Currently with the achievements dropdown for rep changes you see the site icon, then rep change, then a link, but when earning a badge there is a gap where the rep is for reputation achievements.  I think the empty space (where the mouse cursor is in the pic below) should have the badge icon there, possibly linking to the badge in question.

I would like to suggest an update to Stack Exchange sites regarding the notification that is shown when a user earns a new badge.  Currently, all notifications are shown in the same color, like this:    This notification is great, but if you get more than one badge, it can be difficult to differentiate between those and "normal" messages.  I would like to propose this:  For each new badge a user earns, the background color should change based on the badge type. So for a gold badge, the background would be gold, etc...  Here's a quick look on how it would look like:    Now, if you earn more than one, it will look like this:    I think that this way it becomes much easier to distinguish all newly earned badges.


On math.stackexchange, I did a search for exception user:25554 (25554 being my user number), looking for a particular post.  The app did not find it.  But when I search on the web site with a web browser, the web site search did find it; it's .          In fact the Android app found only five posts, but  produces sixty posts.   suggest that one-word searches are converted to tag searches. That does not appear to be the case here.  A search for throws exception user:25554 on the Android app finds nothing, but , including the one I was looking for.  My device is a Samsung GT-I8190N (“Galaxy S3 mini”) running Android 4.1.2.  I am using the SE Android App Version 1.0.26.

I have a Samsung Galaxy S3. Android version 4.3  I downloaded the official StackExchange app today. I am not able to view post related to android tag from my profile. I tried refreshing also  Snap     Edit:  However i am able to see one post for the relevant from the drop down list    Edit 2:  I tried what Steven V suggested. However it's the same.    I tried for a different user its the same.


I am looking for the easiest (elementary) proof that $\mathbb R$ is infinite dimensional as a $\mathbb Q$-vector space, without using cardinality. It should be understandable at highschool level.  So I guess the question could be reformulated as: what is the easiest infinite family of reals that can be showed to be independent ? So far square roots of primes seems a good candidate, but the proof is still a little intricate, is it the easiest possible ?  The goal of this is to show students that we can prove the result by different ways, and see that understanding cardinals is useful. But I still want the students to be able to understand the other proof.

It would seem that one way of proving this would be to show the existence of non-algebraic numbers. Is there a simpler way to show this?


I was using Math.random()*(max-min))+min but this is all exclusive. How can I make it inclusive and what is the method behind figuring this out? I tried Math.random()*(max-min))+min until I realized that it was all exclusive. I'm trying to figure out the logic behind how to make this with the min inclusive. I also tried Math. random() * (max - min + 1) + min but this makes the upper inclusive. Simply stated: How can I use Math.random() generate numbers from a minimum (inclusive) to a maximum (exclusive)?

How do I generate a random int value in a specific range? I have tried the following, but those do not work: Attempt 1: randomNum = minimum + (int)(Math.random() * maximum);  Bug: randomNum can be bigger than maximum. Attempt 2: Random rn = new Random(); int n = maximum - minimum + 1; int i = rn.nextInt() % n; randomNum =  minimum + i;  Bug: randomNum can be smaller than minimum.


I'm looking for a solution to Hartshorne Exercise 1.1.1(c), that uses no, or as little as possible, coordinates transformations, and using only material from section 1 of Hartshorne.     The question is to show that if $f\in\mathbb{C}[x,y]$ is irreducible quadratic, then $\mathbb{C}[x,y]/(f)$ is isomorphic to $\mathbb{C}[x]$ or $\mathbb{C}[x,x^{-1}]$.   Here is the outline I have in mind:  If $\mathbb{C}\subsetneq A(W)^\times$, then let $u\in A(W)^\times\setminus \mathbb{C}$ be such that it has no root in $A(W)$ (i.e. there is no element $v$ s.t. $u=v^k$ for some $k>1$). Take the map $\mathbb{C}[x,x^{-1}]\to A(W),x\mapsto u$. This map is an isomorphism, the problem is how to prove it.   It is injective since the kernel is prime, and thus if nonzero corresponds to a maximal ideal in $\mathbb{C}[x,x^{-1}]$, contradicting the assumption that $u\not\in\mathbb{C}$.   I'm having trouble showing that this map must be surjective without some annoying explicit computations. I think we could start by noting that $\mathrm{Frac}(A(W))$ is an algebraic extension of $\mathrm{Frac}(\mathbb{C}[x,x^{-1}])$. Then we assume that the degree of the extension is greater then $1$. Then this means that $u$ (any representative in $\mathbb{C}[x,y]$) is at least quadratic. But $V(u)\cap W=\emptyset$, since $u$ is a unit in $A(W)$. Now I do not really how to proceed without resorting to doing some explicit computation anyway. So does someone know how to finish this in an elegant way?  In case $\mathbb{C}= A(W)^\times$ we would want to take an irreducible nonunit $u$, and construct the map $\mathbb{C}[x]\to u$. Again it is easy to see that this map is injective. In this case the map is surjective, since it having degree higher than $1$ contradicts the irreducibility of $u$.

