have a lot of gold, so how did the family obtain it? Was it inherited just like the Potter family? He was a school governor, but was that his only job? Not sure if school governors actually get paid. I don't think he actually worked at the ministry, from what it says in the novels he just stopped in from time to time to give good to various organizations.   Harry Potter Order of the Phoenix  Chapter Educational Decreee Number 24 quoting Draco Malfoy     'Yeah, Umbridge gave the Slytherin Quidditch team permission to continue playing straightaway, I went to ask her first thing this morning. Well, it was pretty much automatic, I mean, she knows my father really well, he's always popping in and out of the Ministry . . . it'll be interesting to see whether Gryffindor are allowed to keep playing, won't it?'   Does anyone know what Lucius Mafoy's job was and how be has so much money?


Induction - request for help in proving lemma

Could anyone help with proving the following lemma, please?  Let: $n\in \mathbb{N}$, $Z_{n}^{*}:=\{k\in\mathbb{N}: k\in\{1,\dots,n\}  \wedge \space   GCD(k,n)=1\}$. Then: $\forall n\in \mathbb{N} \space \forall  p \in \mathbb{P}: |Z_{p^{n}}^{*}|=p^{n}-p^{n-1}$  I tried to prove this by induction with respect to $n$, but I stuck at general case. I know how induction works, but I can't see how to do main point...


Can’t you just knock a prophecy off the shelves and smash it to hear what it says in the Department of Mysteries?

In Harry Potter and the Order of the Phoenix, there’s a point in the Department of Mysteries where two prophecies get smashed and are able to be heard. But these two prophecies are not about anybody present. Couldn’t one of the Death Eaters do this for the prophecy about Harry and Voldemort? Just smash the prophecy off the shelf and listen to it?


How to bake a blender shader into a colored image mapped to the UV of a model

Me and my friend have this metal texture created in blender with nodes for a robot model. How would we take this shader and turn it into basic uv image texture with colors for the model in unity? Thanks in advance!


What does this line mean in /etc/crontab file ?  59  *  * * *    root    rm -f /var/spool/cron/lastrun/cron.hourly


looking for a screen recorder for ubuntu 16.04

looking for a screen recorder for 16.04 that can record my screen be able to pause and resume record ingame audio and audio from other things like discord for when im playing with my friends does anyone have any ideas.


Isn't that the place which kids under twelve can't enter?

Should "where" be used instead of "which"? The sentence should be:     "Isn't that the place where kids under twelve can't enter?"   as "where" is the object pronoun to replace "the place" (where to enter). Using "which" is totally wrong as it is replacing the object for place.


How to find and delete duplicate files within the same directory?

I want to find duplicate files, within a directory, and then delete all but one, to reclaim space. How do I achieve this using a shell script?  For example:  pwd folder   Files in it are:  log.bkp log extract.bkp extract   I need to compare log.bkp with all the other files and if a duplicate file is found (by it's content), I need to delete it. Similarly, file 'log' has to be checked with all other files, that follow, and so on.  So far, I have  written this, But it's not giving desired result.  #!/usr/bin/env ksh count=`ls -ltrh /folder | grep '^-'|wc -l` for i in `/folder/*` do    for (( j=i+1; j<=count; j++ ))    do       echo "Current two files are $i and $j"       sdiff -s $i  $j       if [ `echo $?` -eq  0 ]       then          echo "Contents of $i and $j are same"        fi     done  done


Why are new sites classified as "uncategorized"?

I can imagine that it is a little bit hard if you're not a native Japanese or Russian speaker to figure out where those new sites are and what they are about. Putting them under uncategorized is not what those new sites deserve.              I understand from previous incidents  that  end up in this category for a while.    Can we make sure that new sites get properly categorized?


Feed not updating after clicking notification

Hey, this is pretty much the first time I'm using the app.   I got a notification for a question I asked. It opened the app and the feed drawer, but it did not pull the actual notification. I was able to swipe down to refresh and then it showed up.


How can I use the Android Paid Market from a region where it's not available yet?

I live in scandinavia and the Market for paid applications is not available here yet. Is there any way I can enable it? Or a workaround?


A single word for "non-empty" or "not empty"

Much like the poster who posted this:    I'm simply looking for a single ("short" if possible) word that means "non-empty" or "not empty".  I'm not looking for the word "full".  For example, a cup can be empty, or it can contain some liquid, in which case you could describe it using the word I'm searching for.  None of the answers or comments in the above post really fit what I'm looking for.


Fix files seen as removed instead of renamed in pushed commit

I know that, when moving a file, you need to git add the "new" file and git rm the "old" file so git can see it as renamed rather than removed... but how can you fix a (pushed) commit that didn't do this properly?  I made a commit directly in Visual Studio and I wasn't paying enough attention - it renamed multiple files, and they now show as if the old files were removed and new ones were added, rather than the old files being renamed. I only realised this after having pushed multiple commits on top. Is there a way to fix it?  (And bonus question - why didn't Visual Studio handle this properly and how could I make it work next time, without having to use separate terminal commands?)


JavaScript: Why are local variables usable after the execution of their containing context?

function Person(name) {      Object.defineProperty(this, "name", {         get: function () {             return name;         },         set: function (newName) {             name = newName;         },         enumerable: true,         configurable: true     });      this.sayName = function () {         console.log(this.name);     }; }  var person1 = new Person("Nicholas"); var person2 = new Person("Greg");  console.log(person1.name);    // Nicholas console.log(person2.name);    // Greg  person1.sayName();            // Outputs "Nicholas" person2.sayName();            // Outputs "Greg"   How is that the accessor property name can use the named parameter name to store its value? Isn't a local variable garbage-collected after the execution of its containing context (in this case, the Person constructor)?


Birthday Problem: Difference between Canonical Solution and Approximation

A couple weeks back, I was seeing if I could solve the basic formulation of the Birthday Problem (i.e. assuming 365 equally likely birthdays, what's the probability that, given a room of ${n}$ people, at least one pair of people share a birthday).  The initial solution that I used was to treat this as a binomial problem.  There are $\binom {n} {2}$ ways to pick a pair out of a room of ${n}$ people, and the probability of those two people not sharing a birthday is $\frac{364}{365}$. Thus, the probability of having no pairs of people in the room with a shared birthday is $\left(\frac{364}{365}\right)^\binom{n}{2}$, assuming that the probability of two people sharing a birthday is independent of all other pairs sharing a birthday.  Since we are interested in the probability of at least one pair of people, the final answer to the problem would be the complement of the above:  $$ 1 - \left(\frac{364}{365}\right)^\binom{n}{2}$$  In checking my work against the internet, I came across the accepted answer, which hinges on comparing each person in the room against anyone previously analyzed.  So the second person has a $\frac{364}{365}$ chance of not colliding with the first birthday, the third person has a $\frac{363}{365}$ chance of not colliding with the first and second birthdays, and so on.  Generalizing this comparison process to ${n}$ people, and then taking to complement probability, we get a final answer of:  $$ 1- \frac{\binom{365}{n} {n}!}{365^{n}}$$  My question: What is the initial solution above failing to take into account that makes it produce different results from the accepted answer?  I can see that the equations we derive for any room size ${n}$ within both solutions are different, but conceptually where does the initial solution break down?  If I had to take a guess, I would say that the problem with my initial solution lies in "assuming that the probability of two people sharing a birthday is independent of all other pairs sharing a birthday," but I'm still struggling to grasp why that independence assumption is invalid...  Any help would be appreciated.  Thanks!  P.S.  In case my explanation of the two methods was unclear, both are detailed on the . What I termed the "accepted answer" is detailed in the section "Calculating the Probability", while my "initial solution" is under the section "A simple exponentiation."


