Symmetric Difference Approximation of a Measurable Set

Let $(\Omega,\mathcal{F},P)$ be a probability space and $\mathcal{A}$ be an algebra of subsets of $\Omega$ such that  $\sigma(\mathcal{A})=\mathcal{F}$. Prove that for all $B\in \mathcal{F}$  and for all $\varepsilon >0$ there is $A\in \mathcal{A}$ such that $P(B\bigtriangleup A)<\varepsilon,$ where $B\bigtriangleup A:=(A\setminus B)\cup (B\setminus A)$ is the symmetric difference of $A,~B.$  I have tried proof by contraposition, by assuming the existence of a set $B \in \mathcal{F}$ and an $\varepsilon>0$ such that $P(B\bigtriangleup A)\geq \varepsilon,$ but this doesn't seem to get me somewhere. On the other hand, for a straight proof, the construction of the desired set $A$ seems foggy, since I don't know how to start.   Thanks a lot for the help!


invalid server name or wildcard in a virtual host in nginx

I have the following virtual host configuration for nginx in a virtual host:  server {         listen 80 default_server;         listen [::]:80 default_server;          server_name angularindepth.com         rewrite ^/(.*)$ https://blog.angularindepth.com/$1 redirect; }   But when I run nginx it gives me the following errors:        [warn] 5007#5007: server name "^/(.*)$" has suspicious symbols in ...   [warn] 5007#5007: server name "$1" has suspicious symbols in ...   [emerg] 5007#5007: invalid server name or wildcard "^/(.*)$" on   0.0.0.0:80      I've googled and all questions seem to be around server_name directive, whereas in my case it contains a proper name. The problem seems to be with rewrite directive. Am I right? What's the problem?


I'm rather inexperienced to LaTeX and I have run into an issue regarding ToC.  I have a report with an appendix.  I wish to have a standard ToC over the report, and only show the chapter "Appendix" in this ToC.  In my Appendix I would like another ToC containing the appendix and only the appendix.  Something like this:   ToC1 Capter1............1   section1.........1   section2.........3 Chapter2...........5   section1.........5 ChapterAppendix...10  ToC2 ChapterAppendix ..10  Section1.........10   Subsection1.....11   I have tried following this example:  but without luck.  Can someone give me a clue on what to do?


Trying to copy to clipboard from command line by using command:  xclip /etc/apt/sources.list   Trying to get out from clipboard:  xclip -o   This prints the content of sources.list and it is fine.   But now I try to paste into eclipse project and got some old clipboard content. Looks like xclip uses its internal clipboard.  How to copy into system clipboard from command line?


Undefined symbols for typedef and template?

This seems so simple, but I cannot figure out what's wrong. I'm implementing the C++ vector class (only for int, not a template), and functions with iterator templates or typedefs are giving me these errors on compile:  Undefined symbols:   "void vectorInt::assign<int>(int, int)", referenced from:       _main in ccNVdR23.o   "void vectorInt::assign<int*>(int*, int*)", referenced from:       _main in ccNVdR23.o       _main in ccNVdR23.o ld: symbol(s) not found collect2: ld returned 1 exit status   Important parts for the source files are:  vectorInt.h  #include <cstdlib> #include <stdexcept>  typedef unsigned int size_type;  class vectorInt { private:     int* array;     size_type current_size;     size_type current_capacity; public:     .     .     .     template <class InputIterator>         void assign(InputIterator first, InputIterator last);     void assign(size_type n, const int u); };  #endif // VECTORINT_H   vectorInt.cpp  #include vectorInt.h . . . template <class InputIterator> void vectorInt::assign(InputIterator first, InputIterator last) {     clear();     InputIterator it = first;     int count = 0;     while(it++ != last) {         count++;     }      reserve(count);     while(first != last) {         this->push_back(*first++);     } }  void vectorInt::assign(size_type n, const int u) {     clear();     reserve(n);      for(int i=0; i<(int)n; i++)         push_back(u); }   main.cpp  #include <cstdlib> #include <stdexcept> #include <iostream> #include "vectorInt.h"  using namespace std;  int main(int argc, char** argv) {     vectorInt first;     vectorInt second;     vectorInt third;      first.assign(7, 100);      vectorInt::iterator it;     it = first.begin()+1;     second.assign(it, first.end()-1); // the 5 central values of first      int myints[] = {1776,7,4};     third.assign(myints, myints+3);   // assigning from array.        return 0; }   FYI: I know the main method uses the vectorInt::iterator, but that is not the problem and hence I didn't include it in the source code.


If $11z^{10}+10iz^9+10iz-11 = 0$. Then possible value of $\mid z \mid,$ is  $\bf{My\; Try::}$ Given $11z^{10}+10iz^9+10iz-11 = 0\Rightarrow \displaystyle z^9 = \frac{11-10iz}{11z+10i}.$  Now Put $z = x+iy\;,$ we get $\displaystyle (x+iy)^9 = \frac{11-10i(x+iy)}{11(x+iy)+10i} = \frac{(11+10y)-10ix}{11x+i(10+11y)}$  Now i did not understand how can i solve it,  Help Required  Thanks


When speaking of an airline ticket, I have heard the term open ticket which has to do with dates not being fixed I believe.   What exactly is an open ticket? How do you get an actual flight from one? What are typical restrictions?


How do you setup remote accounts to a server?

How can I have an Ubuntu client login to an account in Ubuntu server and have all their files on the server? I only want to have Ubuntu installed on the client PC but since it has an SSD it has a very limited space.  Alternatively, it would be even better if the client could network boot an Ubuntu instance from the server but I don't know if that's possible since the Desktop is wireless so I'm assuming I can only have the client have Ubuntu installed in the SSD  I'm looking for a step by step solution on how to do all this


I have ubuntu 13.10 and I am trying to use a disk that contains a book, How to program Java, 7th edition. It is the Linux version CD and I can't figure out what program to use so I can look at the files on it.   All of the files are in .class format. I have used the windows version on another pc and it seems to work fine with jgrasp, is there something else I should be using to edit and create java programs with the .class extension?


Some website pages not indexed by Google although followed the recommended steps

I have built a website (www.shareall.nl) in wordpress and did some SEO (metadescriptions, headings, links, alt text, microdata, sitemap, robots.txt, etc) using Yoast Wordpress SEO plugin. I did not squeezed everything out of it but the site ranks pretty well in Google on important keywords regarding Prezi (top 5).  The problem however is, that there is a set of pages that are not being indexed and these pages are relevant to my customer? One of the pages is  (I cannot post more links due to my reputation on stackoverflow, but they are all about training).   I know (as the moderator told me) that there is another question about this topic but I have followed all recommendations given there without success. I would like to get more ideas of what to try and hope someone can help me with this.  This is what I have done so far or are some facts about the site which might be relevant:  submitted sitemap and saw most of the pages being indexed robot.txt is not preventing pages from being crawled manually crawled pages using google's webmaster tools and submitted them afterwards the website itself has multiple links from other pages towards the training pages don't have noindex set for concerned pages domain is not new and exists for numerous years now (since 2011) the website is new and is launched this year (february 2014) I have multiple links within the site pointing to the missing pages  Again any help is greatly appreciated!


Questions about some American English vocabulary

I was wondering if any American writers could give me some advice as to whether the following expressions/vocab are used and understood in the US:  (words in bold are the ones I'm asking about. Some words are also in inverted commas)   The living room of a house -- is this expression ok? Do you ever say "front room" or "sitting room"? If it's a massive house with a huge entertainment area, can you say "living area"? I was tickled -- is this expression ok? It means happy. "My college mate wants to hang out at my digs" - meaning my place, or college dorm. Would digs be used? Is college mate an ok expression for someone you go to college with? In the real world, do people stop on the shoulder or the hard shoulder of a highway or is either fine? Is median strip used for the partition between 2 lanes of a highway going in different directions? "He takes the piss out of every banker he meets" -- meaning he mocks them. Is this used? Can you say "I'm pissed off at him" (angry) or does it have to be: "I'm pissed at him." "I called my parents' landline (fixed home phone)." Is landline ok? "I tried on the jeans in the changing room." Is this ok or does it have to be fitting room or something else? Is the word "thingamajig" used in American English? "I can't walk on my ropey leg" -- meaning damaged or injured or tired. Can ropey be used? Security guards are surveilling the place. This verb is showing up as misspelt but I see it sometimes. Is there another spelling or verb?   13.In the real world, do people in the US use MPH or KPH as the unit of speed when driving?   Is the expression "Calm my jitters" acceptable? (calm my nerves) If you pull up to a mansion surrounded by a fence with very thick metal bars all around it, is the word "fence" appropriate or is there a better word. I think that gate would only be for a door in a fence or something? Is the expression "It cost a pretty penny" ever used in the US? Is the expression "It took every ounce of strength" used in the US? Can the word "skiff" be used in the US for a sort of flat-bottomed row boat?   Thank you so much to anyone willing to give advice about these points. Though I appreciate any input, I think it would be most useful to hear from actual American writers to avoid possible confusion.   Many thanks!  Follow up questions:  Thanks to all those who gave their very useful opinions. I have a couple more questions for anyone willing to give advice:   What do you call the area (let's say on the 10th floor) in front of an elevator door? Is there a specific word like "the landing"? When you enter a house (without a mud room), there is a space just past the front door which is not really a room, but it's like the entrance way/hallway between the front door and other rooms like the living room, study. Is this called a "hallway"? It's not a lobby, obviously as that would be for a hotel or something. Can it be the "entrance hall"? If you are using WASP-y as an adjective, do you have to write it like "WASP-y" or "WASPy". I'm guessing "waspy" hasn't become a thing yet?   Thank you!


Is there add-on to skip rendering for identical frames?

I've googled a lot about it, but everyone suggests to skip them manually. It's not easy.  Maybe there is some add-on or script to make Blender render identical frames only once? And then I can make the needed frames longer using video editors. It could save many hours of rendering.


Plurals: Is it live or lives and Is it work or works in this example?

Which is correct?     The Maritime Quarter Residents' Association support and represent everyone that live and work in the Maritime Quarter.   or     The Maritime Quarter Residents' Association support and represent everyone that lives and works in the Maritime Quarter.


How do I automatically backup a file to OneDrive?

I have an important file in c:\users\me\app\roaming\foo\, is there any way to mark it so that it automatically syncs to onedrive?  edit: Other solutions involve scheduled backups to the OneDrive directory. I would rather not use additional tools and would like to have the directory sync automatically (to take advantage of change detection and instantaneous sync). I ended up using mklink.


Is the electric field of a volume charge distribution well defined?