An algebraic set (not necessairly a variety) $X \subseteq \mathbb{A}^2$ defined by a polynomial of degree $2$ is called a conic.  The problem is:     Show that any irreducible conic is isomorphic either to $Z(y-x^2)$ or to $Z(xy-1)$ after an affine change of coordinates in $\mathbb{A}^2$.   However, with this definition of conic, I only can conclude that if the polynomial is irreducible, then the conic is irreducible (because $f$ irreducible $\Rightarrow Z(f)=X$ is irreducible)     What can I do to prove that if a conic is irreducible, then the polynomial that defines the conic is irreducible?   And for the main problem, how can I do the affine change of coordinates?  Thanks


The big bang model is first discussed when the people witnesses that almost every galaxies are speeding away from each other suggesting that at one point in time or more accurately at $t=0$ everything including space-time have to be congregated together. Is there any truth to this model?

Ok so the universe is in constant expansion, that has been proven, right? And that means that it was smaller in the past.. But what's the smallest size we can be sure the universe has ever had?  I just want to know what's the oldest thing we are sure about.


I've seen other questions about merging objects, usually involving deleting faces from both of them and connecting them together. But that's not what I want. I just want to be able to control many objects together, using scale, movement, etc, as if it was only one object.  Does anyone know how to do this? It seems like it should be easy but I haven't found a good explanation yet..

I'm creating side skirts for a truck and I am duplicating the frames I want. The problem is it's making the duplicated object into another object. How do I put it into the same one?


The majority of questions I see as being closed for being "off-topic" specifically say (when voting to close) the question is suited for some other Stack Exchange site. Makes sense, but why close it rather than move it?  Example(s):     Not sure if this has been mentioned before (as everything I searched refereed to a post about  "Why was my question closed as off-topic?").

I posted a question which was closed as off-topic and it seems like it could fit on another site in the network. How can I go about moving it there?   What is migration? When can a question be migrated, and who can migrate it? When should I consider migration, and when is it inappropriate? What causes a migration to be blocked and what happens after? What causes a migration to be rejected and what happens after? Anything else I should know about migration?


If I have a thread running in the background, is there any way it can retrieve from Python's raw_input what has been typed so far? Example: User is sitting at prompt and typing away. I would like to receive what has been typed so far at the 5 second mark, 10 second mark, etc.   Relatedly, is there any type of KeyboardEvent indicating that typing is going on?  Additionally, is there any way to modify raw_input's buffer? Clear the buffer from a different thread?  For threading I'm using the 'signal' module.

How can I poll the keyboard from a console python app?  Specifically, I would like to do something akin to this in the midst of a lot of other I/O activities (socket selects, serial port access, etc.):     while 1:       # doing amazing pythonic embedded stuff       # ...        # periodically do a non-blocking check to see if       # we are being told to do something else       x = keyboard.read(1000, timeout = 0)        if len(x):           # ok, some key got pressed           # do something   What is the correct pythonic way to do this on Windows?  Also, portability to Linux wouldn't be bad, though it's not required.


while I inserting records in a table it throws :  Arithmetic overflow error converting expression to data type int.  Code:  create table JEmp ( J_Id int Identity, J_Name varchar(100), J_Contact int, J_City varchar(100), primary key(J_Id) )  insert into JEmp(J_Name, J_Contact, J_City)  values ('David Warner', 9821766418, 'New York')

If I run this code:  select 99999 * 9999   result = 999890001  If I run this code:  select 9999923 * 99999999   result:     Msg 8115, Level 16, State 2, Line 1   Arithmetic overflow error converting expression to data type int.   And If I run the following code:  select 922337299987987689745893 * 999999994564   result = 922337294974162127011191918541325652  Why am I getting this arithmetic overflow error within a specific range?