How to get the special string in JavaScript?

I want to get the special string in javascript. Example: JAMES SEVERA - 1679581110 - Physician/Psychiatry - 100 EAST BROADWAY, COUNCIL BLUFFS, IA 51503 Here are Doctor's name, position, and address. I just need the address only. (100 EAST BROADWAY, COUNCIL BLUFFS, IA 51503) I am going to use this address for the Google map.


Show improperly Riemman integrable function is not Lebesgue integrable

Let $$f(x)=\frac{\sin\left(\frac{1}{t}\right)}{t}.$$   Show that $\int^1_0 f(x)\,dx$ exists but $f\notin L^1$, i.e., on $(0,1)$ $f$ is  improperly Riemann integrable but not Lebesgue integrable.  Attempt:  Affirmation: $\int^1_0 f(x)\,dx$ exists (I am not very sure how to prove this either).  Now, using the following      Theorem: $f\in L^1 \iff |f| = f^+ + f^- \in L^1$   I can reduce the proof that $f\notin L^1$ by showing that either $\int^1 _0 f^+\,d\lambda = \infty$ or $\int^1 _0 f^-\,d\lambda = \infty$, but I haven't been able to show this either.


I have a valid Schengen visa from France, and I visited France couple of months ago. I would like to ask if I can access Cyprus without obtaining a Cyprus visa.   Is my Schengen visa enough?


What Desktop Environments are supported by Canonical except Unity?

I mean exactly Canonical supported in Ubuntu, not community-supported.


I have a variable named "event_id" that represents an event number. I want to run the script with a change of this variable from number 1 to number 65000. This means that the script will run in cycles and each time the variable "event_id" will increase the number by 1 until it reaches 65000. event_id="1" curl -k -u api:1234 https://localhost 'search=index=test eventid='$event_id''  Please your help


How $\left(1+\frac{1}{x}\right)^x $is differentiable

I try to use $f(x)= \frac{1}{x} $ and $g(x) = \left(1+x\right)^{\frac{1}{x}} $ . edit:for all $x \in \mathbb{N}$  Try to show $g \circ f$ differentiable.  I can get $f(x)$ is differentiable but I can't get $g(x)$  differentiable.  In other way I use $ f(x) = 1 + \frac{1}{x}$ and $g(x) = (x)^{\frac{1}{x-1}}$.  Have same problem It won't work on $g(x)$.  What should I do choose new $f(x),g(x)$  or prove in any other way.


I want to use the colours offered by \usepackage[dvipsnames]{xcolor}  in a beamer but I have an error: Option clash for package xcolor. \usepackage  I am using the following packages: \documentclass{beamer} \usetheme{Madrid} \usecolortheme{beaver} \usepackage{textpos} \usepackage{subfig} \usepackage{tikz} \usepackage{parallel,enumitem} \usepackage[export]{adjustbox} \usepackage[italian]{babel} \usepackage{ dsfont } \usepackage{tikz} \usetikzlibrary{positioning} \usepackage{varwidth} \usepackage{multicol}


How could Fully Homomorphic Encryption support power operations?

Fully Homomorphic Encryption (FHE) enables arbitrary functions computed on encrypted data, because it supports both addition and multiplication. But I wonder if FHE supports power operations.  For example:  $$C \leftarrow E(m)$$  $$y \leftarrow 2^C$$  $$2^m \leftarrow D(y)$$  I went over some FHE schemes like , it seems they don't support that.


Copying content between artboards in Photoshop

I often need to make banner sets that consist of anywhere from 6-14 different sized banners. A lot of these banners have the same text (which I put in smart objects to work faster) and the same or different images. The placement and sizes of these elements differ according to the banner size though.  I find the process of 'copying' the content from one artboard to another to go a bit slower than I'd like it to. I can't simply copy/paste, I have to duplicate the layer and then drag it to the right artboard in the layer panel. Hoping I have closed all my folders or else I have to drag miles upwards ;)   There has to be a better way! Why can't I simply copy paste a layer anymore? I'm pretty sure this used to be the case in older versions of photoshop.


Who wins a league (EPL) if two teams have the same number of points?

Is there any rule defined by UEFA or FIFA?     If more teams have the same number of points in a league after the finishing game, what is the rule to declare a winner??   Were there any rule updates by UEFA for this season (2013/14) or the upcoming season?  I found on the Premier League official website:   Here the rule is defined by goal difference. Is it a new rule, or is it determined by head-to-head then goal difference?


Advice on rehabilitating an unpopular Meta question (or not)

I recently submitted an . In very short order it has been downvoted to the point where it appears on the rogues gallery of downvoted questions (i.e. the last page of questions sorted by votes, with 50 per page). It also has by far the worst net-votes-to-total-views rating of all questions on that last page, which could be worst of all questions. Finally, although I can't see up/down vote totals for other questions with my rep, the fact that the question only has one upvote probably puts it in the running for worst up/down vote ratio amongst high net-downvoted questions.  While there are a few questions on the last page that might cause me to view my membership there as a badge of honor (e.g. ), I would, if possible, like to "improve the question". After all, that's how the system is supposed to work, right? I know I shouldn't radically change the question as that would violate SE's rules of integrity, but wanted to get your thoughts on the reasonableness of any of the following:   Change the title to fit MSO's convention of highlighting the key change under discussion rather than the twisted form of maintaining the status quo that is there now (ironically done in an attempt to avoid controversy) Remove the update about "agreement voting" not being allowed for discussion questions on the grounds that people don't like being lectured to, particularly from a relative newcomer and particularly about something that's been accepted practice for a long time Add an update which summarizes all the reasons why the embedded idea was a bad one Include a link to the popular  to emphasize that I've read that post as part of my research Leave the question alone and let it die, on the grounds that any more modifications at this point would be viewed as pandering and would be considered unwelcome


Want to install Unity in Lubuntu 16.04. Guide me please

I installed Lubuntu 16.04 by default because my computer system is old. I also want to try out unity in it. How should I do it? Thank you for helping me out.


Show Features for multiple Layers (Geoserver/Leaflet)