Consider a volume charge distribution $\rho({\bf r'})$. The electric field at ${\bf r}$ is  $${\bf E}({\bf r})=\iiint\frac{1}{4\pi\epsilon_0}\frac{\rho({\bf r'})}{R^2}\hat{\bf R}\, \mathrm d^3{\bf r'}$$  where ${\bf R}={\bf r}-{\bf r'}$.  My question is at positions ${\bf r}$ where $\rho \ne 0$, the integrand blows up when ${\bf R}={\bf 0}$. But I know from EM textbooks that ${\bf E}({\bf r})$ at where $\rho({\bf r})\ne 0$ is well-defined.  Can one explain this mathematically?  Edit: Here is own thought, but I am not sure whether it's correct.  Consider this as a purely mathematics question first.  Then I think the question is similar to whether $$\int_0^1\frac{1}{\sqrt{x}}dx$$ is undefined or equals $2$.  In my opinion, strictly speaking, the above integral is undefined, because the integrand is undefined at $x=0$.  However, since $$\lim_{\delta\rightarrow0^+}\int_\delta^1\frac{1}{\sqrt{x}}dx=2$$ we usually just say $$\int_0^1\frac{1}{\sqrt{x}}dx=2$$  So in my opinion, when we write $${\bf E}({\bf r})=k\iiint\frac{\rho({\bf r'})}{|{\bf r}-{\bf r'}|^2}\hat{\bf R}d^3{\bf r'}$$ we are actually saying $${\bf E}({\bf r})=\lim_{\delta\rightarrow0^+}k\iiint_{D_{\delta}}\frac{\rho({\bf r'})}{|{\bf r}-{\bf r'}|^2}\hat{\bf R}d^3{\bf r'}$$ where $D_\delta$ is the space minus a ball with radius $\delta$ centered at ${\bf r}$.  It can be shown that if $\rho({\bf r})$ is finite or does not go to infinity $\textit{too fast}$, then the limit exists.  If the above is true, then the physics question one should ask is whether this gives the correct answer in physics.  In classical EM, the $\textit{macroscopic}$ field ${\bf E}$ is in fact the average of the $\textit{microscopic}$ field ${\bf e}$. (Landau and Lifshitz, $\textit{Electrodynamics of Continuous Media}$, p.1.)  So you can consider ${\bf E}({\bf r})$ as the average of ${\bf e}$ over a ball with radius $\delta$ centered at ${\bf r}$.  Now, it can be shown that  (1) the average field over the ball due to charges outside the ball is the same as the total field due to all charges outside the ball at the center of the ball, and  (2) the average field over the ball due to charges inside the ball is $$-k\frac{{\bf p}}{\delta^3}$$ where ${\bf p}$ is the total dipole moment inside the ball.  (Griffith, $\textit{Introduction to Electrodynamics}$, p. 156-157, problem 3.41).  So when $\delta$ is small macroscopically, ${\bf p}\rightarrow{\bf 0}$, and we have $${\bf E}({\bf r})=k\iiint_{D_{\delta}}\frac{\rho({\bf r'})}{|{\bf r}-{\bf r'}|^2}\hat{\bf R}d^3{\bf r'}$$


I get the Error      Type of conditional expression cannot be determined because there is no implicit conversion between 'System.DateTime' and'System.DBNull'   with the Code (in the 3rd line)  DateTime? BirthDate = GetDate(PersonID); System.Data.SqlClient.SqlCommand myCommand = new System.Data.SqlClient.SqlCommand(cStatement, myConnection); myCommand.Parameters.AddWithValue("@BirthDate", BirthDate.HasValue ? BirthDate.Value : DBNull.Value);   How can i avoid this error?


Is it polite or annoying to send a professor a short "Thanks" email?

After asking a professor a question through e-mail and receiving an answer, is it polite that a student send a short e-mail simply saying "Thanks" as an acknowledgment that the answer was received and appreciated? I'm thinking of sending this but am not sure if it might be considered annoying or unnecessary  (as I'm not sure how busy the professor is, or how many emails he/she has to sort through every day.)  Is there some widely agreed-upon etiquette for this?


Protected vs protected internal (Again) in c#

I am raising a question (again) on the protected vs protected internal as I am still unsure and not able to get a grip on them.  Any help is much appreciated.  // DLL 1   namespace Assembly1   {     class class1 : class2     {       static void Main()       {          new class1().Test();       }        private void Test()       {          Console.WriteLine(this.sample);       }     }  }   // DLL 2    namespace Assembly2     {         public class class2         {           // protected string sample = "Test";                         protected internal string sample = "Test";         //Same behavior when using protected and protected internal. Why ?      } }   I am getting the same behaviour for both the lines.        // protected string sample = "Test";                     protected internal string sample = "Test";   But I am sure that there should be some difference.     MSDN says:   Protected: Access is limited to the containing class or types derived from the containing class.      Protected Internal:  Access is limited to the current assembly or types derived from the containing class.   I am able to access both protected and protected internal from outside assemblies as long as I inherit from the base class.   Pretty confusing! both looks exactly similar. Can any one explain me by modifying from the above example ?


non-static method openInputFile(String) cannot be referenced from a static contex java

Here is my code in question:  public File openInputFile(Scanner kb) {   if(kb == null)   {         throw new RuntimeException("ERROR! Scanner Not Detected.");   }   System.out.print("Enter Name of File: ");   String fn = kb.nextLine();   File inf = FileUtil.openInputFile(fn);    return inf; }   I am getting the following error:  FileUtil.java:33: error: non-static method openInputFile(String) cannot be referenced from a static context       File inf = FileUtil.openInputFile(fn);                           ^   Nothing is static, so I'm not sure why I'm getting this error. Can anyone help?


I have Below Query From Parent Id to child, but getting the below error. Please help me out with this one.  Query  Select id,        (Select id,Type__c,Document_Attached__c,Opportunity__c from Top_X_Designation__r),         Handoff_Attached__c  from Opportunity   Error I am getting     Document_Attached__c,Opportunity__c from Top_X_Designation__r),                                            ^   ERROR at Row:1:Column:71   Didn't understand relationship 'Top_X_Designation__r' in FROM part of query call. If you are attempting to use a custom relationship, be sure to append the '__r' after the custom relationship name. Please reference your WSDL or the describe call for the appropriate names.   Both the object Opportunity(Parent) Top_X_Designation__c(Child) having Lookup relationship.


Erasing extent of one layer using another layer using ArcMap?

I have two layer files which mark the extent of some vegetation types. The base layer includes some areas which does not need to be included. The second layer is solely comprised of unnecessary area coverage.  I need to remove this unnecessary area. I was hoping to subtract the unnecessary area layer from the base layer but am unsure how to do this. I don't have an advanced license so I cannot use the erase tool.  I am using ArcGIS 10.1 for Desktop.


Why can't I comment on my deleted posts?

Why can't I comment on my deleted post if I don't agree with the reasons for deletion?  My answer to  was deleted, but I don't believe syntax checking and grammar/spell checking are the same.


I'm working with a support member for a product, and he insists that I need to be root to install a series of patches, and that sudo won't work; he doesn't provide a reason but seems very firm in his beliefs. Browsing Superuser I can't determine any possible reason for this being the case, and in confirmation, when I run:  sudo -l   I get:  ... User [MY USERNAME] may run the following commands on this host:     (ALL) ALL   Getting access from the Linux/server team to actually be root is not an imediate process as I understand, so I'd prefer to install them myself.  Is there any practical reason whatsoever why sudo would behave differently than root for installing software on a server?


Power series of $f(x)=\frac{1}{1+x+x^2+x^3}$ My try was: $$f(x)=\frac{1}{1+x+x^2+x^3}=\frac{1}{2}\frac{1}{1+x}-\frac{1(x-1)}{2}\frac{1}{1+x^2}$$ Now using the infinite geometric sum I got: $$\frac{1}{2}\sum_{n=0}^\infty(-x)^n-\frac{1}{2}(1-x)\sum_{n=0}^\infty(-x^2)^n=\frac{1}{2}\sum_{n=0}^\infty[(-1)^nx^n-(-1)^nx^{2n+1}+(-1)^nx^{2n}]$$  The problem that I don't know if my moves are valid, and moreover, I don't know how to make it look as Power series.


why declaring a list as [[0]*n]*m is not working in python?

I declared a 2d list R in python as R=[[0]*2]*2 and tried changing the values. But to my surprise the results were wrong. Please see the code. I would like to know why this is happening and how to correct it. Declaring the same array as X=[[0,0],[0,0]]  gives the right result R=[[0]*2]*2 print(R,end="\n\n")     #output 1 for i in range(2):     for j in range(2):         R[i][j]=i+j print(R,end="\n\n")     #output 2   X=[[0,0],[0,0]] print(X,end="\n\n")     #output 3 for i in range(2):     for j in range(2):         X[i][j]=i+j print(X)                #output 4  OUTPUT : [[0, 0], [0, 0]]  [[1, 2], [1, 2]]  [[0, 0], [0, 0]]  [[0, 1], [1, 2]]  [Program finished]


I faced the problem that a chapter is divided into two sub-chapters

I'm typesetting a Ph.D.-thesis and one of the chapters separates into two sub-chapters so I need it to count chapters like that:  1. Chapter one  2a. Chapter two A  2b. Chapter two B  3. Chapter three   Here problem that if we use following comment :  ***********************************************************  \usepackage{etoolbox}% http://ctan.org/pkg/etoolbox  %\usepackage{hyperref}% http://ctan.org/pkg/hyperref  \newcounter{subchapter}\renewcommand{\thesubchapter}{\alph{subchapter}} \makeatletter  % \patchcmd{<cmd>}{<search>}{<replace>}{<success>}{<failure>} \newcommand{\updatechaptercounter}{}  \patchcmd{\@chapter}{\@afterheading}{\updatechaptercounter\@afterheading}{}{}% Regular patch of \@chapter  %\patchcmd{\Hy@org@chapter}{\@afterheading}{\updatechaptercounter\@afterheading}{}{}% Hyperref patch of \@chapter  \makeatother  \providecommand{\theHchapter}{}%  \newcommand{\startsubchapters}{%    \setcounter{subchapter}{0}% Reset sub-chapter numbering    \renewcommand{\thechapter}{\arabic{chapter}\thesubchapter}% Update chapter number display    \renewcommand{\theHchapter}{\arabic{chapter}\thesubchapter}% Update chapter number display (for hyperref)    \renewcommand{\updatechaptercounter}{\addtocounter{chapter}{-1}}% Update chapter number    \let\oldchapter\chapter%   \renewcommand{\chapter}{\stepcounter{subchapter}\oldchapter}% Increment subchapter } \newcommand{\stopsubchapters}{%    \renewcommand{\thechapter}{\arabic{chapter}}% Reset chapter numbering    \renewcommand{\theHchapter}{\arabic{chapter}}% Reset chapter numbering (for hyperref)    \let\chapter\oldchapter% Restore regular \chapter command    \renewcommand{\updatechaptercounter}{}% Clear chapter counter update    \stepcounter{chapter}% Update chapter counter  }  \begin{document}  \tableofcontents  \chapter{chapter one}  \startsubchapters  \chapter{chapter 2 A}  \chapter{chapter 2 B}  \stopsubchapters  \chapter{chapter three}  ********************************************************************************   Respected Teachers/Friends  By using above text in LaTex, we have chapters contents are  1. Chapter one  2a. Chapter two A  3b. Chapter three B  4. chapter 4   Please solve this problem.


Based on the question:      you associate accounts of two or more Stack Exchange network sites, and at least one of those accounts already has 200 or more reputation: +100 on each site (awarded a maximum of one time per site)   The user is only getting Association Bonus when at least one site reaches 200 Reputation.  Does the user get an association bonus if one of his/her accounts had such reputation before but had since been deleted on that site.  Case in Point:    The user used to have an account on travel.SE with a significant reputation but had since been deleted and the only site in SE network where it exists the User has only 137 rep but when an account is recreated on the travel.SE site it gets the 100 rep association bonus.  Is this intentional or an uninteded consequence of having had an association bonus on another site based on previous rep elsewhere?