Here is a capture of the current rendering I get :  I am obliged to set a "\," after the GC$_{\text{ph}}$ and WL to have a little spacing after these symbol to not interfer with classical text, that is to say : \newcommand{\GCp}{GC$_{\text{ph}}$\,} \newcommand{\WL}{WL\,}  and the Latex source : Here after a triplot showing the 2D joint distribution with individually the \GCp and \WL probes and their simple combination.  As you can see, this is not symmetric and even I put "\," on each side in \newcommand, this is not pretty. I am on overleaf. If someone could tell me how to fix this ?

I have a definition:  \newcommand{\arnold}{Arnold Schwarzenegger}   When I refer to it by:  \arnold is a   it is rendered as:   Arnold Schwarzeneggeris a    In order to have a space in front of "is" I would need to write  \arnold\ is a   Is there some other shorter way?


The difference between mode 1 and mode 2 start thread? Method 1: I use the same Runnable object to start multiple threads Method 2: I use different Runnable objects to start multiple threads package com.hbase.a;  public class MyThreadB implements Runnable {     private  int tik = 100;      public void run() {        //do ...     }        public static void main(String[] args) {         // method-1          MyThreadB myThreadB = new MyThreadB();         new Thread(myThreadB).start();         new Thread(myThreadB).start();         new Thread(myThreadB).start();         new Thread(myThreadB).start();                 // method -2          new Thread(new MyThreadB()).start();         new Thread(new MyThreadB()).start();         new Thread(new MyThreadB()).start();         new Thread(new MyThreadB()).start();      } }

From what time I've spent with threads in Java, I've found these two ways to write threads:  With implements Runnable:  public class MyRunnable implements Runnable {     public void run() {         //Code     } } //Started with a "new Thread(new MyRunnable()).start()" call   Or, with extends Thread:  public class MyThread extends Thread {     public MyThread() {         super("MyThread");     }     public void run() {         //Code     } } //Started with a "new MyThread().start()" call   Is there any significant difference in these two blocks of code ?


All single quotes in code samples are displayed as backticks and the copy-pasted code can't be compiled without fixing the quotation. Is it possible to prevent this?  for example:  \documentclass{beamer} \usepackage{listings} \begin{document}  \lstset{language=Python} \begin{frame}[fragile]{Code} \begin{lstlisting} print 'hi'  \end{lstlisting} \end{frame} \end{document}   Compiled with latexmk -pdf file.tex, which creates a log starting like: This is pdfTeX, Version 3.1415926-2.5-1.40.14 (TeX Live 2013).  Output:

Basically I want  \mint{python}|'banana'|   to produce straight single quotes, rather than the curly ones it normally produces (in pdflatex).


I am trying to get this equation:    But this is the result:    this is my code:  \begin{equation*} adds =\frac{p}{(1-p)} =\frac{ la probabilitée de présence d'un caractéréstique}{la probabilitée de l'absence de caractéréstique} \end{equation*}

This is best explained by example. Suppose I have the following:  \[     \begin{align*}     C_3 \rightarrow 6 automorphisms\\     C_4 \rightarrow 8 automorphisms\\     C_5 \rightarrow 10 automorphisms     \end{align*} \]   How can I get the word "automorphisms" to display as if it were not enclosed by the brackets?


I'm having trouble attempting this question. In a group of $n$ people, what is the probability that at least $3$ have the same birthday?   I started off by saying Pr(At least $3$) $= 1 -$ (Pr(no $3$) + Pr($2$ share a birthday)).   However, how would i calculate that exactly $2$ people have the same birthday, or is this wrong? Any suggestions on how to continue?

Question: whats the probability that at least 3 out of a group of n people have the same birthday.  I am confused as to where to start. I know that it would be complementary probability, but even then I dont know exactly.  Would it be;  P(at least 3 have the same bday) = 1 - (|all 3 have different| + (2 have the same|)? Any directions and suggestions?