It's my first web mapping app and I want to show features for multiple layers added to my map, I'm using Leaflet/Geoserver.      var OpenStreetMap = L.tileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png');     var WorldImagery = L.tileLayer('http://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}');      var map = L.map('map', {             layers: [OpenStreetMap], /// fond de base             center: [30.412647, -9.579837],/// coordonnées             zoom: 13    //// zoom par defaut         });      var baseLayers = {         "Open Street Map": OpenStreetMap,         "World Imagery": WorldImagery     };      var parcelle_layer = L.tileLayer.wms("http://localhost:8082/geoserver/test_layer/wms", {         layers: 'test_layer:PARCELLE',         format: 'image/png',         transparent: true,         version: '1.1.0',         attribution: "myattribution"     });     var cadastr_layer = L.tileLayer.wms("http://localhost:8082/geoserver/test_layer/wms", {         layers: 'test_layer:mappe_cadastrale',         format: 'image/png',         transparent: true,         version: '1.1.0',         attribution: "myattribution"     });      var overlays = {         "PARCELLE": parcelle_layer,         "mappe_cadastrale_": cadastr_layer,         "Districts": district_layer,         "Quartiers": quartier_layer,     }; L.control.layers(baseLayers,overlays).addTo(map);   The problem I have is that I'm trying to get the name of the activated layer "lyr_active", for example when I select "parcelle_layer" I could get features for only this layer not for all layers when I click on map.      map.addEventListener('click', onMapClick);     popup = new L.Popup({maxWidth: 1000});     function onMapClick(e) {     var latlngStr = '(' + e.latlng.lat.toFixed(3) + ', ' +         e.latlng.lng.toFixed(3) + ')';     var BBOX =         map.getBounds()._southWest.lng+","+map.getBounds()._southWest.lat+","+map.getBounds()._northEast.lng+","     +map.getBounds()._northEast.lat;     var WIDTH= map.getSize().x;     var HEIGHT = map.getSize().y;     var X = map.layerPointToContainerPoint(e.layerPoint).x;     var Y = map.layerPointToContainerPoint(e.layerPoint).y;     var URL = 'http://localhost:8082/geoserver/test_layer/wms?SERVICE=WMS&VERSION=1.1.1&REQUEST=GetFeatureInfo&LAYERS='+lyr_active+'&QUERY_LAYERS='+lyr_active+'&STYLES=&BBOX='+BBOX+'&FEATURE_COUNT=5&HEIGHT='+HEIGHT+'&WIDTH='+WIDTH+'&FORMAT=image%2Fpng&INFO_FORMAT=text%2fhtml&SRS=EPSG%3A4326&X='+X+'&Y='+Y;     popup.setLatLng(e.latlng);     popup.setContent("<iframe src='"+URL+"' width='450' height='500'                 frameborder='0'></iframe>");     map.openPopup(popup);     }


How do i make an item, that can break certain block, and is named with command blocks in minecraft 1.16?

I am doing an prison escape map and i want to make an crowbar to destroy only iron trapdoors and is named crowbar. How???


On my laptop I want to install Ubuntu 14.04 but both my USB and CD drives are broken. I want to know how to install without needing the USB or CD. If you can help that is welcome.


Are there any herbs similar to or anything i can substitute marjoram with?


How to run Internet Explorer 7 on Windows 10

I have Microsoft Edge, but I need Internet Explorer 7 as a web site I am accessing will only open with this.  I downloaded Internet Explorer 7 and it said it was not compatible.  How do I make this work?


Is there a way to practice with weapons and buildings in Fortnite: Battle Royale?

I'd love to practice building structures or practicing with weapons without worrying about dying before I get a chance to use said weapons.   The problem is, I don't see a way to "practice" in Fortnite Battle Royale.  There's really no chance to practice in a match since shooting wildly gives away your position, or sometimes you just get bad luck and won't get the various other purple/gold tier weapons.  Is there a way to practice with weapons and buildings in Fortnite Battle Royale? Specifically offline?


A differentiable function with itself and its derivative converge to constants, can we conclude its derivative converge to zero

I have been struggled with the following problem.  Suppose that $f$ is differentiable on $(0, \infty)$. If we have $\lim_{x \rightarrow \infty} f(x) = c_1$ and $\lim_{x \rightarrow \infty} f'(x) = c_2$, where $c_1 c_2$ are two constants.  Can we get $c_2 = 0$？ If not could you please show me a counterexample?


Why use gradient descent with neural networks?

When training a neural network using the back-propagation algorithm, the gradient descent method is used to determine the weight updates. My question is: Rather than using gradient descent method to slowly locate the minimum point with respect to a certain weight, why don't we just set the derivative $\frac{d(\text{Error})}{dw}=0$, and find the value of weight $w$ which minimizes the error? Also, why are we sure that the error function in back-propagation will be a minimum? Can't it turn out the error function is a maximum instead? Is there a specific property of the squashing functions that guarantees that a network with any number of hidden nodes with arbitrary weights and input vectors will always give an error function that has some minima?


How to show that Klein four-group is a normal subgroup of the alternating group $A_4$

I want to show that the Klein four-group is a normal subgroup of the alternating group $A_4$.   I am using the information in , that shows explicitly $A_4$, and Klein four-group as a subgroup.  I know that there is the direct way, by definition, but is there a way that does not require actually multiplying so many permutations ?


Extract data to string from json in bash

How can I extract the ip address and the country and put them individual in a string without any quotes or any other characters which are present in the text by using the next command:  info_ip=`wget --tries=1 --timeout=10 -qO- http://ipinfo.io/?callback=callback; echo`   Now I'm looking to filter the data for ip and country  $ip = ?  $country = ?  ipinfo.io currently returns something like:  /**/ typeof callback === 'function' && callback({   "ip": "198.51.100.123",   "hostname": "host.example.com",   "city": "Example City",   "region": "Example Region",   "country": "XY",   "loc": "12.3456,-1.2345",   "postal": "XXX",   "org": "ASXXXX Example Organisation" });


I created spider web using curves. Then I joined all curves using CTRL + j. Then I wanted to apply "skin modifier" to create mash. Skin was added only to one line as shown in the picture. How to fix this?


Is it possible to create a path from an existing object animation?

Once you have an animated object using typical key-framing (other methods such as physics, driver or NLA apply too).  It could be useful to apply the motion to a path:   to adjust the evaluation time edit curve points points may be easier have many objects move along the same path. ability to follow the path.   Is there a way to do this?    Note that rotation and scale won't be taken into account.


PS4 controller now connecting? Reset doesn't work

I was using my PS4 perfectly fine last night and then I turned it all off to go to sleep. I woke up this morning and when I press the ps button on my controllers they simply flash a blue light and then go off- sometimes they flash continuously, after holding down the ps button but they do not turn my PlayStation on. I have two controllers and they both do the exact same thing. When I turn on the PlayStation on by the box, it tells me there has been a serious issue and it needs to restart but for that, I need to connect a controller and it doesn't work. Everything online tells me to press the restart button on the back on the controller and then connect them via USB but it still isn't working!!!! I am so confused, especially as it is the exact same with both my controllers and I was only using one last night. Pleaseeeee help


How does the movement enhancement from Mobile feat interact with the movement speeds of class and sub-class features?

The Mobile feat appears in the Player's Handbook (PHB, p.168) and would be generally accessible to all classes and races as long as DM agrees to allow feats at the table.  You are exceptionally speedy and agile. You gain the following benefits: • Your speed increases by 10 feet.  There are certain class or sub-class features that allow a PC to have increase in movement (walking) such as: a Barbarian's Fast Movement (+10 feet), a Monk's Unarmored Movement (+10 to +30 feet), or a Druid's Wildshape (walking, depending on the beast), a Scout Rogue's Skirmisher (reaction, moves half their speed). There are also certain class or sub-class features that modify existing or provide additional movement options other than walking, such as: Swarmkeeper Ranger's Writhing Tide (10 feet flying), Twilight Cleric's Steps of the Night (10 feet flying), or a Ranger's Deft Explorer (+5 feet; climbing/swimming speed sam as walking), a Druid's Wildshape (swimming/flying, depending on the beast), Phantom Rogue's Ghost Walk (10 feet flying), The Fathomless Warlock's Gift of the Sea (40 feet swimming). I'm looking for an answer for this specific question with relation to how the Mobile feat interacts with class/sub-class features which provide adjustments to movement speeds. From what I gather all these class/sub-class features would add a +10 feet movement, e.g. a Warlock with the The Fathomless sub-class who takes the Mobile feat would have a 50 feet swimming speed. Is this correct? Thanks for the clarification/confirmation on this.