Below I have shared the APEX code and the Test class code. I receive 100% code coverage, but I cannot grasp certain parts of it. Eg. The system.assert function - is it necessary? How do I know my test class is actually testing a code. I have only created sample records eg. acc1, con1 etc., how do I know if the test class is actually tested. Will I get messages if certain aspects of the test class is run or executed successfully? What should I add/remove here? I am new to APEX, please give me your onion.  Apex code:  global class setExams2Expired implements Schedulable {     global void execute(SchedulableContext ctx) {          List<Certification__c> objects = [         SELECT Id, Expiration_Date__c, Exam_state__c         FROM Certification__c         WHERE Exam_state__c in ('Active')];          for(Certification__c c : objects){             if(c.Expiration_Date__c < date.today()){                 c.Exam_state__c = 'Expired';              }             else if(c.Expiration_Date__c == date.today().addDays(+7)){                 c.Day7ExpiryAlert__c = True;             }         }         update objects;     } }   Test Class:  @isTest public class setExams2ExpiredTest {      @isTest     public static void ifNotExpired() {          Account acc1 = new Account(name='Test Account 1',phone='121212', Global_POD__c ='AP');         insert acc1;         Account acc2 = new Account(name='Test Account 2',phone='343434', Global_POD__c ='AP');         insert acc2;          Contact con1 = new Contact(accountid=acc1.id,lastname='Test Contact 1',email='abcd@gmail.com');         insert con1;         Contact con2 = new Contact(accountid=acc2.id,lastname='Test Contact 2',email='efgh@gmail.com');         insert con2;          Certification__c c = new Certification__c(Contact__c=con1.id, Name = 'abcd', Expiration_Date__c = Date.today().addDays(+2), Exam_state__c = 'Active');         insert c;          Test.startTest();         setExams2Expired ctx = new setExams2Expired();         ctx.execute(null);         System.assertEquals('Active','Active','ifNotExpired doesn\'t work - meaning an exam is either set to expired when it shouldn\'t have been or nothing happenend for a certain record');         Test.stopTest();     }     @isTest     public static void sendEmail(){          Account acc5 = new Account(name='Test Account 5',phone='787878', Global_POD__c ='AP');         insert acc5;         Account acc6 = new Account(name='Test Account 6',phone='898989', Global_POD__c ='AP');         insert acc6;          Contact con5 = new Contact(accountid=acc5.id,lastname='Test Contact 5',email='qrstuv@gmail.com');         insert con5;         Contact con6 = new Contact(accountid=acc6.id,lastname='Test Contact 6',email='wxyz@gmail.com');         insert con6;          Certification__c c = new Certification__c(Contact__c=con5.id, Name = 'efgh', Expiration_Date__c = Date.today().addDays(+7), Exam_state__c = 'Active', Day7ExpiryAlert__c = false);         insert c;          Test.startTest();         setExams2Expired ctx = new setExams2Expired();         ctx.execute(null);         System.assertEquals(false, false,'No alert was sent here');         Test.stopTest();     }  }   UPDATE 15th/03/2019  Test.startTest(); setExams2Expired ctx = new setExams2Expired(); ctx.execute(null); Map<Id, Certification__c> cMap = new Map<Id, Certification__c>([Select id, Exam_state__c, Day7ExpiryAlert__c FROM Certification__c]); System.assertEquals('Active', String.valueOf(cMap.get(c.Exam_state__c))); Test.stopTest();   Working Update  Test.startTest(); setExams2Expired ctx = new setExams2Expired(); ctx.execute(null); Map<Id, Certification__c> cMap = new Map<Id, Certification__c>([Select Exam_state__c FROM Certification__c]); System.assertEquals('Certification__c:{Exam_state__c=Expired, Id='+c.id+'}', String.valueOf(cMap.get(c.Id)), 'setting to expired failed'); Test.stopTest();


What are differences between the terms "time series analysis" and "longitudinal data analysis"

When talking about longitudinal data, we may refer to data collected over time from the same subject / study unit repeatedly, thus there are correlations for the observations within the same subject, i.e., within-subject similarity.  When talking about time-series data, we also refer to the data collected over a series of time and it seems very similar to the longitudinal setting mentioned above.  I'm wondering if someone can provide a clear clarification between these two terms, what is the relationship and what are the differences?


Is the second law of thermodynamics a fundamental law, or does it emerge from other laws?

My question is basically this. Is the second law of thermodynamics a fundamental, basic law of physics, or does it emerge from more fundamental laws?  Let's say I was to write a massive computer simulation of our universe. I model every single sub-atomic particle with all their known behaviours, the fundamental forces of nature as well as (for the sake of this argument) Newtonian mechanics. Now I press the "run" button on my program - will the second law of thermodynamics become "apparent" in this simulation, or would I need to code in special rules for it to work? If I replace Newton's laws with quantum physics, does the answer change in any way?  FWIW, I'm basically a physics pleb. I've never done a course on thermodynamics, and reading about it on the internet confuses me somewhat. So please be gentle and don't assume too much knowledge from my side. :)


I am writing a code to copy a particular portion from a text file into another text file. I want to know what regular expression I should form so that in every RelationRecord the content inside the first curly braces gets copied to a text file. Can somebody please help me.  This is the content of my input file:  [RelationRecord(items=frozenset({'   android.software.live_wallpaper\n', '   location.gps\n'}), support=0.010217983651226158, ordered_statistics=[OrderedStatistic(items_base=frozenset({'   android.software.live_wallpaper\n'}), items_add=frozenset({'   location.gps\n'}), confidence=0.6818181818181819, lift=2.194976076555024), OrderedStatistic(items_base=frozenset({'   location.gps\n'}), items_add=frozenset({'   android.software.live_wallpaper\n'}), confidence=0.03289473684210527, lift=2.1949760765550246)]), RelationRecord(items=frozenset({'   location\n', '   location.gps\n'}), support=0.3106267029972752, ordered_statistics=[OrderedStatistic(items_base=frozenset({'   location\n'}), items_add=frozenset({'   location.gps\n'}), confidence=0.7808219178082192, lift=2.5136986301369864), OrderedStatistic(items_base=frozenset({'   location.gps\n'}), items_add=frozenset({'   location\n'}), confidence=1.0, lift=2.5136986301369864)]),   Code:  import re import sys regex = r"\RelationRecord(items=frozenset({(.*?)\}" myfile = open("CEHRelationRecord.txt", "rt")  test_str = myfile.read()                   myfile.close()   matches = re.finditer(regex, test_str, re.MULTILINE | re.DOTALL)   I expect the following as the output for the given input:  line1:  android.software.live_wallpaper, location.gps line2:  location, location.gps


Given $a > b$, where $a,b ∈ ℝ$, is it always true that $a^2 > b^2$?


Redirect default login page to a custom page

I want to redirect the default WordPress login page to a custom login page. I am adding this code in a plugin:  if (!is_user_logged_in()) {     wp_redirect( wp_login_url( $redirect ) );     exit(); }   But it gives this error:  Fatal error: Call to undefined function is_user_logged_in()   Why is that happening and how can I fix that? Thanks.


Please, explain, how to calculate this limit?  $$\lim_{n \rightarrow \infty} \frac{1}{n} \sum_{k=1}^n \frac{k}{k^2 + 1}$$


The equation for Stirling's Approximation is the following: $$x! = \sqrt{2\pi x} * (\frac{x}{e})^x$$ Writing as a function for y gives us the following: $$y = \sqrt{2\pi x} * (\frac{x}{e})^x$$ Is there a way to solve this equation for x, effectively finding an inverse to this function?


changing filesystem format from xfs to ext4 without losing data

I have a fresh Lucid Lynx (Ubuntu 10.04) running on a laptop. where I defined the filesystems as:   mount point / on ext4 (46 Gb) mount point /home on jfs (63 GB) swap as 3 Gb   I left the machine over night to do some task, without AC power supply. next day in the morning I found it on standby, task completed, but filesystem was not reachable. it gave me I/O error  it seems that there is a problem with jfs and standby.  anyways, to avoid any hassle, I want to move this mount point from jfs format to ext4.  can I do this without losing data and without the need to place the data in a temporary location until transformation is done?  sorry to mention that, but I recall back in the windows days, we would change a FAT16 to FAT32 or a FAT32 to NTFS without having to lose the data. I hope this is available on Linux.  Update The /home filesystem was xfs not jfs, and it seems there is a bug with this filesystem for some reason, I had to re-install the OS twice until I ended up with ext4 for the entire /   However, as a conclusion, it seems that there is no way to make a conversion


Does this fractal have a Hausdorff dimension of 1?

So I'm familiar with the simple methods of calculating the Hausdorff dimension of a fractal, but when I try to apply them for this case I get into trouble. What I mean with the simple method is using the scaling factor and the amount of repetitions to exactly calculate the Hausdorff dimension.  The fractal below is constructed by taking all horizontal line segments, dividing each into three equally long line segments, raise the one in the middle by it's own length and connecting it to its former neighbors with two vertical line segments.    If I decided during my construction steps not to add those vertical lines, it would be clear that the whole fractal would be 1-dimensional. Each vertical line segment is 1-dimensional as well. But if I were to assume that the whole fractal was 1-dimensional, then it would be of infinite length.  There are more cases of fractals I can think of where I run into the same questions. For example a fractal where each point has position (1/2)i on the line interval [0,1] for all i in ℕ. Would this be a 0-dimensional fractal of infinite size?


How to use this unknown symbol on math mode?

I'm not a native english speaker and I don't know the name of the  symbol surrounding G in the picture (to be far I don't know that in my mother tongue).     I need to use it in math mode in a TeX document. Does anyone know how?


Feedback from the community when applying dupe hammer

I try to weld my dupe hammer carefully - honest I do. I'm well aware which tags I can use it in, and I do not agree that .   I do, however, sometimes wonder whether I've used it appropriately. I try to keep an eye on most questions where I've used it to keep an eye out for the OP (or someone else) commenting along the lines of "That's not a duplicate"/"That's not answering my question"/"You're an idiot" and sometimes I've just re-opened the question.  I wish there was some feedback loop in place like there is with questions/answers (and to a lesser extent, comments) where the community can be proactive in telling me I've been an idiot-with-a-dupe-hammer.  I wondered what people might think about some (or all) users being able to provide me with feedback when I dupe hammer. Perhaps something as simple as a "good call"/"bad call" button next to the close-as-dupe message.  There could be some feedback to the closer, such as >3 "bad call" and the user gets an inbox message along the lines of     3 users have indicated that they think your close as duplicate is incorrect.   Is this a useful feature, or pointless?