As a mathematics student interested in theoretical physics, I found it very hard to study about anomalies in QFT in standard physics texts. They concentrate on particular examples (like chiral anomaly), however, I want to know about general properties of anomalies in a Quantum Field Theory. Do you know of any books, lecture notes, or any other references for a proper general properties of anomalies for a mathematics student?

I am a first year PhD student in theoretical physics with a background in QFT (up until relativistic fields, path integrals and gauge theories and anomalies) and some algebraic topology but my understanding of anomalies is weak and I am looking for references for discrete anomalies or anomalies in general. Any textbooks/papers that could be useful are appreciated.


Thanks for trying to help me. I have to have my ISO set to 200 and use manual settings for an assignment, but all my images are coming out black (or almost black). I have tried in my living room and in a train (early morning but the train is quite lit).  What are the best camera settings to fix this and shoot the most versatile range of photos? Like in ordinary light? Thank you!

I was taking photos a few days ago, and I had it set to Manual. After about four photos, the rest started coming out black. I could see through my eyepiece clearly, and it took the photo normally, but when I reviewed it they were all black.


I am looking at this tutorial () and I want to make the curve into a watertight model for 3D printing. Is this possible?

Is is possible to remove the curves and only have the mesh of a tree that was created with the saplings add-on?   I'd like to apply a decimate modifier to have a few low-poly trees, but this doesn't work because of the curves. I get this message: "Cannot apply constructive modifiers on a curve."


I'm having issue retrieving data from firebase.im trying to get the  information related to this node "0506326662" and the sub-node "Location". I also created class named UserInformation that will hold the data as an object but for some reason i'm getting an error and i have no clue where it comes from and why.   databaseReference.child("Users").child(numbeT).                 child("Location").addValueEventListener(new ValueEventListener() {             @Override             public void onDataChange(@NonNull DataSnapshot dataSnapshot) {                  for(DataSnapshot ds:dataSnapshot.getChildren())                 {                      uInfo=new UserInformation();                      uInfo.setLastOnline(ds.child(numbeT).getValue(UserInformation.class).getLastOnline());                     uInfo.setLag(ds.child(numbeT).getValue(UserInformation.class).getLag());                     uInfo.setLat(ds.child(numbeT).getValue(UserInformation.class).getLat());                  }     ERROR LogCat(firebase)  2019-03-23 17:58:52.187 4657-4657/com.alrubaye.mytracker E/AndroidRuntime: FATAL EXCEPTION: main     Process: com.alrubaye.mytracker, PID: 4657     java.lang.NullPointerException: Attempt to invoke virtual method 'java.text.SimpleDateFormat com.alrubaye.mytracker.UserInformation.getLastOnline()' on a null object reference         at com.alrubaye.mytracker.MyServie$1.onDataChange(MyServie.java:79)         at com.google.firebase.database.core.ValueEventRegistration.fireEvent(com.google.firebase:firebase-database@@16.1.0:75)         at com.google.firebase.database.core.view.DataEvent.fire(com.google.firebase:firebase-database@@16.1.0:63)         at com.google.firebase.database.core.view.EventRaiser$1.run(com.google.firebase:firebase-database@@16.1.0:55)         at android.os.Handler.handleCallback(Handler.java:873)         at android.os.Handler.dispatchMessage(Handler.java:99)         at android.os.Looper.loop(Looper.java:193)         at android.app.ActivityThread.main(ActivityThread.java:6669)         at java.lang.reflect.Method.invoke(Native Method)         at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)   UserInformation class:  package com.alrubaye.mytracker;  import java.text.SimpleDateFormat;  public class UserInformation {     private SimpleDateFormat lastOnline;     private String lag;     private String lat;      public UserInformation() {      }      public SimpleDateFormat getLastOnline() {         return lastOnline;     }      public void setLastOnline(SimpleDateFormat lastOnline) {         this.lastOnline = lastOnline;     }      public String getLag() {         return lag;     }      public void setLag(String lag) {         this.lag = lag;     }      public String getLat() {         return lat;     }      public void setLat(String lat) {         this.lat = lat;     } }

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


Good evening everyone, I'm asking for a proof of "Rolle's theorem generalization". The thesis is as follows:  Let be $a \in \mathbb{R}$ and $f:[a,\infty) \longrightarrow \mathbb{R}$ a continuous function such that $\lim_{{x\to \infty}} {f(x)} = f(a)$. Prove that if the derivative exists in $(a,\infty)$ then $\exists$  $x_0>a$ such that $f'(x)=0$.  I tried to prove that but I wasn't able to do it, so if you can help me I'll appreciate it a lot. Thank you for your time.