How do I continue the Companions' quest line after "Blood's Honor"? (encountered the "Forever Mourning" bug)

I just finished the quest, "Blood's Honor" for Kodlak Grey-Mane, but there is an attack on the Companions before I can hand in the quest. Now, all the Companions NPCs are sitting and mourning all the time ("Forever Mourning" bug) and I can't get any new quests or anything.  How do I fix this and move forward in the quest line?


How to give the path of the .bib file in IEEEtran class?

Please excuse me it's a naive question that I am unable to troubleshoot. I am using the IEEEtran class with \bibliographystyle{ieeetran}. The reference file is in a different folder location than the main Latex file. My question is how to give the path of .bib file in the \bibliography{ } ? I googled and tried the following formats but didn't succeed. \bibliography{C:/Users/Dropbox (4)/Report-1/references.bib}{}  \bibliography{"C:/Users/Dropbox (4)/Report-1/references.bib"}{}  \bibliography{"C:\Dropbox(4)\Report-1\references.bib"}{}


I'm not sure if this exact question was asked before but here it is. I am currently on windows xp and would like to move to a version of Linux/Ubuntu like Ubuntu itself or Lubuntu or whatever is out there. Only thing is it should be easy for my parents to use it, as they are not so techie...! It should be kind of similar to xp and should be so buttery smooth.  Here are my current system specs: Pentium 4 2.8 GHz 20 GB dedicated for OS, whichever it is, rest 20 for personal use (total 40 GB HDD) RAM 1.4 GB Graphics 32 MB Wired internet connection Should have LTS or whatever it is called - for updates, so that I don't have to update/upgrade for a long time.  Please suggest me the best one with reason.


Trivial question: Is there any standard notation for the concatenation of two or more matrices?  Example:  $$A = \left(\begin{array}[c c]  - a_1 & a_2\\ a_3 & a_4  \end{array}\right),$$  $$B = \left(\begin{array}[c c]  - b_1 & b_2\\ b_3 & b_4  \end{array}\right),$$  Then the concatenation (by rows) of $A$ and $B$ is:  $$C = \left(\begin{array}[c c]  - a_1 & a_2\\ a_3 & a_4 \\  b_1 & b_2\\ b_3 & b_4  \end{array}\right).$$  I just want to know if there is a standard notation for this operation.


How was Thor able to dent Captain America's Shield?

I was reading about Adamantium on the      Proto-Adamantium   This is the original Adamantium created by Dr. MacLain. Proto-Adamantium is the official name for the metal that makes up Captain America's Shield. It has never been recreated and is the absolute most invulnerable item in all of existence.    This lead me to read about      The true shield was once slightly dented by an enraged Odinforce empowered Thor, using Mjolnir, but he later reconciled and pounded out the small dent.    Was the dent caused by Odinforce or Thor's Hammer? Is Mjolnir or Captain America's Shield "the absolute most invulnerable item in all of existence"?


Any idea why the piece of code below does not add the script element to the DOM?  var code = "<script></script>"; $("#someElement").append(code);


Choosing a bandwidth for kernel density estimators

For univariate kernel density estimators (KDE), I use Silverman's rule for calculating $h$:  \begin{equation} 0.9 \min(sd, IQR/1.34)\times n^{-0.2} \end{equation}  What are the standard rules for multivariate KDE (assuming a Normal kernel).


How to include line number and file name Console.WriteLine output?

Is there a way to include line numbers and file name in C#'s Console.WriteLine function?  For example, on the line 115 of file "myClass.cs" I have the statement  Console.WriteLine("Hello world");   I would like the output to be:  [myClass.cs][115]:  Hello world


What is the difference between these two casting methods in C++?

Let's say we have two classes Employee and Manager where Manager is derived from Employee. What is the difference between e2 and e3 (aside from one being a pointer)  Manager m; Employee e2 = m; Employee* e3 = &m;   I have noticed that if Manager overrides a virtual method print in Employee, then e2.print() invokes Employee::print whereas e3->print() invokes Manager::print() (i.e. polymorphism does not work without the pointer). But I'm not sure what exactly is happening here.


Irreducible polynomial in $\mathbb C[x_1,x_2]$ also irreducible in $\mathbb C[x_1,x_2,...x_r]$?

Let $f_1(x_1), f_2(x_2)$ be polynomials in a single variable, of relatively prime degree, with complex coefficients. If $f_1(x_1)+f_2(x_2)$ is irreducible in $\mathbb C[x_1,x_2]$, then is it irreducible in  $\mathbb C[x_1,x_2,...x_r]$ for every $r\ge 3$ ?


Choice function for a collection of nonempty subsets of $\{0,1\}^\omega$

Possible Duplicate:          Is possible to construct a Choice function for a collection of nonempty subsets of $X=\{0,1\}^\omega$? (Without AC)  Attempt:  We know an explicit injection $f\colon \mathbb{N}\to X$ is so easy to construct it, I think that a possible choice function $c$ is one which $c(X)=f(1)$, $c(X\setminus\{f(\{1,\ldots,n\})\} )=f(n+1)$, but I don't know how extend it (and I don't know if is possible to do) to all collection $P(X)\setminus\{\emptyset\}$.  This exercise comes from Munkres Topology chapter 1 section 9


What is the number of injective maps from a set of cardinality $m$ into a set of cardinality $n$ $(m \leq n)$?


Why isnt this add and remove class not working in JQuery?

Why is this not working? I'm going absolutely nuts.                            $('.fav').on('click', function() {                 $(this).addClass('item-selected');             });              $('.fav.item-selected').on('click', function() {                 $(this).removeClass('item-selected');             });   BELOW IS FULL CODE. It's the second part that wont undo.          $('.fav').on('click', function() {             $(this).addClass('item-selected').next('span.notification').toggleClass('show-notification').html("Hello world!");             setTimeout(function(){                 $('.show-notification').removeClass('show-notification');             },4000);         });          $('.fav.item-selected').on('click', function() {             $(this).removeClass('item-selected').next('span.notification').toggleClass('show-notification').html("Goodbye world!");             setTimeout(function(){                 $('.show-notification').removeClass('show-notification');             },4000);         });


Regular expression in Python - why the "\" is required to find a perod

For teaching purposes, I would like a good explanation and example of why the "\" is needed in searching for, say a period or a character that python may interpret differently. In the below example, I do NOT use a "\" to escape the "." and it still works fine. def checkfordot():     dotpattern="[.]"     searchingfor=input("Enter string:")     if (re.search(dotpattern,searchingfor)):         print("Has a dot")     else:         print("Does not have a dot")  Output: >>> checkfordot() Enter string:dfsdf. Has a dot >>> checkfordot() Enter string:ffsdfsdfsdf Does not have a dot >>>   In this case, using dotpattern="[.]" or dotpattern="[.]" doesn't seem to make much difference. Can someone a) explain why the above works without an escape and a simple explanation of what the escape does and in what situations b) provide an example or ideally two examples, integrated into my code, that demonstrates well why the escape character is required and how it is used for effective searching (or vice versa, in that without the "" the program would not work) Ironically, in typing this out - I noticed I had to escape the \ in order for it to be printed. Here I am typing: >: " \ \  " ....but it prints just one backslash >"\"


Find the smallest number of students for which the probability of a birthday duplicate is at least 0.5

Easiest way to approach this problem without dealing with nasty factorials


In a folder with many files how to do rm on lots of them

I just experimented a bit in linux and ended up getting very many files in one and the same folder. Now when I try to do      rm -f folder/*.png   I get      -bash: /bin/rm: Argument list too long   Is there some easy way to get past this?     Own work:  I suppose I could make an ugly script which loops through rm on the result of something like     ls /folder/ | head -100 | grep ".*\.png"   But really, there must be an easier Gnu way to do it?