Running java on online compiler jdoodle.com and having some issues

This is the code I'm practicing for multilevel inheritence, but when I run it the online compiler gives me following errors: public class MyClass {        ^ /grandFather.java:26: error: non-static method talking() cannot be referenced from a static context       son.talking();          ^ /grandFather.java:27: error: non-static method walking() cannot be referenced from a static context       son.walking();          ^ /grandFather.java:28: error: non-static method running() cannot be referenced from a static context       son.running();      This is the code I'm running. It's a practice code for multilevel inheritence in java. I have created 3 class(grandFather, father and son): public class grandFather{         int age;         double height;                  public void talking(){             System.out.println("Grandfather can walk");         }     }          class father extends grandFather{         public void walking(){             System.out.println("Father can walk too");         }     }          class son extends father{         public void running(){             System.out.println("Son can talk, walk and also run");             }              }          public class MyClass {         public static void main(String args[]) {           son kamran = new son();           son.talking();           son.walking();           son.running();         }     }


How does a Faraday Cage Work? Please explain the charges and why it doesn't shock somebody that is in it.


Is my linux machine Ubuntu and what is the meaning of that?

eli5: Is my Linux Mint machine Ubuntu? and what is the difference between ubuntu and say debian? and what other Linux OS's are there out there??   I just say the word Ubuntu and pretend to sound smart in front of my friends muahah!!


I know that "which" or "that" should be used to refer to entities, and "who" to people. However, I have come across "who" being used to refer to companies and agencies in a UK ESL textbook for the second time.  So is the following sentence grammatical in UK English?     An agency or a company who will help you ...


$wpdb->prepare() warning in WordPress 3.5

I am receiving this warning when I try to run a database query:     Warning: Missing argument 2 for wpdb::prepare()   The offending query is:  $result = $wpdb->get_var(     $wpdb->prepare(         "SELECT DISTINCT meta_value FROM $metatable         WHERE meta_key LIKE '%matchme%'         AND meta_value IS NOT NULL         AND meta_value <> ''"      ) );   Is there a way to remove the error by modifying the above query?


I read that the definite article is pronounced differently depending on the word that follows it.  Which is the exact pronunciation of the?


What is the current science on entropic gravity?

In the past couple of years there has been some buzz about , including here on  in Jan 2011.  Many say that there is no way that gravity can be entropic, while others think it is an interesting idea and bears more research.    Has a consensus been reached on entropic gravity?  Is the discussion exactly the same as it was a year ago when the previous question was asked?


How can I move windows between desktops with the keyboard?

Windows+Ctrl+←/→  move the viewport between virtual desktops.  How I can move the active window between virtual desktops using the keyboard, however?


Let $d(n)$ be the number divisors of a natural number $n$. Now let $m$ be a natural number. Find least natural number $n$ such that $d(n)=m$.  Thank you


Possible Duplicate:          Hello  Can anybody suggest me the best editor for ubuntu(9.10) for programming purpose like dreamweaver.and also the command how to install this editor on system.


Inside include/linux/sched.h one of the important task state changing functions is:  #define __set_task_state(tsk, state_value)      \     do { (tsk)->state = (state_value); } while (0) #define set_task_state(tsk, state_value)        \     set_mb((tsk)->state, (state_value))   As you can see there is a do while() structure inside #define __set_task_state(...).   Now my question is, is it just like any other C do-while loop code - or does it have special properties as it is defined inside #define macro?  Thanks


How to repeat a zle widget an arbitrary number of times when the completion menu is open?

I'm using the zsh shell, and I'm trying to install a few key bindings to use keys similar to the ones I would use in a Vim buffer, when a completion menu is open.  So, inside the menuselect keymap I've bound the keys j and k to the zle widgets down-line-or-history and up-line-or-history, by adding the following lines inside ~/.zshrc:  bindkey -M menuselect 'j' down-line-or-history bindkey -M menuselect 'k' up-line-or-history   down-line-or-history and up-line-or-history are described in man zshzle as follows:  down-line-or-history (^N ESC-[B) (j) (ESC-[B)         Move down a line in the buffer, or if already at the bottom line, move to the next event in  the  his‐         tory list.  up-line-or-history (^P ESC-[A) (k) (ESC-[A)         Move up a line in the buffer, or if already at the top line, move to the previous event in the history         list.   Now, I would like to bind C-d and C-u to the same widgets, but repeating them an arbitrary number of times, for example 5.  At first I tried this simple code:  some-widget() {     zle backward-char -n 5 } zle -N some-widget bindkey '^D' some-widget   It binds C-d to the zle widget backward-char, but repeats it 5 times.  Then, I tried to rewrite the code, moving the key binding from the default keymap to the menuselect keymap:  some-widget() {     zle backward-char -n 5 } zle -N some-widget bindkey -M menuselect '^D' some-widget   But it doesn't work as I expected, because when I hit C-d while a completion menu is open, zle seems to execute the default widget bound to C-d, which is delete-char-or-list:  delete-char-or-list (^D) (unbound) (unbound)         Delete the character under the cursor.  If the cursor is at the end of the line, list possible comple‐         tions for the current word.   It exits the current completion menu, and lists possible completions for the current word, instead of moving the cursor backward 5 times.  If it had worked as I expected, I would probably have ended up using this final code:  fast-down-line-or-history() {     zle down-line-or-history -n 5 } zle -N fast-down-line-or-history bindkey -M menuselect '^D' fast-down-line-or-history  fast-up-line-or-history() {     zle up-line-or-history -n 5 } zle -N fast-up-line-or-history bindkey -M menuselect '^U' fast-up-line-or-history   But since it doesn't, I need to find how to repeat a zle widget when a completion menu is open.  How to modify the previous code, so that down-line-or-history is repeated 5 times when hitting C-d while the completion menu is open?


How to show that there does not exist an automorphism of $\Bbb{Q_p}$ except identity. Please help. Is any automorphism of $\Bbb{Q_p}$ already continuous.?


Ubuntu tablet convergence on samsung galaxy note 8.0 gt-5110

Is my samsung galaxy note 8.0 (gt-5110) compatible with the new Ubuntu convergence tablet software, I would like to give it a spin :-)


New OS running on VirtualBox does not run

I installed a new OS in VirtualBox running on Ubuntu. It just gives me this message. I do not know why.  Failed to open a session for the virtual machine Kalilinux.  VT-x is disabled in the BIOS. (VERR_VMX_MSR_VMXON_DISABLED).  Result Code: NS_ERROR_FAILURE (0x80004005) Component: Console Interface: IConsole {8ab7c520-2442-4b66-8d74-4ff1e195d2b6}


How to create a custom Windows 7 ISO file

I have a customised Windows 7 that was written to USB. But I would like to create an ISO file so that i can install this on Virtualbox, as Virtualbox does not boot from USB. However when I create an ISO file using software like imgburn, the ISO is not bootable. How can I make a bootable windows 7 ISO file?  Thanks


Replace will create new object and both side this new will be compared. then why it showing false.   When exactly created new string will be added in string pool?  if("String".replace("g", "G") == "String".replace("g", "G")) {     System.out.println("True");     } else {     System.out.println("False");  }


Invalid Boot Signature after upgrade to 16.04 (dual boot windows 10)

I'm lost not sure what to do here.... I don't know how to configure my secure booting options. I don't which setting to change?


I tried install nvidia driver  The following packages have unmet dependencies:  nvidia-current : Depends: nvidia-304 but it is not going to be installed E: Unable to correct problems, you have held broken packages.  user@host:$ install nvidia-304 Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  nvidia-304 : Depends: lib32gcc1 but it is not going to be installed               Depends: libc6-i386 but it is not going to be installed E: Unable to correct problems, you have held broken packages.   But it have broken dependency. How install nvidia driver properly?


Does crop factor still apply to a vintage film SLR lens?

My friend has a Tamron 24mm lens on his Nikon D5000 and he says that because of its age and the fact it is manual focus, it is still actually a 24mm on his crop sensored camera. Is this right? If so, which 50mm lenses would still be 50mm on the Nikon d5100?


Latex, left margin align equation in a longtable

I've created a longtable in latex, and I've centred it, because it is quite wide, and I don't want my text running off the side. However I have one particularly long equation, which I put in the align block, so it goes down into a new line. However unlike the rest of the equations in column 1, it doesn't start at the same place as the others (which is the left of the margin).   I have tried using the same method as shown here, but that doesn't work.   I'm wondering how I can make it start on at the margin, and also how to remove the [t]  My code and a print screen of my pdf is below:           As you can see from the picture above, column 1, row 5 (with the red text), the equation doesn't start at the same point as the others. And also the [t] is there. Any way to remove it would also be helpful.  \documentclass[10pt,a4paper]{article} \usepackage{array,longtable} \newcolumntype{L}{>{\centering}m{5cm}} \setlength{\extrarowheight}{2.5mm} \usepackage{graphicx} \usepackage{fixltx2e} \usepackage[margin=25mm]{geometry} \usepackage[fleqn]{amsmath} \usepackage{multicol} \usepackage{multirow} \usepackage{float} \usepackage{xcolor}  % all relevant preamble above %  \begin{document} ... ... \begingroup \setlength{\LTleft}{-20cm plus -1fill} \setlength{\LTright}{\LTleft} \renewcommand{\arraystretch}{1.7} \begin{longtable}{ >{$}l<{$} L >{$}l<{$} } \centering .... more similar ....  \overline{X} \cdotp Y \cdotp Z + [(\overline{X} + Y + Z) \cdotp (\overline{X} + \overline{Y} + \overline{Z})]  &  Multiply everything out} &  \begin{aligned}[t] A \cdotp B = \overline{A} + \overline{B}, & \quad A = \overline{X} + Y + Z \\  & \quad B = \overline{X} + \overline{Y} + \overline{Z}  \end{aligned} \\  \begin{aligned}[l] \overline{X} \cdotp Y \cdotp Z + [\textcolor{red}{\overline{X} \cdotp    \overline{X}} + \overline{X} \cdot \overline{Y} + \overline{X} \cdot \overline{Z} + \\                                Y \cdotp \overline{X} + \textcolor{red}{Y  \cdot \overline{Y}} + Y \cdot \overline{Z} +                               Z \cdotp \overline{X} + Z \cdot  \overline{Y} + \textcolor{red}{Z \cdot \overline{Z}}]   \end{aligned}[t] &  Use De Morgans's law [OR to AND] across 3 variables, twice. &  \overline{A+B+C} = \overline{A} \cdotp \overline{B} \cdotp \overline{C} \\  ....  more similar rows  ....  \end{longtable}  \endgroup  ...  ...  \end{document}


How does the government shutdown in the United States affect research projects at universities and national labs?

Has federally funded research at universities and work done at the national labs in the United States been halted due to the government shutdown?  If so, what typically happens then?    Do researchers just stay at home and not show up to work? Or do they show up, and do something similar to what you would see at a labor strike, e.g. megaphones, demonstrations, make demands?


Can anybody please tell me the summation formula for:     $$\sum_{i=1}^NC(k+i-1, i) = ?$$  Where ' k ' is some constant. Here C(x, y) stands for Combinatorics formula e.g. C(12, 6) = 924.


How to automatically fit many bars in barchart using pgfplots?