$f(0)=0$ and $\lim_{x \to \infty}f(x)=0$ and $f$ is differentiable in $\mathbb{R}$  How can I show there's $x_0$ such that $f'(x_0)=0$.  I know it's true since the values of f(x) for large enough x are close to 0 as much as I want. So, that means that the same value would have to appear at least twice, and then it can be concluded. However, I don't know how to show it formally.


I just bought 2 , but when I check them on CPU-Z, I see they are operating at 1200MHz.  Could someone help to bring them back to 2400MHz?  Thanks

I have an Acer Veriton l670 mini PM. My machine has:   E8400 3 GHz dual core CPU 2x2, 4 GB DDR2 800 MHz RAM dual channel (Kingston acr256x64d2s800c6) 320 GB hard disk 7200 rpm   While this is not a very bad PC, I can't play Civilization V with the lowest options (it lags in game). I decided to check my PC with CPU-Z software. I am confused that it shows my memory running at half speed. Is there any jumper to change the speed?


Im struggling with how to do things.  My goal is that when in on my jumphost type ssh router1, then it will ssh to the router, and at the same time run an expect script to fill in my password from a password file (which ofcource is readonly to me) preferably it should send it encrypter so that it cant be picked up by anyone.  I have managet to get an expect script to work, but i dont want to have a gazillion expect scripts in my folder (for the amount of routers we have).  Im thinking it could be done using alias commands? I already have alias commands setup so that if i type router1 it will automatically ssh to that particular router.  (i got a message that this was a duplicate, but i have been unsucessfull in finding the duplicate question, so I am gonna try to explain further: Lets say that we, in my company have 100 routers. for now i have made alias'es so when i type router1 in my prompt, it will do ssh router1. I want to try to extend that functionality and shave off a few precious ms of time, by filling in the password automatically.  So in other words im looking for a way to combine alias with an expect script (and possibly a bash script if needed) and i am shockingly bad at any scripting  Hope someone can help :)

I tried writing a shell script which can do automatic login into a ssh server using password which is mentioned in the script. I have written the following code:  set timeout 30 /usr/bin/ssh -p 8484 root@172.31.72.103 expect  {    "root@172.31.72.103's password"     {       send "password\r"     } }   This code is not running properly, still it is asking for the password. Can somebody please help me in solving this


Let $ \{a_n\}\in \mathbb{C}$. Prove that if $\sum |a_n|^2$ converges than $\sum \frac{a_n}{n}$ converges.  Note that this problem is taken from the first chapter on series of a calculus book, so it should be solvable with very basic tools (e.g. the only convergence test introduced was the comparison test and nothing about absolute convergence is assumed).  I have tried a few thing but nothing worked. Could you give me a hint on how to approach the problem?

Problem:      Suppose that for every $n\in\mathbb{N}$, $a_n\in\mathbb{R}$ and $a_n\ge 0$. Given that   $$\sum_0^\infty a_n$$   converges, show that    $$\sum_1^\infty \frac{\sqrt{a_n}}{n} $$   converges.   Source: Rudin, Principles of Mathematical Analysis, Chapter 3, Exercise 7.


In a tutorial, I'm prompted "If you are running Squeeze, follow these instructions..." and "If you are running Wheezy, follow these other instructions..."  When I run uname, I get the following information:  Linux dragon-debian 3.2.0-4-686-pae #1 SMP Debian 3.2.63-2+deb7u2 i686 GNU/Linux   Is that information enough to know if I'm using Squeeze or Wheezy, or do I get that from somewhere else?