Prove $\frac{11n^3 + 25n}{6}$ is an integer

Prove by induction that for every integer n, $\frac{11n^3 + 25n}{6}$ is an integer (i cant post the actual given expression since it might cause academic offence). I have only worked with proofs with natural numbers so induction was quite linear. For integers how do i go about showing that it is an integer. I tried cases where n = 1, 2, 3, -1, -2, -3 and it is all true but i dont know how to start it. Any insight would be appreciated. Thank you for your time.


Prove that $C^1([a,b])$ with the $C^1$- norm is a Banach Space

Consider the space of continuously differentiable functions, $$C^1([a,b]) = \{f:[a,b]\rightarrow \mathbb{R}\mid f,f' \text{ are continuous}\}$$ with the $C^1$-norm $$\lVert f\rVert := \sup_{a\leq x\leq b}|f(x)|+\sup_{a\leq x\leq b}|f'(x)|.$$ Prove that $C^1([a,b])$ is a Banach Space.   This was the proof we were given: Assuming $C^1([a,b])$ is a normed linear space all we need to show is completeness. Let $(f_n)$ be a Cauchy Sequence in $C^1([a,b])$ with respect to the $C^1$-norm. Then each $f_n,f'_n\in (C([a,b]),\|\cdot\|_{\sup})$. We know that $C([a,b])$ is complete and thus there exists $f,g\in C([a,b])$ such that $f_n\rightarrow f$, and $f'_n\rightarrow g$ (uniformly) with respect to $\|\cdot\|_{\sup}$. If we let  $$ F_n(x) = \int_a^x f_n(t)dt, \hspace{2mm}  F(x) = \int_a^x f(t)dt $$ then $F_n\rightarrow F$ uniformly because  $$\lVert F_n-F\rVert_{\sup}\leq \sup_{a\leq x\leq b}\int_a^x|f_n(t)-f(t)|dt\leq \lVert f_n-f\rVert_{\sup}<\epsilon.$$ From the fundamental theorem of calculus: $$f_n(x)-f_n(a) = \int_a^x f'_n(t)dt $$ Since $f'_n\rightarrow g$ uniformly then  $$ \int_a^xf'_n(t)dt\rightarrow \int_a^x g(t)dt $$ Since we know that $f_n\rightarrow f$ uniformly, $$f(x)-f(a) = \int_a^x g(t) dt $$ which by the fundamental theorem of calculues implies $f'=g$. So we know have $f_n\rightarrow f$ and $f'_n\rightarrow g=f'$ which mean $f_n\rightarrow f\in C^1([a,b])$ with respect to $C^1$-norm. So every cauchy sequence converges. Hence $C^1([a,b])$ is a Banach Space.   So I understand most of the proof. Where I get confused is that how did we actually show this satisfies the $C^1$-norm? Maybe I don't understand what this norm actually does.   Thank you for any help, comments and advice!


I've submitted an application to visit my unmarried partner in the UK during Christmas and the Embassy turned it down. My partner is British and I have Sudanese passport.    Entery clearance officer turned down my application because I don't have previous travel history to the UK or any other country with similar immigration system and cash deposit I have made before submitting my application. Regarding the money that he commented on it was a commission that received from work and I didn't submit any evidence where this money came from according to the entry clearance officer.    Can I re-apply for entry clearance again anytime soon? And how to avoid the refusal next time?


Ubuntu showing low disk space on file system root

I have installed Ubuntu-20.04 a couple of months ago (not VM). But now it is showing  this “low disk space” message. I am very new to Ubuntu. I do not know what to do now. I also use Windows 10 for other works. Can I increase partition size without  reinstalling Ubuntu? Or what should I do now? And since I am a beginner, I might have forgotten to mention any  important  details. Please let me know if I have. $ df -h    $ df -ih


How to activate an installed network driver

The ethernet connection suddenly stopped working after a restart happened. lshw -c network yields *-network UNCLAIMED. From what I've read in various forums, it would seem that no network driver is active. I searched the product RTL8111/8168/8411 and found that I needed the realtek r8168 driver. I downloaded and run the .deb file and everything seemed to be installed correctly. However after a restart and and a service network-manager restart nothing seems to be working. I ran lsmod but could not find the name of the driver I installed in the output. Any thoughts? Please forgive my inexperience, I will provide more info upon request. I have kubuntu 20.04 EDIT: sudo modprobe r8169 && sudo dmesg | grep r816 outputs: modprobe: FATAL: Module r8169 not found in directory /lib/modules/5.8.0-36-generic


findViewById() returns null on included layout?

I have an included layout in my activity's XML layout like so:  <include     layout="@layout/info_button"     android:id="@+id/config_from_template_info_btn"/>   I'm trying to set an OnClickListener for the button inside of that included layout by doing this:  findViewById(R.id.config_from_template_info_btn)         .findViewById(R.id.info_btn)         .setOnClickListener(new View.OnClickListener() {     @Override     public void onClick(View v)     {         //Do things     } });   However, this crashes on runtime with:  Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById(int)' on a null object reference   The info_btn.xml layout simply contains Button widget like so:  <merge xmlns:android="http://schemas.android.com/apk/res/android">     <Button         android:id="@+id/info_btn"         ...         /> </merge>   What am I doing wrong here?


Can I use my valid Schengen visa in old passport after i have new passport with new name?

I am a Russian citizen. I have Schengen visa type C valid till 01/03/2020 and I am going to change my name and I will keep my surname as it is.   Can I travel with my new passport with new name and old passport which has a valid Schengen visa in the new year to Europe?


Why this two spaces do not homeomorphic?

Consider $\Bbb Q$ with subspace topology and $\Bbb Q\times \Bbb Q$ with product topology. Why this two spaces are not homeomorphic?($\Bbb Q$ is the rational numbers)


MultiFile Add-on with single python file

I am making an add-on in blender that has one python file. In the past, I have been able to just import this add-on as a single python file by itself, but I need to use a .zip file for this because my add-on needs a .blend file to work. I have tried installing my current add-on as a zip with files as so: addon.zip: --addon.py --addon.blend  But the add-on doesn't show up in Preferences. How do I make this work? Thanks in advance!


HDMI: TV crops 16:9 from graphics card, 1-2 cm of image borders missing

The graphics card (Intel Iris graphics 6100) sends 16:9 video to the TV. 1-2 cm of its borders are cropped. How can I correct this?