I am trying to use PGFPlots to display a large amount of bars, and I run into the problem that it cuts off the last of them.  MWE:  \documentclass[crop,tikz]{standalone}  \usepackage{pgfplots} \usepackage{pgfplotstable} \pgfplotsset{compat=1.13}  \begin{document}  \pgfplotstableread{ row label runtime 0 1 5264 1 2 2971 2 4 1866 3 8 1384 4 16 1205 5 32 1144 6 64 1109 7 128 1095 8 256 1108 9 512 1178 10 1024 1335 11 2048 1667 12 4096 1588 13 8192 2843 14 16384 5541 15 32768 10985 16 65536 21873 17 131072 43687 18 262144 87064 19 524288 174119 }\mytable   \begin{tikzpicture}   \begin{axis}[         ylabel={runtime (${\mu}s$)},         xticklabels from table={\mytable}{label},         xtick=data,         ymin=0,         ymax=10000,         ybar,         xticklabel style={           anchor=north west,           align=left,           rotate=-45,           font=\tiny,           inner sep=1pt,         }, ] \addplot+ [] table [y=runtime, x expr=\coordindex] {\mytable}; \end{axis} \end{tikzpicture}  \end{document}   Result:    By adding the following to the axis options, I can make all the bars fit. But I need to manually adjust bar width (and xmax)  xmin=-1, xmax=20, bar width=7pt,     Is there a way to handle many bars in a barplot automatically?


I am doing , and am having a few problems with function notation. I understand the form f(x).  What does the form f: x ↦ y mean? Could you also give one or two examples?  And, if possible, state your source. Thank you.


Why is Windows hibernating when I shut down?

I just shut down Windows and rebooted into Linux. When I try to enter the Windows partition it says . This means that Windows 10 only hibernates instead of shutting down. How do I actually shut down?


The Wikipedia page for  includes the following section:      Every uniform space $V$ becomes a topological space by defining a subset $O$ of $X$ to be open if and only if for every $x$ in $O$ there exists an entourage $V$ such that $V[x]$ is a subset of $O$. In this topology, the neighbourhood filter of a point $x$ is $\{V[x] : V∈Φ\}$. This can be proved with a recursive use of the existence of a "half-size" entourage. Compared to a general topological space the existence of the uniform structure makes possible the comparison of sizes of neighbourhoods: $V[x]$ and $V[y]$ are considered to be of the "same size".   While I have worked through and proved that the topology described is in fact a topology, I'm stuck on how it can be proved that $\{V[x] : V∈Φ\}$ defines the neighbourhood filter of $x$, as I don't understand what the hint there is trying to tell me.   I want to work through the full proof myself, but are there any extra hints to push me in the right direction?


Is it true the following  $ R \subset R^2$ ?  (If yes, I would like to see a rigorous proof.)


How to make a simple division diagram to a base b?

How can I typeset a simple diagram (dividend-quotient-remainder) in a base different to decimal? For example: $120101_{3} \div 102_{3}$


How do I fix an error starting QGIS 1.8.0 on Windows XP?

I note that the installation of qgis completed successfully. However, the log procedure returns this message:     "...... Estrazione: wvhpgn.gsb Estrazione: wyhpgn.gsb Cartella di   destinazione: C:\Programmi\Quantum GIS Lisboa Creato il programma di   disinstallazione: C:\Programmi\Quantum GIS Lisboa\Uninstall-QGIS.exe   Crea cartella: C:\Documents and Settings\All Users\Menu   Avvio\Programmi\Quantum GIS Lisboa   Impossibile accedere al file. Il file Š utilizzato da un altro processo. Running postinstall grass64.bat... Running postinstall   msvcrt.bat... ......"      System parameters: Quantum GIS Lisboa 1.8.0  Microsoft Windows   Professional, Versione 2002, Service Pack 3   The message:      Impossibile accedere al file. Il file Š utilizzato da un altro   processo   translates as      Unable to access the file. The file used by another process   I then get the following error:     "Impossibile trovare il punto di ingresso locale_charset della   procedura nella libreria di collegamento dinamico iconv.dll"   which translates as:     Can not find the entry point of locale_charset procedure in the   dynamic link library iconv.dll


Consumer which call method with object state

I have a class   public final class GGGGG {      private final String str;      public GGGGG(final String str) {         this.str = str;     }      public void showElement(final String test){         System.out.println(this.str+test);     }      public static void main(String[] args) {         GGGGG hello = new GGGGG("hello");         final Test2 test2 = new Test2(hello::showElement);         test2.test();         hello = null;         test2.test();      }      static class Test2{         private final Consumer<String> consumer;          Test2(final Consumer<String> consumer) {             this.consumer = consumer;         }          public void test(){             this.consumer.accept(" world");         }     } }   What I don't understand, in class GGGG I have String str(state)  I create a consumer with method reference to the method showElement And now this consumer has reference to the GGGGG instance. Does consumer keep a reference to the original object or create a new instance, if it the same reference when it will be garbage collected?


Remove "x" number of characters from a string?

In Python: How do I write a function that would remove "x" number of characters from the beginning of a string?    For instance if my string was "gorilla" and I want to be able remove two letters it would then return "rilla".    OR if my string was "table" and I wanted to remove the first three letters it would return "le".    Please help and thank you everyone!


On the structure of "search for weapons and bands of pro-Hussein fighters still holding out"

I came across the following expression:     The primary task of many American troops in Baghdad has been to search for weapons and bands of pro-Hussein fighters still holding out.   This is from a newspaper called The Japan Times, which is published in Japan.  I don't understand the structure of the bold part.   Is "holding out" a gerund? If so, is "pro-Hussein fighters" its semantic subject? Then, how is this sentence different from "weapons and bands which/that pro-Hussein fighters still hold out"?


Multiple values change when changing a single value in a nested list


Looking for a word like "eulogy", but for a person that has not died?

I was thinking of words like the "background" of a person? Their overall qualities summarised into a short form. Eulogy might be a bad example, as it implies praise. A word meaning "a summary of someone's traits and characteristics."


How to set Suricata to log only DNS queries that come from specific IP addresses?

I am new to working with IDS' such as Suricata/Snort. I am currently trying to using Suricata to log DNS requests and responses to malicious domains on my network. On my DNS server I made it so that any request to say, bad.com, would resolve to 127.0.0.1, thus not allowing anybody on my network to access that site.   I have set up Suricata to log all DNS requests, but how do I filter that down and narrow it and tell it to only log requests to 127.0.0.1 and let everything else go unlogged?   I tried to create a rule:  alert dns any any -> 127.0.0.1 any (msg: "BLACKLISTED WEBSITE"; flow:to_client; content:"rrname";sid:2240001;rev:1;)   But that did not work.   What do I need to do to only log DNS requests to certain IPs? I cannot find any information in the documentation or anywhere else on the internet.   Thanks.


So I can use "EWMA" () to update an estimate of the mean as each new measurement is received.    If I know the window size of the smooth($\eta$), the previous estimate($ \bar{x}_t$), and the new measurement ($x_{t+1} $) then I can compute the updated mean with only one new measurement.   $ \bar {x}_{t+1} = \eta \cdot \bar{x}_{t}+(1-\eta)\cdot x_{t+1}$  I have to store the running mean, and know what my window parameter is, but it is fairly simple.  I want a reduced parameter running median.    It doesn't have to be exact.  (Yes, please do not mock me for such a statement - I know it has the potential to open up all sorts of crazy, but it doesn't have to.)    I have ~10k rows.  My typical window size for an informative mean is about 500 elements. I don't want to do a sort of a window for 10,000 times.  My extended use case has hundreds of millions of rows - so that kind of an approach might not scale well.  Is there any way that I can wrap up tail behavior in a statistic, and keep only a subset of the values?  If I had an ecdf, then I could keep unique values. On average i would only have to update part of the stored values.  If I "disimproved" the granularity of the measurements then I could move toward fixed bin locations, and operate primarily in bin memberships.  If I did piecewise linear interpolation on the CDF then I could update those parameters over time, and that could reduce the overhead, right?  I would have to make sure that I had enough segments, and that things stayed well behaved, numerically speaking.  Questions:   Are there "textbook" approaches for windowed moving medians?  What are they? Is there a variation on the Theil-Sen estimator that could be useful for this?   Please provide thoughts or references.


Is there is a way that program is not asking for Admin password?

When I am trying to start "cmd.exe" as a Administrator, it won't ask for password and I can execute commands.  Below code is working good, but it is asking Admin password.  Is there a way that it should resolve automatically and run under local admin account?   string subCommand = @"dir";         string subCommandArgs = @"c:\";         string subCommandFinal = @"cmd /K \""" + subCommand.Replace(@"\", @"\\") + " " + subCommandArgs.Replace(@"\", @"\\") + @"\""";         ProcessStartInfo procStartInfo = new ProcessStartInfo("runas.exe");         procStartInfo.UseShellExecute = true;         procStartInfo.CreateNoWindow = true;         string finalArgs = @"/env /user:Administrator """ + subCommandFinal + @"""";         procStartInfo.Arguments = finalArgs;         using (System.Diagnostics.Process proc = new System.Diagnostics.Process())         {             proc.StartInfo = procStartInfo;             proc.Start();         }


Photoshop: How to paint black and white image to purple and yellow

I need to make my black and white image purple and yellow. Turn all black colors to purple, all white to yellow and all grey shades to proportion of purple and yellow the same as black and white in original image. Is there a way I can do this in photoshop?


How can I link two Google accounts to one Stack Exchange account?

I have one SO login that is linked to a Google Apps Account. The thing is... I have a second Google Apps account and I would like to add it to My Logins but nothing I have tried has worked.  I've tried editing the email address on my login profile. It now shows the second Google App email address but when I click on the Google logo to login I still have to log in to Google with the first account for the fullOfGAS username to appear when I log in to SO.


I have multiple points and I need to create polygons that consist specific amount of points.   How could i do this?


How to show that the variance estimator of a gaussian is biased?

The sample variance of $m$ samples from a gaussian is  $$ \hat{\sigma}^2_m=\frac{1}{m}\sum_{i=1}^m(x^{(i)}-\hat{\mu}_m)^2$$ How do i show that the sample variance $\hat{\sigma}_m^2$ is biased ? I.e  $$E[\hat{\sigma}_m^2] = E[\frac{1}{m}\sum_{i=1}^m(x^{(i)} - \hat{\mu}_m)^2] = \frac{m-1}{m}\sigma^2$$


Using "will have" with the past participle

I came across the following example from the textbook Advanced Grammar in Use by Martin Hewings.  To say that we think a past situation actually happened, we use will have + past participle:  As it was cloudy, few people will have seen last night’s lunar eclipse.   Why isn't the past simple or past perfect used in the aforementioned example?  As it was cloudy, few people saw last night’s lunar eclipse.


If a given # is $70$% of $X$. How do you determine what $X$ is?

Given I have the number $50,000$ which is $70$% of $X$. How do I calculate what $X$ is without guessing.  Thanks


Gold casket: the portrait isn't in the silver casket. Silver: the portrait isn't in this casket. Lead: the portrait is in this casket.  At least one of the statements was true and at least one of them was false. Which casket contains the portrait.  If you say any one of the three statements is true, you will end up with all of them being true.


Create blinking text with echo and escape characters

I have learned about formatting options used in shell scripting, which go like this:  \033[37:40mAnyText\033[0m   Now I want to echo some text like this:  echo -e "SomeText \033[5;31;47mMoreText\033[0m"   The integer 5 is for blinking. The other formatting works, but not the blinking -- why?