I'm working on a simple bash script that should be able to run on Ubuntu and CentOS distributions (support for Debian and Fedora/RHEL would be a plus) and I need to know the name and version of the distribution the script is running (in order to trigger specific actions, for instance the creation of repositories). So far what I've got is this:  OS=$(awk '/DISTRIB_ID=/' /etc/*-release | sed 's/DISTRIB_ID=//' | tr '[:upper:]' '[:lower:]') ARCH=$(uname -m | sed 's/x86_//;s/i[3-6]86/32/') VERSION=$(awk '/DISTRIB_RELEASE=/' /etc/*-release | sed 's/DISTRIB_RELEASE=//' | sed 's/[.]0/./')  if [ -z "$OS" ]; then     OS=$(awk '{print $1}' /etc/*-release | tr '[:upper:]' '[:lower:]') fi  if [ -z "$VERSION" ]; then     VERSION=$(awk '{print $3}' /etc/*-release) fi  echo $OS echo $ARCH echo $VERSION   This seems to work, returning ubuntu or centos (I haven't tried others) as the release name. However, I have a feeling that there must be an easier, more reliable way of finding this out -- is that true?  It doesn't work for RedHat. /etc/redhat-release contains : Redhat Linux Entreprise release 5.5  So, the version is not the third word, you'd better use :  OS_MAJOR_VERSION=`sed -rn 's/.*([0-9])\.[0-9].*/\1/p' /etc/redhat-release` OS_MINOR_VERSION=`sed -rn 's/.*[0-9].([0-9]).*/\1/p' /etc/redhat-release` echo "RedHat/CentOS $OS_MAJOR_VERSION.$OS_MINOR_VERSION"


I want to know how to connect to Cassandra using Perl, and insert, select, update etc.  I tried this  my $dbh = DBI->connect(     "dbi:Cassandra:host=localhost;keyspace=nomkeyspace",     "root",     '',     { RaiseError => 1 } );  my $rows = $dbh->selectall_arratref( "SELECT id, nom" );  for my $row ( @$rows ) {     print( "ok" ); }  $dbh->do( "insert into resultat (ip, nom) values (?,?)" );  $dbh->disconnect;   but it's give me this error     Can't locate DBD/Cassandra.pm in @INC (you may need to install the DBD::Cassandra module)   thanks

I get this error:  Can't locate Foo.pm in @INC  Is there an easier way to install it than downloading, untarring, making, etc?


I'm a college fresh man on my winter vacation and I'm previewing the part in my next term's Mathematical Analysis that deals with the infinite series. I have therefore learned some tricks for deciding if a series converges or not. Those tricks are quite useful, but only sometimes. When confronted with some very tricky series (perhaps in a rather simple form) they just don't work out very smoothly or even cannot work at all. So my notion is that our tricks for testing convergence are actually quite weak, and that there may well be a good many series whose convergence or divergence hasn't been revealed yet. And thus I'm asking for such an example. In addition, I want to briefly mention something interesting (my own experience): Before taking an elementary calculus course at the age of 14, I feel very strongly, by my intuition, that $\displaystyle\sum_{i=1}^{\infty}\frac1i$ must be something convergent. I "tested" it on my calculator, which told me that when $i$ turns large (in fact, no more than 50 I believe) the rate at which the sum increases has already been incredibly slow. So even without any proof I thought to myself that it would be a joke if such a thing should diverge. Of course, I was wrong, and I later learned many ways to prove I was wrong. Still, it is no surprise that someone who lacks this part of knowledge and trusts  their "mathematical intuition" will, you can almost guarantee, make the same mistake as I did. I simply get this feeling that when we are confronted with a brand new series which none of our tricks can work out (and intuition or technology is of no good help), it is just grossly difficult, or even not quite possible for us to decide its convergence or otherwise. So I firmly believe there are still some tricky ones that still bother us nowadays.

Are there any infinite series about which we don't know whether it converges or not? Or are the convergence tests exhaustive, so that in the hands of a competent mathematician any series will eventually be shown to converge or diverge? EDIT: People were kind enough to point out that without imposing restrictions on the terms it's trivial to find such "open problem" sequences. So, to clarify, what I had in mind were sequences whose terms are composed of "simple" functions, the kind you would find in an introductory calculus text: exponential, factorial, etc.


Is the colon used in the following sentence correct? If so, would it be better to replace it with a semicolon or a period?     As CPUs get faster and faster, it is important that the performance of the memory system keeps pace: otherwise, the speed of the overall system will be compromised by the memory system bottleneck.

I've seen a few questions on this site relating to semi-colons, which I believe I correctly understand, but what I'm not as clear about is colons.  For example:     The man ate the apple; it tasted good.   Is this not correctly also written as:     The man ate the apple: it tasted good.   In this case, what is the difference between the two sentences?