Create Gradient that fits Above image both have same width 100% but width is different in view

I want to create an gradient over my image this is my html:

  CSS: .img-gradient {   content:'';   left:0; top:0;   width:100%;   height:100%;   display:inline-block;   position:absolute;   background: -moz-linear-gradient(top, rgba(0,47,75,0.5) 0%, rgba(255, 138, 0, 0.5) 100%); /* FF3.6+ */   background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(255, 138, 0, 0.5)), color-stop(100%,rgba(0,47,75,0.5))); /* Chrome,Safari4+ */   background: -webkit-linear-gradient(top, rgba(0,47,75,0.5) 0%,rgba(255, 138, 0,0.5) 90%); /* Chrome10+,Safari5.1+ */   background: -o-linear-gradient(top, rgba(0,47,75,0.5) 0%,rgba(255, 138, 0,0.5) 100%); /* Opera 11.10+ */   background: -ms-linear-gradient(top, rgba(0,47,75,0.5) 0%,rgba(255, 138, 0,0.5) 100%); /* IE10+ */   background: linear-gradient(to bottom, rgba(0,47,75,0.5) 0%,rgba(255, 138, 0, 0.5) 100%); /* W3C */   filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#002f4b', endColorstr='#00000000',GradientType=0 ); /* IE6-9 */ }  img-rounded and responsive are bootstrap classes result:


What does the “Current Period” data usage number mean?

In the Settings app, under Cellular > Cellular Data Usage, I see a “Current Period” value of 6.8 GB. However, I’ve checked this number several times over the years, at all different points in my cellular billing cycle, and it always hovers around 6 GB. Is this really the amount of data that I’ve transferred using my data plan since my last bill? If not, what does the number mean?


Getting an ItemCount with filtering in SP2013 using REST api

I am attempting to return an integer (itemcount) of the items within a SP2013 list. I have done this easily using the stock standard json method. However I have a need of counting the splist items which contain a certain value. My silly knowledge immediately lead me to try and use filtering with the ItemCount parameter only to find out that it will always still return the count for all items and it will completely ignore the filter. I have searched for a way of doing this but have found absolutely nothing other than a single page with a comment stating that it is not possible with the REST api and that it can ONLY be done using CSOM.  My question is, firstly, is it true that there is NO way to filter itemcount with REST? If so, how else can I obtain my item count using this type of filtering? (Examples or sources will help vastly) Thanks.  Below is my attempted request:  var itemid = item.id;           MyService.ensureFormDigest(function (fDigest) {               $http.get(                   MyService.appWebUrl + '/_api/web/Lists/getbytitle(\'Items\')/ItemCount?$filter=SubjectsID eq' + itemid,                   {                       headers: {                           'Accept': 'application/json; odata=verbose',                           'X-RequestDigest': fDigest                       }                   }).success(function (d) {                       item.itemcode = d.d.ItemCount;                       alert(item.itemcode);                       callback();                   }).error(function (er) {                       alert("Error getting List Item Count: " + er);                   });           });       }   On another note, I was advised to try it as such: /Items?$filter=SubjectsID eq 3&$select=Id  Then in the JS, in my success method:  data.d.results.length


apt command does not cache the .deb files?

When using apt-get to install or upgrade a package, a copy of that package (the .deb file) will be saved in: /var/cache/apt/archives  but when using apt command it's just download and installs the requested package and nothing will be saved in /var/cache/apt/archives.  Is it the default behavior of apt command? Is there any switch/config to makes apt cache the deb files? (to have a backup of deb files)  I'm running: ubuntu 16.04.2 LTS - With all updates.


What is the stastical perspective of regression?

When you giving a data set as a table. The rows are the observation (e.g. measurement of different humans) and columns are your features (height, weight, ...) and one column is the one you want to predict and you want to do regression. From a statistical perspective what are here the random variables? Is here each column a random variable and each value is in this column a realization? what needs to be i.i.d.?


VBA Excel 2007 help to speed up code to hide rows

I am trying to write a VBA code that automatically hides rows if a value in the row is equal to "". My range of values is A37:A400. Because my range is so big my previous VbA is to slow and looks one line at a time. Any ideas to make a fast code that will go though this large list and hide rows in a quick fashion. Right now it takes about a minute to hide the rows which is too Long.   Sub HideRows()     Dim cell As Range     For Each cell In Range("A37:A400")         If Not IsEmpty(cell) Then             If cell.Value = "" Then                 cell.EntireRow.Hidden = True             End If         End If     Next End Sub


I (and probably many other people) have accidentally clicked the wrong button in reviews. For example, I just clicked the Leave Open button when I wanted to click Close. I think many people have done this. I think an ability to undo this would be appreciated.


Prove that an infinite number of triangles can be inscribed in the hyperbola xy=c^2 whose sides touch the parabola y^2=4ax.

So I tried writing 3 equations of tangents to the parabola:  $t_1y+x=at_1^2$,  $t_2y+x=at_2^2$ and $t_3y+x=at_3^2$  The respective points of intersection are:  $(at_2.t_3,a(t_2+t_3))$, $(at_1.t_3,a(t_1+t_3))$ and $(at_1.t_2,a(t_1+t_2))$  Since these points lie on the hyperbola, Putting these points in $xy=c^2$:  $t_2.t_3(t_2+t_3)=\frac{c^2}{a^2}$ ...(1) $t_3.t_1(t_3+t_1)=\frac{c^2}{a^2}$ ...(2) $t_1.t_2(t_1+t_2)=\frac{c^2}{a^2}$ ...(1)   I am not able to figure out how to proceed after this... Can someone please help me out?


No matching function for call in template struct

there. I am new to C++ and trying to practice something with graph algorithm. I defined two structs in a class:    #include <vector> using namespace std;  enum GraphType{undigraph, digraph, undinetwork, dinetwrok};  template <class T> struct EdgeType {     T head, tail;     int cost;     EdgeType(T head, T tail, int cost)     {         this->head = head;         this->tail = tail;         this->cost = cost;     } };  template <class T> struct Edge {     T adjvex;     int lowcost; };  template <class T> class MGraph { private:     int vexnum, edgenum;     GraphType kind;     vector<vector<int> >edges;  //二维邻接矩阵     vector<T> vexs; //顶点表  public:     ...     void Prim(int v);       //Prim算法求最小生成树     void Kruskal(vector<EdgeType<T> > &tree);   //Kruskal算法构造最小生成树     int getMiniNum(Edge<T>* edges);     void getGraph(vector<EdgeType<T> > &graph);  };     and here are errors in my CPP file:    template <class T> void MGraph<T>::Kruskal(vector<EdgeType<T> > &tree) {     int i;     vector<EdgeType<T> > graph;     getGraph(graph);     tree.resize(vexnum-1);     ... } template<class T> void MGraph<T>::getGraph(vector<EdgeType<T> > &graph) {     graph.resize(edgenum);     int min = 0;     int k = 0;     int i,j;     for(i = 0; i < vexnum; i++)     {         for(j = 0; j < i; j++)         {             if(edges[j][i] < INFINITY && i != j)             {                 char s1 = graph[k].head = getVexValue(j);                 char s2 = graph[k].tail = getVexValue(i);                 int p = graph[k].cost = edges[j][i];                 k++;             }         }     }     EdgeType<T> e;     for(i = 1; i < edgenum; i++)     {         for(j = edgenum-1; j >= i; j--)                                                                                {             if(graph[j].cost < graph[j-1].cost)             {                 e = graph[j-1];                 graph[j-1] = graph[j];                 graph[j] = e;                 e = graph[j];             }         }     } }     C:\Windows\system32\cmd.exe /C "C:/TDM-GCC-64/bin/mingw32-make.exe -j4 SHELL=cmd.exe -e -f  Makefile" "----------Building project:[ test - Debug ]----------" mingw32-make.exe[1]: Entering directory 'D:/test/test/test' C:/TDM-GCC-64/bin/g++.exe  -c  "D:/test/test/test/main.cpp" -g -O0 -Wall  -o ./Debug/main.cpp.o -I. -I.  D:/test/test/test/MGraph.cpp: In instantiation of 'void MGraph<T>::Kruskal(std::vector<EdgeType<T> >&) [with T = char]': D:/test/test/test/main.cpp:57:17:   required from here D:/test/test/test/MGraph.cpp:368:2: error: no matching function for call to 'EdgeType<char>::EdgeType()' tree.resize(vexnum-1); ^ D:/test/test/test/MGraph.cpp: In instantiation of 'void MGraph<T>::getGraph(std::vector<EdgeType<T> >&) [with T = char]': D:/test/test/test/MGraph.cpp:367:16:   required from 'void MGraph<T>::Kruskal(std::vector<EdgeType<T> >&) [with T = char]' D:/test/test/test/main.cpp:57:17:   required from here D:/test/test/test/MGraph.cpp:415:2: error: no matching function for call to 'EdgeType<char>::EdgeType()' graph.resize(edgenum); ^  D:/test/test/test/MGraph.cpp:432:14: error: no matching function for call to 'EdgeType<char>::EdgeType()' EdgeType<T> e; ^  mingw32-make.exe[1]: *** [Debug/main.cpp.o] Error 1 test.mk:93: recipe for target 'Debug/main.cpp.o' failed mingw32-make.exe[1]: Leaving directory 'D:/test/test/test' mingw32-make.exe: *** [All] Error 2 Makefile:4: recipe for target 'All' failed 7 errors, 29 warnings     I don't know how to fix this, would anyone please help me out here? Thanks a lot!