Going to install Ubuntu 10.10 on new intel x25M 80GB SSD. It will be fresh install. I have been googling for past few days and getting overwhelming articles/blogs/Q&As. One particularly very useful being:     But with so many suggestions and differences of opinions (on different links) this simple OS install process seems to be daunting task to me and I really want to stick with Ubuntu (although have used for very short period of time).  Can someone help me by answering few questions (yes, they are repeated because I couldn't comprehend the answers elsewhere)   Which file system (ext2/3/4 or something else)? (consider SSD life) Can it be changed after installation? Should I partition the disk? (as we do in traditional HDD) for now, no plan of dual booting. Only Ubuntu will live on scarce space of 80GB SSD. I have 2 GB RAM, should i still allocate swap space (if I don't allocate swap space, can I still hibernate the machine)? will swap space impact SSD life? Should I consider putting additional 1GB RAM to avoid swap space? What is partition aligning? Is it needed to be done before installing the Ubuntu OS or can be done later?   Intended usage - heavy browsing, programming, regular video/music and some other non-CPU/RAM-intensive programs. Will keep big files in an external hard drive.  laptop config - 3yr old Vaio, Core2 Duo, 2GB RAM  More references:        (resizing/creating does not seem a simple process after look this)


How to install software or upgrade from an old unsupported release?

Recently I have installed an older version of Ubuntu on my old machine. Whenever I try to install any software, I get an error saying it couldn't be found:  $ sudo apt-get install vlc Reading package lists... Done                Building dependency tree        Reading state information... Done     E: Couldn't find package vlc


Why is the unity feedback system used? This block diagram is for a 2 DOF ball balancing using a PID controller.


How does Luke learn to fight with a lightsaber?

In the movies, Luke's only lightsaber training that we see is a brief time aboard the Millennium Falcon when Luke squares off against the remote droid. They never get to actual dueling practice before Obi-Wan is killed.  Yoda does not appear to teach Luke any swordfighting techniques, but Luke has at least a rudimentary skill level when facing Vader in The Empire Strikes Back.  In Return of the Jedi, Luke's skill has increased considerably - enough to put up a good fight against Vader, an accomplished fighter.  In Disney canon, where did Luke learn how to fight with a lightsaber?


Does any connected metrizable space with more than one element have uncountably many open sets, each generating a connected subspace?

Moderator's note: I've copied the title of the post from a more recently posted version of this question by the OP. The text below is from the original question: I am not sure whether the motivations still applied, hence I left it untouched.   It is well known that any connected metrizable space with more than two points is uncountable. And any connected metrizable space has infinitely many open spheres; as each such sphere is connected, there are infinitely many connected subspaces. But must it be the case that any connected metrizable space has uncountably many connected subspaces?


Why does one player on a volleyball team wear a different shirt?

In Volleyball one player wears a different color shirt in the team while others wear the same color.  What is the reason for it?


Don't remove privileges for rep given to bounties

I have observed at least one user who takes a very "ascetic" approach to rep: He awards bounties to questions he finds interesting, meritorious of more attention, and to reward/highlight exceptional answers.  Often to the point that his rep falls back to just double digits.  He does this on multiple sites where he is an outstanding contributor.  Just auditing his bounty activity on two sites: he has given away over 6,000 rep points, and I can find no indication of any nefarious or unintended consequences of the bounties.  I.e., he is using the bounty system as designed.  He is also revealing what I would consider to be a flaw: He is an Established User, but, due to his generous awarding of bounties, he is frequently toiling under the restrictions applied to inexperienced users.  E.g., it's silly to have his edits held up for review.  Though the implementation to change this might not be considered a priority, do people at least agree in principle that users should not lose privileges for spending their rep on bounties?  (.  Arguments for the status quo of losing privileges point out that there should be a cost to awarding bounties.  I would point out that loss of rep is a cost, and it is the right cost: You can't award more bounties than you earn in rep.)


should we include or exclude a variable in a logistic regression based on the description below?

should we include or exclude a variable in a logit regr. model which will only obtain values if a certain event takes place otherwise will show N/A? this variable tells whether or not a product will be bought based on calls made by the company. the variable tells: number of days that passed by after the client was last contacted from a previous campaign. the values (-1) are for users who


How can I avoid displacements in exported JPEGS from QGIS 2.2?

I observed a small but annoying problem for a long time now. I have to design maps/plans of survey areas for work including maps where a satellite image is printed under a vector-layer showing the outlines of the single survey fields. For the satellite images I use the build in Google Satellite layer from the OpenLayers plugin.   In QGIS everything looks OK, but when I export a JPEG or PDF-File from QGIS there is often a significant displacement of the Satellite Layer.  I tried to solve this by setting different Spatial reference systems or using Bing Satellite instead of Google, but it seems to have nothing to do with that. I found out, that it sometimes helps to set the plan to another scale before exporting. But this is often to big or doesn't help.  Anyone ever had this problem and/or know how to get rid of it?


Find a formula relating $\operatorname{arcsin}(x)$ and $\operatorname{arccos}(x)$

From the formula $\sin\left(\frac{π}{2}−x\right)=\cos x$, find a formula relating $\operatorname{arcsin}(x)$ and $\operatorname{arccos}(x)$.   I have figured out that the domain of $x$ is $[-1;1]$, but I have no idea how to do this. I've tried letting $y=\cos x$ and the only result I've got is $$\operatorname{arccos}(y)+\operatorname{arcsin}(y)=\frac{π}{2}$$ I need a full answer.


How to output an index while iterating over an array in python

I am iterating over an array in python:  for g in [ games[0:4] ]:     g.output()   Can I also initialise and increment an index in that for loop and pass it to g.output()?  such that g.output(2) results in:  Game 2 - ... stuff relating to the object `g` here.


when two matrices are similar in $M_n( \Bbb{C} )$?

Let $M_n( \Bbb{C} )$ be set of all $n \times n$ matrices over $$\{\Bbb{C}\setminus \Bbb{R} \}$$ then for $A,B \in M_n( \Bbb{C} )$ are similar iff minimal polynomial and characteristic polynomial of $A,B$ are same? Is this statement true! It is obvious that converse is true but I am not sure about the other way around! I know that above statement is not true if matrix is over $\Bbb{R}$ can we generalise it over $\Bbb{C}$ ? I am asking specifically for matrix with pure complex entries!


If $\gcd (a,b)=1$, and $\gcd(a,c)=1$, then $\gcd (a,bc)=1$ Help proving this? I'm really confused how to go about it..


As the title may give you a hint, I'll be in a Rome for the first time.   The challenge now - is there a website where I can buy tickets (with a guide included) for Vatican museums?


As the title says! I am looking for an onomatopoeia for coughing, as in:     "[sound]" he coughed violently, as if his lungs were ...etc   Alternative suggestions are also gladly accepted :_ Thanks!


How can I know the status of my UK Visa before receiving my Passport

I have applied for UK visitor Visa two weeks ago and I have received this email:     Your UK visa application has been processed. Please contact TLS at pos.tlscontact.com/kbp_en/index.php/contact if you have not been contacted within the next 2 days regarding return of your documents   Is there anyway to know the decision without having to wait until I receive my passport back?


is this font called Computer Modern, is there a way to find out which font I am using on overleaf?

this code $\mathcal{Y}$ generates this symbol by default on overleaf    is this font called Computer Modern, designed by Donald Knuth?  is there a way to find out which font I am using on overleaf?


Solve the equation $x^n=a$ in a finite field

Good evening! I'm studing something about finite fields and I didn't find anything that can answer my question.  I have a finite field $\mathbf{F}_q$ and the equation to solve is $x^n=a$. Which are the condition to resolve this equation? For which values of $q, n, a$ there exist a solution?  I will be very happy if anyone can answer this question, possibly with a reference of a book (or an article) that explai this with more details.  Thank in advance to everyone who can answer this one, I really need to understand this.


Getting into a decent Ph.D. program with 3.3 GPA

Long story short, I was caught up in the party life in my early 20's and my GPA was a 2.5 when I came back to school. Since returning to school I have done a 180 with straight A's for two of my last 3 semesters. From my current school, my GPA is a 3.5. I have yet to take the GRE but I know I will have strong letters of recommendations from professors and one offered to turn my research design for our final into an independent study with me the summer before I apply for Ph.D. programs. My question is will GPA reflect too poorly on me with a high GRE, strong letters of recommendation and research experience?


When I press shift+f8 or f8 on boot time windows 10, I can't find safe boot mode. How to boot in safe mode windows 10?


Stop elements from being pulled apart one page

I have a very long LaTeX document with many tables, figures, etc.  When I have a long table on the following site (which means it doesn't fit on the current site) the elements (paragraphs, tables, figures...) on the current site are pulled apart, so that the first element is at the top of the page and last one at the bottom,with large white spaces inbetween each element.   Is it possible to change this, so that in such a case the elements would be as normal at the top with just aone large white space at the bottom of the page?


Testing whether two regression coefficients are significantly different (in R ideally)

If this is a duplicate question, please point to the right way, but the similar questions I've found here haven't been sufficiently similar. Suppose I estimate the model $$Y=\alpha + \beta X + u$$  and find that $\beta>0$. However, it turns out that $X=X_1+X_2$, and I suspect $\partial Y/\partial X_1 \ne \partial Y / \partial X_2$, and in particular, that $\partial Y/\partial X_1 > \partial Y / \partial X_2$. So I estimate the model $$Y=\alpha + \beta_1 X_1 + \beta_2 X_2 +u$$and find significant evidence for $\beta_1,\beta_2>0$. How can I then test whether $\beta_1> \beta_2$? I considered running another regression $$Y=\alpha +\gamma(X_1 - X_2) + u$$ And testing whether $\gamma>0$. Is this the best way?  Also, I need to generalize the answer to many variables, i.e. suppose we have $$Y=\alpha + \beta^1 X^1 + \beta ^2 X^2 + \dots + \beta^nX^n + u$$ where for each $j=1,\dots,n$, $X^j=X_1^j+X_2^j$, and I would like to test for each $j$ whether $\partial Y/\partial X_1^j \ne \partial Y / \partial X_2^j$.  By the way, I am primarily working in R.


Show for prime numbers of the form $p=4n+1$,  $x=(2n)!$ solves the congruence $x^2\equiv-1 \pmod p$. $p$ is therefore not a gaussian prime.

I need to show that for prime numbers of the form $p=4n+1$, $x=(2n)!$ solves the congruence $x^2 \equiv-1\pmod p$. I then need to show this implies p isn't a gaussian prime.   I have started to solve this using Wilson's theorem that a number $z$ is prime iff $(z-1)!\equiv-1\pmod z$. Therefore the endpoint of my proof should be that $(p-1)!\equiv-1\pmod p$.  As $p$ is of the form $p=4n+1$, I only need to prove that $4n!$ is congruent to $-1$ modulo $p$.   Here is my working so far: Starting with the congruence $x^2 \equiv -1\pmod p$:    $$\eqalign{x^2 = -1\pmod p&\implies   x^2 + 1 = kp \implies (x-i)(x+i) = kp\cr &\implies ((2n)!-i)((2n!)+i))=kp \implies 4n!- 1 =kp\cr}$$   This is where I start to run out of any ideas that seem to get me anywhere. Any tips would be greatly appreciated!