I want to get a cookie from http request header not set http request header using javascript. I've found many answer about getting http response header. But none of it mentioned about a request header. Anyway can I get it?

I want to capture the HTTP request header fields, primarily the Referer and User-Agent, within my client-side JavaScript.  How may I access them?    Google Analytics manages to get the data via JavaScript that they have you embed in you pages, so it is definitely possible.     Related:


Hey guys i'm learning how to code shell scripts and tried to do a simple html page. My script looks like this:  #!/bin/bash  # sysinfo_page - A script to produce an html file  cat <<- _EOF_ <html>     <head>         <title>         The title of your page         </title>     </head>      <body>         Your page content goes here.     </body> </html> _EOF_   And it's saved in my $HOME/bin, but doesn't quite work. Path is okay because i have other simple script working from there (Hello World). This one creates the html file but empty, and i don't know why. When i use command:  sysinfo_page > sysinfo_page.html   First it tells me i have no permission so i have to use sudo for this, and then tells me   sudo: sysinfo_page: command not found   But the sysinfo_page.html is created empty anyway.

Whenever I open a .sh file, it opens it in gedit instead of the terminal. I can't find any option similar to Right Click → Open With → Other Application... → Terminal.  How do I open this file in the terminal?


I just did a search for "find out how much memory a python program takes" on Google and came up with two hits that contain the same content:       Interestingly, the comanswer.com site was higher ranked. I guess they do a better job at search engine optimization (SEO).

of Stack Overflow, all content posted on Stack Exchange sites by their users (i.e. you wonderful people) has been provided to the whole universe under . For my fellow non-lawyers, that license basically means:   Anyone can use any Stack Exchange posts at any time without having to ask for permission Making money off of the copied content is permitted You don't even have to copy stuff from here verbatim; you can just use it as a starting point and make whatever edits you want There are just two rules you have to follow:   You have to provide . Simple links to the original post and author info are just fine. You have to  and allow other people to use your content, as long as they follow these very same rules. How meta!    (If you ever forget any of that, and want to refresh your memory, the license info is linked to in the footer of every page.)  There are, in fact, a lot of people who republish varying amounts of our content for assorted reasons. Unfortunately, there are some Stack Content Republishers Attributing Poorly and/or Excelling at Ranking (SCRAPERs, for short).  In this context, "attributing poorly" means any use that doesn't follow our attribution rules or make any other reasonable attempt at give credit. This can get pretty egregious; I've seen SCRAPERs that not only don't link back to SE originals, but also use fake author info and post dates to make it harder to find originals. By "excelling at ranking," I'm referring to copycat sites that end up higher in Google results than the original SE sites do for the same content. That's not necessarily wrong, but in some cases, it indicates inappropriate SEO hackery.  So, the question is: what can you do if you spot a SCRAPER?


I am trying to find an answer to this problem  "Show that the sets $\mathbb Q$ of rational numbers and $A = \{x \in\mathbb Q | 0 \le x \le 1\}$ have the same cardinality"  So, I know we would have to find a bijection from $\mathbb Q$ to $A$. I was thinking of this one :  $f(x) = \begin{cases} \frac{x}{x+1},  & \text{if $x$ > - 1} \\[2ex] 1, & \text{if $x$ = -1} \\[2ex] ?, & \text{if $x$ < -1} \\ \end{cases} $  which I guess it would be well defined (since $x < x+1, \frac{x}{x+1} < 1$) and injective ( $$\frac{x}{x+1} = \frac{x'}{x'+1}  => xx' + x = x'x + x' => x =x'$$). But now I can't find how to define the rationals under -1 to make f surjective !  I tried also to find a bijection from $\mathbb N\times\mathbb N$ to $A$ (we already saw in class that $|\mathbb N\times \mathbb N| = |\mathbb N| = |\mathbb Q|$)  So far, the closest answer on Internet I could find to my question was on this topic :  , but I can't make sense of it, so I am doing a new topic !  Thank you very much for your help

While reading about cardinality, I've seen a few examples of bijections from the open unit interval $(0,1)$ to $\mathbb{R}$, one example being the function defined by $f(x)=\tan\pi(2x-1)/2$. Another geometric example is found by bending the unit interval into a semicircle with center $P$, and mapping a point to its projection from $P$ onto the real line.  My question is, is there a bijection between the open unit interval $(0,1)$ and $\mathbb{R}$ such that rationals are mapped to rationals and irrationals are mapped to irrationals?  I played around with mappings similar to $x\mapsto 1/x$, but found that this never really had the right range, and using google didn't yield any examples, at least none which I could find. Any examples would be most appreciated, thanks!