I have a Dell Vostro 3500 and I have a lot of problem in Linux Mint 12 Lisa. The laptop overheat and shuts down when I have a lot of processing.  I read that the problem is because of the video drivers and the two video cards. The embedded intel can not be desabled.  Can anybody tell me if this problem is solved in Ubuntu?  Thanks, Manuel


Is bounce rate of a website a ranking factor?

I have heard this from many SEO experts that a website with less bounce rate will rank well on Google. But what if the website does not use any analytics tools to calculate bounce rate, how will then Google know the bounce rate of the website and rank it higher


Typesetting annuity and life-insurance symbols in ConTeXt

How do I typeset annuity and life-insurance symbols, actuarial notation in ConTeXt. I see there are packages available but not for ConTeXt.    Thanks


Trigonometry - simplifying a given equation

Question: $$\tan 9 - \tan 27 - \tan 63 + \tan 81$$  Answer I'm getting : 0  What I did: Well I clubbed together $\tan 9$ and $\tan 81$ and $\tan 27$ and $\tan 63$ (took out negative as common). Then using the identity for $\tan (A+B)$, I rearranged to formula to get what $\tan A + \tan B$ is. With that I'm getting zero multiplied by $\tan 90$. Since anything multiplied by zero, even infinity, is zero, I guess it should be zero.  I'm pretty sure my logic fails me somewhere, please tell me where (probably in the infinity and zero multiplication part)


executing cmds on a Linux box from a windows box

How can I create a script on a windows box that retrieves data from the Linux box by executing cmds against the remote Linux box?   I have got putty and Plink on the win box but not sure how to fire the cmds from a script e.g. a bat file and get the results written back to a txt file on the win box.  How would I do this for something simple like a grep or ls cmd for example?


-bash: cannot create temp file for here-document: Permission denied

This error recently appeared on my Raspberry Pi. I get this error when I try to autocomplete folder paths. It won't autocomplete commands at all. I don't get this error when I'm logged in as root.  When I do df -i I get:  Filesystem     Inodes  IUsed  IFree IUse% Mounted on /dev/root      399840 157845 241995   40% / devtmpfs       117383    394 116989    1% /dev tmpfs          118466      1 118465    1% /dev/shm tmpfs          118466    570 117896    1% /run tmpfs          118466      8 118458    1% /run/lock tmpfs          118466     10 118456    1% /sys/fs/cgroup /dev/mmcblk0p6      0      0      0     - /boot tmpfs          118466      4 118462    1% /run/user/1000   When I do df -h I get:  Filesystem      Size  Used Avail Use% Mounted on /dev/root       5.9G  5.7G     0 100% / devtmpfs        459M     0  459M   0% /dev tmpfs           463M     0  463M   0% /dev/shm tmpfs           463M  6.5M  457M   2% /run tmpfs           5.0M  4.0K  5.0M   1% /run/lock tmpfs           463M     0  463M   0% /sys/fs/cgroup /dev/mmcblk0p6   65M   21M   45M  32% /boot tmpfs            93M     0   93M   0% /run/user/1000   So it seems like my root is out of storage. I already removed files and uninstalled packages but nothing seems to change the outcome of df -h.  Please help, what am I doing wrong? Thanks in advance.  EDIT:  du -smh / gives me:  du: cannot access ‘/proc/2667/task/2667/fd/3’: No such file or directory du: cannot access ‘/proc/2667/task/2667/fdinfo/3’: No such file or directory du: cannot access ‘/proc/2667/fd/4’: No such file or directory du: cannot access ‘/proc/2667/fdinfo/4’: No such file or directory 5.7G    /


There are $2n$ players in a chess tournament. The first round consists of pairing the players to participate in $n$ matches with every player playing one match. In terms of $n,$ how many ways can this pairing take place?  The first pair of people can be chosen from $\binom{2n}{2}.$  Since we chose the first pair, the next pair will be chosen from an amount of $\binom{2n-2}{2}.$   This pattern continues till $\binom{2}{2}$ which is for the $n$th pair.  Hence, the pairings will be $$\binom{2n}{2}\cdot\binom{2n-2}{2}\cdot...\cdot\binom{2}{2}.$$  Dividing by $n!$ gets the ways $2n$ people can be chosen to play $n$ games.  How do I simplify this?


How to change critically low battery value?

I would like my laptop to hibernate itself when the battery level is 10% to be sure it has enough power to complete the operation properly. Actually if I don't pay attention my laptop informs me it will hibernate when it's too late, so instead it brutally shuts down. This kills lithium batteries and is not acceptable.


I have a Python  object. What is the best way to subtract one day?


How can I install MongoDB on  my Ubuntu 17.04??  Looks like there are no packages provided by Mongo at the moment, just wondering if someone has already managed to install an instance on 17.04?


A inverse Trigonometric multiple Integrals

How to calculate the closed form of the integral $$\int\limits_0^1 {\frac{{\int\limits_0^x {{{\left( {\arctan t} \right)}^2}dt} }}{{x\left( {1 + {x^2}} \right)}}} dx$$