Book in which girl's father marries a woman with two children who are all immortal

I remember reading a book about a teenage girl's father marrying a woman with a son and daughter. The teenage girl soon finds out that something was weird about this new family. And what's fishy is that the woman and her children never age. They were immortal. The son and daughter try to kill the girl in a secret lake during the book sometime. And the book ends with her living with the daughter as she ages and dies like a normal human. Thank you


No Lebesgue-measurable subset such that $\lambda(I\cap A) = \frac{1}{2} \lambda(I) \forall I$

Prove that there exists no Lebesgue-measurable subset $A$ of the real numbers such that for every interval $I$ the Lebesgue measure of $A\cap I$ is half the length of $I$.  My attempt:  assuming there exist such $A$ that works with some interval $I$, I wanted to show that there exists some interval in $I\setminus A$ but I couldn't show it.


See this question    The entire content of the question, copied verbatim, is      Java code to read the end page of PDF file and add a Digital signature at the end line of PDF using i Text.   Within less than 1 minute of being posted it already had one upvote.  I see this quite often, really horrible questions with no redeeming content getting one or two upvotes. Usually, the questions are from very-low-rep users (i.e. <1000) but this happens for higher rep as well.  Is there a random new-user upvote "feature" to encourage new users?  Or, is there some other mechanism or unintended incentive that encourages this?


It seems as if no one has asked this here before, unless I don't know how to search.  The Gamma function is $$ \Gamma(\alpha)=\int_0^\infty x^{\alpha-1} e^{-x}\,dx. $$ Why is $$ \Gamma\left(\frac{1}{2}\right)=\sqrt{\pi}\text{ ?} $$ (I'll post my own answer, but I know there are many ways to show this, so post your own!)


Derivation of Conservation of Energy from Newton's Second Law

Given Newtons's Second Law: $$ \frac {d}{dt} (m \boldsymbol{\dot r}) = \mathbf F $$ How is it possible to derive the conservation of energy equation with a constant mass?  That is how can you derive $ \mathbf F = - \nabla V(\mathbf r) $ where $V(\mathbf r)$ is shown to be the potential energy when the force is conservative?  Attempted Proof:  Let $KE = T = \frac {1}{2} m\boldsymbol{\dot r} \cdot \boldsymbol{\dot r} $  or $$\frac{dT}{dt} = \frac{1}{2}m[\boldsymbol{\dot r} \cdot \frac {d \boldsymbol{\dot r}}{dt} + \boldsymbol{\dot r} \cdot \frac {d \boldsymbol{\dot r}}{dt}]  = m \boldsymbol {\dot r} \cdot \frac {d \boldsymbol{\dot r}}{dt}$$  and $\nabla V = \frac {\partial V} {\partial{\mathbf r}} $  Also, a conservative force says $\frac{dE}{dt} = 0$  Newton's Second Law could also be written as: $$m\boldsymbol{\dot r} \cdot \frac{d\boldsymbol{\dot r}}{dt} = \mathbf F \cdot \boldsymbol{\dot r}$$    My question is how is $ \mathbf F = - \nabla V(\mathbf r) $ introduced to Newton's second law properly and then integrated (? maybe) to obtain the energy?   Because I can easily prove that $ \mathbf F = - \nabla V(\mathbf r) $ if $E = T + V(\mathbf r)$ but I am trying to conclude that $V(\mathbf r)$ is the potential energy, not assume it


Why did the Order bother to guard the Prophecy?

(And please, nobody say "Cause Dumbedore asked them to")  We know one of the tasks of the Order after its re-creation was to keep safe a weapon Voldemort was after.     “What’s he after apart from followers?” Harry asked swiftly.   He thought he saw Sirius and Lupin exchange the most fleeting of looks before Sirius said, “Stuff he can only get by stealth.”   When Harry continued to look puzzled, Sirius said, “Like a weapon. Something he didn’t have last time.”   (Order of the Phoenix, Chapter 5, The Order of the Phoenix)   Sturgis Podmore was Imperiused while patrolling around the door behind which it was kept, and Arthur Weasley was attacked there by Nagini (or Voldemort in Nagini).     “Your father has been injured in the course of his work for the Order of the Phoenix,” said Dumbledore.   [...]   “The Ministry wouldn’t want everyone to know a dirty great serpent got —”   “Arthur!” said Mrs. Weasley warningly.   “— got — er — me,” Mr. Weasley said hastily,   [...]   “You were guarding it, weren’t you?” said George quietly. “The weapon? The thing You-Know-Who’s after?”   “George, be quiet!” snapped Mrs. Weasley.   “Anyway,” said Mr. Weasley in a raised voice...   (Order of the Phoenix, Chapter 22, St Mungo's Hospital)   -     “Sturgis Podmore,” said Hermione, breathlessly. “Arrested for trying to get through a door. Lucius Malfoy got him too. I bet he did it the day you saw him there, Harry. Sturgis had Moody’s Invisibility Cloak, right? So what if he was standing guard by the door, invisible, and Malfoy heard him move, or guessed he was there, or just did the Imperius Curse on the off chance that a guard was there? So when Sturgis next had an opportunity — probably when it was his turn on guard duty again — he tried to get into the department to steal the weapon for Voldemort"   (Order of the Phoenix, Chapter 26, Seen And Unforeseen)   We also learn later that  about Voldemort and Harry.  Voldemort was after it, because he thought its end would tell him how to destroy Harry.     And so, since his return to his body, and particularly since your extraordinary escape from him last year, he has been determined to hear that prophecy in its entirety. This is the weapon he has been seeking so assiduously   since his return: the knowledge of how to destroy you.   (Order of the Phoenix, Chapter 37, The Lost Prophecy)   But let's look at the content of the Prophecy, and what part he already knows of:     “THE ONE WITH THE POWER TO VANQUISH THE DARK LORD APPROACHES... BORN TO THOSE WHO HAVE THRICE DEFIED HIM, BORN   AS THE SEVENTH MONTH DIES... AND THE DARK LORD WILL MARK HIM AS HIS EQUAL, BUT HE WILL HAVE POWER THE DARK LORD KNOWS   NOT... AND EITHER MUST DIE AT THE HAND OF THE OTHER FOR NEITHER CAN LIVE WHILE THE OTHER SURVIVES... THE ONE WITH THE   POWER TO VANQUISH THE DARK LORD WILL BE BORN AS THE SEVENTH MONTH DIES...”   (Order of the Phoenix, Chapter 37, The Lost Prophecy)   -     “He heard only the first part, the part foretelling the birth of a boy in July to parents who had thrice defied Voldemort."   (Order of the Phoenix, Chapter 37, The Lost Prophecy)   The bold parts are already known to Voldemort... and the rest of the prophecy does not really gives him valuable information:   Mark him as his equal: OK, that's already done. He'll have a power the Dark Lord knows not: Yep, that's love. But since Voldemort does not know of it, he won't be able to understand this sentence. He will imagine another power, but that won't help him (and he probably already guessed this while planning to kill baby Harry). Either must die at the hand of the other...: Alright, so Voldemort should go and kill Harry then! Oh, but he kind of already wanted to anyway, didn't he?   Was preventing Voldemort from hearing the end of the Prophecy worth all the trouble and the risks (one member of the Order lost for 6 months to Azkaban, another heavily wounded and happy not to be dead...)? Why did they bother to do so?


To praise a text by saying it has nothing excessive

A friend of mine is a journalist, and I want to praise his new article by saying that it's not "a lot of words with a little sense", but the opposite. The ideas are solid, the wordings are precise, there are no excessive words, and there are no words or phrases that are trying to look smarter than they are. It's like an idealized Spartan warrior.


Is cascade triggered by putting a creature into play?

If  is on the field when I cast a 5/5, and I use Wild Pair to put  into play, does Enlisted Wurm's cascade trigger?  Wild Pair: Whenever a creature enters the battlefield, if you cast it from your hand, you may search your library for a creature card with the same total power and toughness and put it onto the battlefield. If you do, shuffle your library. Enlisted Wurm: Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)


Prove that an open interval $(a,b)$ considered as a subspace of a real line is homeomorphic to the real line.

I understand that in $(\Bbb R ,d)$, any open interval $(a,b)$ is topologically equivalent to $\Bbb R$. But here the topology is unspecific, so I have no idea how to proceed.  Could anybody help me? Thanks!


How would pressing backspace 28 times break Grub2

I just came across this article about how pressing backspace 28 times on the grub screen.  Since most mainstream media just says this happens, I've been unable to find anything that explains how it could possibly happen.  Does anybody know why pressing backspace 28 times would break Grub2? Is it a memory thing?


I often use Stack Exchange sites on my smartphone. The mobile version works great, but when I end up on a page which is not found (like a deleted question), it redirects me to the full version of site.  Can you please re-design that page to adjust on a small screen?


At night, we hear weak and far sounds approximately clear, while during the day we cannot.  My high school physics teacher was saying that “this is because of interference of sound waves. During the day, there are a lot of sounds and they cancel each other due to interference. But, during the night, there are few sounds and they can reach to our ears without canceling each other”.  But, this doesn’t make sense because even in silent days (according to my personal experience), we don’t hear those sounds that night are heard clearly.  As I am not familiar with waves so much, I will appreciate if someone clear me by simple explanation.


Madrid Airport changing terminals, do I need a Schengen visa?

I am an Indian citizen. I am flying from Toronto to New Delhi. I have two transits: one at Lisbon airport and the second one at Madrid airport.  While the Consulate of Portugal has assured me that I do not need an airport transit visa during my 2 hours stay in Lisbon airport, I did not get a definitive answer from the consulate of Spain in Toronto.   At Madrid airport, I need to make a transfer from Terminal 2 to Terminal 1.   Does anyone here know whether I need to pass through immigration while making this transition in Madrid and if so, do I need a Schengen visa for that?


Why "--" is not permitted in Lightning Component's comments in markup? How to toggle markup with class names like "uiInput--input"?

In a Lightning Component, I have the following markup which I have to comment in and out for testing purpose  <force:inputField value="{!v.account.Name}" class="form-control uiInput--input input" />   now when I try to comment it out like this  <!--<force:inputField value="{!v.account.Name}" class="form-control uiInput--input input" />-->   the API tells me     markup://c:elfL1:6,81: ParseError at [row,col]:[7,81] Message: The   string "--" is not permitted within comments.   Since I didn't figure out that fancy class name uiInput--input (Salesforce did so...) it would be nice to be able to toggle that om/off OR avoid to use class names like this...


Which method should I choose to install GNOME?