There is a famous citation that says "It is evident that the primes are randomly distributed but, unfortunately, we don't know what 'random' means." R. C. Vaughan (February 1990)  I have this very clear but rather broad question that might be answered by different opinions and view points. However, my question is really not targeting an intuitive or philosophical answer, and I beg you for view points with a strength of mathematical foundation.   are primes randomly distributed?  so then what is 'random' in this context?    A posterior I  A possible hint comes perhaps from the theory of complex dynamical systems.  It can be difficult to tell from data whether a physical or other observed process is random or chaotic, because in practice no time series consists of pure 'signal.' There will always be some form of corrupting noise, even if it is present as round-off or truncation error. Thus any real time series, even if mostly deterministic, will contain some randomness. All methods for distinguishing deterministic and stochastic processes rely on the fact that a deterministic system always evolves in the same way from a given starting point.(ref , , , and "") - complying to latter, remind that every prime $p$ can be trivially identified by a sieving that applies prior primes $q<p$ so it is possible to determine that somehow the system evolves in the same way from a given starting point. Of course to take into account that time must be substituted by a walking index as well.    A posterior II  Thank you for all of many the comprehensive answers and discussions. This is a quite classic question on MSE and meanwhile we moved much forward. You are right that primes are not random as per above question. Indeed we could show that they are in their sequence some type of "deterministic chaos". We don't need the Riemann function for this purpose. The primes sequence is a so called "ordered iterative sequence". Meanwhile this has been further elaborated by this source: "The Secret Harmony of Primes" (ISBN 978-9176370001)  Some of you correctly referred to sieving. It is crucial however that we regard sieving procedures as a subset of "interference" (incl. frequencies and amplitudes). We can iteratively apply interference rules in order to gain from the first prime 2, the next ordered sequence. This can be iterative continued in an "ordered" way and within exact boundaries of p-squares (for 100% certainty). Indeed, in order to construct an ordered sequence of primes you just need to begin with 2. The Riemann approach is charming but would raise difficulties since we don't have yet a proof of the hypothesis that connects the order of the non-trivial zeros with the primes. So if you apply Riemann, as some colleagues here suggest, we would need to say at any time in the begin of your argumentation something like "provided the Riemann hypothesis would be true...". Having in mind that the very unique rule that primes follow, is that in an interference scheme all odd prime frequencies dance on the base frequency of 2 (ordered iterative sequence), one may even give it a thought to something of a parallel in the Riemann transformed world, that all non-trivial zeros dance on 1/2. But latter remains not more than a tempting trivial speculation yet.


I'm in the US for 30 days and got a SIM card from Lycamobile. For some reason adding APNs doesn't work through the GUI (I add them but they never show up in the list, even after rebooting).  Instead I added the following lines to my /system/etc/apns-conf.xml, just before </apns>    <!-- BEGIN Custom APNs -->                                         <apn carrier="Lyca US" mcc="311" mnc="960" apn="data.lycamobile.com" type="GPRS" user="lmus" pass="plus" />   <!-- END Custom APNs -->     Based on MCC and MNC data from Wikipedia and the information available online in general. I also enabled Data Roaming and International Roaming. I have rebooted my phone. I am on a Samsung Galaxy S3 running the latest AOKP nightly.  However, I still get an R in my signal tray and cannot connect to the internet. Please advise - any help would be appreciated even if it a nudge in a new direction.  Cheers,  Gausie


what does generator's yield return in python and how is this different from return

I am really confused as what does keyword "yield"  return in generator? what are the real use case of this, when should i use it.  how is it different from "return" keyword?  what i have learnt is generator is better in term of performance but i cannot think of any real use case, if asked in interviews !  Thanks in advance!


All lines are working except the last one, saying no operator "+" matches the operands

#include <iostream> #include <vector> #include <string> std::string likes(const std::vector<std::string> &names) { if (names.size() == 0) return "no one likes this"; else if (names.size() == 1) return names[0] + " likes this"; else if (names.size() == 2) return names[0] + " and " + names[1] + " like this"; else if (names.size() == 3) return names[0] + ", " + names[1] + " and " + names[2] + " like this"; else if(names.size() > 3) return names[0] + ", " + names[1] + " and " + (names.size()-2) + " others like this"; /*this line isn't working, i guess the problem is in names.size() */  The last line is causing my application to not run, i have tried every possible way i know to solve this but nothing really helped, can you please help?


Is there any difference between math mode and text mode for numbers?

Take the sentence: "The answer is 42". Is there any difference between  The answer is $42$.   and  The answer is 42.   In the final PDF I cannot see any difference. Does it make a difference whether I use math mode or text mode for numbers? If so: What shall I use?


I was trying to log into my gmail account when it said "looks like your signing in from an unusual location" then asked me to do step 2 verification. The strange thing about it is that the phone number and security question they asked are not any that I have set up and I am also using the same computer and internet I use every day. Please help me understand this, anyone!


Why do Klingons in ENT look different than in TOS?

Why do the Klingons in ENT look different than the Klingons in TOS?  I understand the explanation for the difference after TOS, but since ENT is before TOS.


Blowfish Encrypt and Decrypt char buffers

i'm try to get a bowfish function working for simple char buffers. The program fails when I try to decrypt an encrypted buffer and fails on the EVP_CipherFinal_ex() call.  #include <string.h>  #include <openssl/evp.h>  #include <openssl/buffer.h>  #include <openssl/blowfish.h> #include <openssl/evp.h>  int do_crypt(unsigned char *inbuf, int inlen, unsigned char *outbuf, int *outlen, int do_encrypt) {       outbuf=(unsigned char*) malloc(inlen+EVP_MAX_BLOCK_LENGTH);       int tmplen=0;       unsigned char key[] = "0123456789";       unsigned char iv[] = "12345678";        EVP_CIPHER_CTX ctx;       EVP_CIPHER_CTX_init(&ctx);       EVP_CipherInit_ex(&ctx, EVP_bf_cbc(), NULL, NULL, NULL, do_encrypt);       EVP_CIPHER_CTX_set_key_length(&ctx, 10);       EVP_CipherInit_ex(&ctx, NULL, NULL, key, iv, do_encrypt);        if(!EVP_CipherUpdate(&ctx, outbuf, outlen, inbuf, inlen)) {           /* Error */           printf("* update failed *\n");           EVP_CIPHER_CTX_cleanup(&ctx);           return 0;       }        int db=*outlen;        if(!EVP_CipherFinal_ex(&ctx, outbuf+db, &tmplen)) {           /* Error */            ERR_print_errors_fp(stderr);           printf("* finalise failed *\n");           EVP_CIPHER_CTX_cleanup(&ctx);           return 0;       }         (*outlen)=db+tmplen;        EVP_CIPHER_CTX_cleanup(&ctx);        return 1;  }  int main(int argc, char **argv) {       char *plain="ENCRYPT DECRYPT this string";       int plain_len=strlen(plain);       unsigned char *cipher;       int cipher_len;        printf("***** ENCRYPT *****\n");       if (!do_crypt((unsigned char*) plain, strlen(plain), cipher, &cipher_len, 1)) {           printf("failed to encrypt\n");           return 1;       }        char *decrypt;       int decrypt_len;       printf("***** DECRYPT *****\n");       if(!do_crypt(  cipher ,cipher_len , decrypt, &decrypt_len, 0)) {           printf("failed to decrypt\n");           return 1;       }  printf("decrypt=\"%s\"\n",decrypt);   printf("decrypt_len=%d\n",decrypt_len);       return 0;  }    any help would be much appreciated.


If I surrounded a black hole with gravitometers and observed the gravitational field as mass passed the event horizon, what would I observe?

By surrounding a black hole with gravitometers I would be able to get a 3-D map of the gravitational field. If I observed this field as an object approaches the event horizon, what would I see?  Would the gravitational field allow me to track the mass on its journey from the event horizon to the singularity? Would this allow me to observe what is going on inside the black hole?  To clarify: At some point in time there are two distinct gravitational fields, one for the approaching object and one for the singularity. At a later time there is just the gravitational field for the singularity. It is the nature of the transition in the gravitational field that I am specifically interested in.


wmctrl -s can be used to switch between virtual desktops. Is there a command that shows the desktop? that is a command that will switch between minimizing all windows and restoring them?