Note : My question itself answers how to install GNOME  I want to install Gnome desktop in my 64-bit Ubuntu 14.04 I just googled and I found two ways to install GNOME. I also read other answers on Ask Ubuntu and googled but can't find what is difference between this both!  1st method to install is :  sudo apt-get install gnome-shell sudo apt-get install ubuntu-gnome-desktop   2nd method  sudo add-apt-repository ppa:gnome3-team/gnome3-staging sudo add-apt-repository ppa:gnome3-team/gnome3 sudo apt-get update sudo apt-get dist-upgrade   If I try installing using first way, it shows following errors:  The following packages have unmet dependencies: gnome-shell : Depends: gnome-settings-daemon (>= 3.4.0) but it is not                        going to be installed               Recommends: gnome-control-center but it is not going to be installed ubuntu-gnome-desktop : Depends: gdm but it is not going to be installed                        Depends: gnome-control-center but it is not going to be installed                        Depends: gnome-session but it is not going to be installed                        Depends: gnome-settings-daemon but it is not going to be installed                        Depends: gnome-shell-extensions but it is not going to be installed E: Unable to correct problems, you have held broken packages.   And If I try installing 2nd way, after entering sudo apt-get dist-upgrade command it tells me that 299Mb space will be used and I just aborted it pressing n.  What is right way to install Gnome desktop in Ubuntu 14.04.  And one more thing, as there are two methods available to install Gnome, which is best? Up to I know using 1st method I can switch to Gnome desktop by logging out from Unity and choosing GNOME.   What would happen if I install Gnome using 2nd method? Will it remove Unity from my computer or I will be able to use both Unity by logging out?


If I have a post with delete votes, I delete it myself, and then I undelete it, what will happen?

It is a hyphotetical idea. I have no intent to do this with any of my posts.    Thus, consider the following events:   I make a post. It is voted down. It gets delete votes, but not enough to be deleted. I delete it myself (consider if it is possible). Then I undelete it. Because it was my own post deleted by me, I think also this is possible.   Is it possible?  What will happen to the delete votes what the question got in (3)?


Ukrainian Citizen traveling from Canada to Frankfurt to Warsaw to Lviv. Schengen visa needed?

I am a Ukrainian citizen living in Canada. I am taking a vacation to Ukraine and I am looking at flight options.  Do I need a Schengen visa if I make two stops in the EU, even if I do not leave the airport? It is extremely hard for me to get a Schengen visa as I would need to travel to Vancouver to get this, which is an hour flight or 12 hour drive!!  My flight options are as follows; Edmonton (Canada) - Frankfurt (Germany) - Warsaw (Poland) - Lviv (Ukraine)  OR  Edmonton (Canada) - Calgary (Canada) - London (UK)  - Warsaw (Poland) - Lviv (Ukraine)  I was told by a friend that she had problems when trying to transit between two Schengen countries, without a Schengen visa, even if she was not walking out of either airport, with Ukraine as her final destination.  UK is not schengen, does this mean that I can transit between Canada-UK-Schengen-Ukraine without problem?


why does modulo not work with decimals in python?

In PYTHON(3.4.3): How come in the code below x is 3.5... and y is 100. Shouldn't x be 0.  weight = 356 weight2 = 3.56 x = weight%weight2 y = weight/weight2 print(x) print(y)   But in this code x does = 0 as expected:  weight = 35600 weight2 = 356 x = weight%weight2 y = weight/weight2 print(x) print(y)   If you have any explanation please answer and give a workaround if you have one!! :)


Problem Show that $f(t)=t^5-5t+1$ has no repeated roots. My initial idea I write $f$ in terms of linear factors $(t-\alpha_1)...(t-\alpha_5)$ where all the $\alpha_i$ make up the five roots of $f$. I’d like to show that each possibility of there even existing multiplicities in the factorization leads to a contradiction. The following statements are all that is necessary to prove the original question without loss of generality and after renumbering the $\alpha_i$. The first case would be that $f(t)=(t-\alpha_1)^2(t-\alpha_2)(t-\alpha_3)(t-\alpha_4)$. The second would be that $f(t)=(t-\alpha_1)^2(t-\alpha_2)^2(t-\alpha_3).$ The third case would be that $f(t)=(t-\alpha_1)^3(t-\alpha_2)(t-\alpha_3)$, and so on proving the rest of these possibilities until they are all exhausted out. My question Obviously, this is time consuming and there’s likely a better solution. I would like any suggestions on how to solve the problem quicker without this exhaustive method. Any thoughts would be appreciated. Remark I tagged irreducible polynomials and gcd/lcm because I am not sure if any suggestions would have to do with them, yet I still suspect that they would.


Is it possible to upgrade windows 7 Pro (Volume License) to Enterprise without rebuilding

is it possible to upgrade windows 7 pro (volume license) to enterprise without rebuilding the whole pc.  i would use anytime upgrade but it's not available on the volume license edition.


What is the value of $\lim_{n\to \infty} \sum_{j=n}^{4n} {4n \choose j}\bigl(\frac{1}{4}\bigr)^{j} \bigl(\frac{3}{4}\bigr)^{4n-j}$?

Find the value of the limit  $$\lim_{n\to \infty} \sum_{j=n}^{4n} {4n \choose j}\left(\dfrac{1}{4}\right)^{j} \left(\dfrac{3}{4}\right)^{4n-j}$$  First we take the limit of the summation from $0$ to $\infty$ then subtract the sum from $0$ to $n-1$. The value of the first sum is $1$. I can't determine the second sum with limit. How we find it?


I like to use the idiom 'phone it in' in the sense described by :     To fulfill a responsibility with a minimum effort rather than the appropriate level of effort.    For example: 'He used to try his best at this task but at the moment he's really phoning it in.'  However, friends and colleagues do not seem to recognize the idiom. Is there an equivalent idiom that might be more likely to be understood?


Is there much benefit in memorising proofs outside of an exam setting?

This is a question I have been thinking about for a while, which seems especially important as I hope to transition from undergraduate to graduate study in the next year, where studying for an exam becomes less important and studying for actual learning becomes more important.   I have always been required as part of my degree to learn proofs. Seemingly, basically, just memorising them line-by-line - there might be other methods for answering "prove [random proposition in the lecture notes]" questions, but memorisation is most effective and effectively forced by a tight time limit.   I always thought there had to be a good reason these kind of questions were put - in fact, apparently required by guidelines to be put - in the examinations. Therefore, even when teaching myself maths, I put in the effort to memorise as many proofs of theorems and propositions as I could. This especially seemed useful for maintaining understanding over long periods of time.   Now, I wonder if this was all just a bit of a waste of time. I have read many people commenting here that doing problems is far more useful - "you learn maths by doing it".   Am I wrong? Is there value in memorising proofs (after having read and understood them, not as opposed to skipping them entirely)? Or is this just a waste of time? What about when reading research papers?


Proving that the maximum of two convex functions is also convex

Here's a homework question I'm struggling with:  Let $f,g$ two convex functions. Prove that $h(x)=\max\{f(x),g(x)\}$ is also convex  I don't know where to begin. The only thing I had in mind was was to try proving that if a function is convex on two sets $A$ and $B$, it is also convex on their union. That does not seem right though, for example, if I glue together $f(x)=x^2, g(x)=\frac{x^2}{1000}$ where $f$ is defined on $[0,1]$ and $g$ on $(1,2]$. Anyway, that was the only thing I thought about. Any better ideas? thanks!


Series of books with a flood and a creature masquerading as a woman

I don't remember the author or title, but the story is set down south. One day there was a flood and a new woman showed up. She got involved with the matriarch's son. Turns out she is a creature that came with the flood and her enemies start to disappear. I hope this may sound familiar to someone. I read it in the late 80's, the cover had an eye on it with the town flooded in the background. There were at least 6 books in the series. Thanks


When I asked the driver/ to come with me to the temple/ he had been reluctant./ No error.   I think instead of 'had been', there should be 'was'. Even the answer key points that the error is in the 'he had been reluctant' part. But I am not sure why exactly is 'had been' wrong.  If we replace the first part with 'when I had asked the driver', would that make 'had been' in the third part correct?


How to remove the FBI Ransomware malware?

A computer in our household got hit by the FBI "ransomware" virus.   Here are details of what happened (Win 7 Home Premium):   Family member was in a forum. AVG Free (which was up-to-date) warned of an attack. An Adobe Flash install popped up. Windows UAC popped up confirming Flash install. We answered No/Cancelled to each Flash install prompt. But it (and UAC dialog) wouldn't go away. Both would pop back up after clicking No or Cancel. We restarted the computer (Start -> Restart) without ever answering Yes to the Flash install. -On reboot the FBI Ransomware screen displayed and we were sunk.   We tried booting into Safe Mode but the ransom screen STILL appeared. Yes, even in Safe Mode.  Was hoping there'd be a list of instructions with quick steps for removing this virus. Thought I found it with  but that question was marked as a duplicate with redirect to  which contains loads of general techniques for malware removal --many very involved and impractical if you're trying to get back up FAST. (If that's possible.)  Is there any set of instructions for what to do to remove this specific ransomware infection, including not being able to boot to Safe Mode?


Let $R$ be a commutative ring with unity and $M$ an $R$-module.   If $M\oplus R^m\cong R^n$ for some integers $m,n \geq 1$ then must $M$ be finitely generated and free?   Can somebody help me with this? Regards.


Does deliberately falling cost movement?

If you willingly fall on your turn does it cost movement?  As a DM I'm thinking about how to handle things such as creatures who are immune to being prone, diving into the water from a height, or a flying creature diving off a cliff and taking a fall before taking flight. There are many circumstances where you can fall without taking damage or being knocked prone afterward, and I'm not sure how to determine movement following the dive.  For example, my character walks up to a ledge above a 10 foot drop to the ground below. After taking 5 feet of movement to step off the ledge, I allow myself to fall. When I hit the ground have I used 15 feet of movement or just 5?


Create custom keyboard shortcut in Ubuntu 17.10 / 18.04

In previous versions of Ubuntu I could create custom keyboard shortcut to run terminal commands, with something like gksudo reboot for example, and then assign that to something like win+r.  I can't find that option in Ubuntu 17.10 or Ubuntu 18.04 daily build.  Am I missing something?


How did C-3PO and R2-D2 get on Leia's ship?

Okay, so those of you who have seen it already, you know that the ending scene appears to take place just moments before Vader boards Leia's ship at the beginning of A New Hope.  But when the report came to the senator that rebels are on Scarif and Admiral Raddus is already on his way there, C-3PO and R2-D2 are seen on Yavin 4.  So did the last scene take place just before the beginning of A New Hope, and if so, how in the heck did the droids get on that ship?


I've seen a lot of people in this situation, but every time the variables differ and so does the solution for it.  I think I have everything installed correctly. I have Nvidia GeForce 540M with Bumblebee drivers installed.  What happens is, every two times when Ubuntu starts it tells me it is running in low-end graphics mode. I say OK and it crashes at the next window. I just restart and it starts normally.  I've made:  lspci -nn | grep '\[030[02]\]:   and the answer was:  00:02.0 VGA compatible controller [0300]: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0116] (rev 09) 01:00.0 3D controller [0302]: NVIDIA Corporation GF108 [GeForce GT 540M] [10de:0df4] (rev ff)


Make "[feedback site]" a proper link in digest emails

The  link is Stack Exchange digest emails is rendered incorrectly. I expected a proper link, as above, and got markdown: Questions? Comments? Let us know on our [feedback site](https://meta.stackexchange.com).


Where can I find good literature for beginners?

I am trying to find some database tutorials,books and similar, since I have started this course in college, and received some material, but it is really hard to manage through all the info on the net. I searched through the questions on the site but didn't find any. Thankfull for all your input.