In Harry Potter 7, Harry visits his parent's graves. He also sees his old house, with a sign:  On this spot, on this night of 31 October 1981, Lily and James Potter lost their lives. Their son, Harry, remains the only wizard ever to have survived the Killing Curse. This house, invisible to Muggles, has been left in its ruined state as a monument to the Potters and as a reminder of the violence that tore apart their family.  The sign says the house is invisible to Muggles, therefore wizards can see it, such as the person who put up the sign, the people who scribbled on the sign, Hagrid who came to the site after the Potter's death, and Hermione who was beside Harry. That doesn't make sense: We know Wormtail is the secret keeper and Wormtail isn't dead, and for all I know he didn't tell the whole wizarding world where the house was, so how can all the wizards see it?

When Harry and Hermione visit Godric's Hollow, Harry wonders something I find rather silly:     ... they passed more cottages: any one of them might have been the one in which James and Lily had once lived...He was not  even sure whether he would be able to see the cottage at all; he did not know what happened when the subjects of a Fidelius Charm died.   Harry was a living subject of the charm, and arguably the primary one.  As such, the charm still should be in effect And if anyone at all could see the house it would be him.  Then they actually find the house:     He could see it; the Fidelius Charm must have died with James and Lily.   I think that's a poor conclusion for the aforementioned reasons. But Hermione could see it, along with the wizards who put up and signed the sign.  The secret-keeper was still alive, so the secret didn't leak out via secondary keepers.  So why did the charm break?


I am trying to connect to my single board computer terminal, which has OpenWRT Linux. in order to do that, I connect the board serial pin (UART) to my pc and access to the terminal using Putty. I need to modify some network configuration file.     1- I only have vi or vim editor on my Linux.   2- I cannot install any other editor using package manager because I do not have access to the internet and also my USB port.   there are some tutorials on the net that introduced some commands but they are not working for putty in serial mode.   for example, vi can be opened in 2 modes, command mode and edit mode I can go to edit mode by typing i and exit from this mode by Esc key. but I cannot save the modifications.

I did find this answer here:   However none of the commands listed worked for me. Exit, cntrl + [, cntrl + q  I'm totally a terminal newb, trying to learn how to setup git using homebrew. Watching this tutorial and I was able to set my global username and email, but I'm stuck in VIM.  I can get out of it by quitting the terminal, but I have to do this every time :(  Is there a better way?


In this story, a corporation or group becomes extremely rich by investing in  long-shot research projects that, against all odds, keep succeeding. Almost like a science fiction version of Brewster's Millions. :-) The group keeps investing in increasingly far-out research and eventually develops interstellar space ships.  I think it might have been a Robert Heinlein or Isaac Asimov story. I haven't read it, so I may have some details (very) wrong.

The story starts with a space agency on earth looking for and testing twins. It seems that some are gifted in a way that allows them to communicate with each other even if they aren't speaking. The main character and his brother are such gifted twins and they are placed into a space program where one will stay on earth and the other will go into space.  As the story progresses, the brother who stays on earth ages faster then the one who went into space and creepily enough, when the space brother returns he ends up getting married to his great-great-great niece.


Following up on:      Long story short Due to a series of deadly and unholy events two PCS at my table are creatures that are both undead and humanoid. As part of their undead nature, they carry certain mechanical flaws and benefits, such as:  Desecration. Advantage on ability checks, saves and attack rolls while standing on a desecrated surface.  (This is homebrew, including the whole becoming undead) The party doesn't yet know about this mechanic, but is likely to soon find out. When they do, it's very likely they will attempt to create desecrated surfaces, instead of just finding them. Party composition (level 12): minotaur paladin of conquest, animated armor eldritch knight/abjurer, undead tabaxi beast conclave ranger/assassin/warlock of the undying, undead high elf mastermind, tiefling pact of the tome warlock. Question What mechanical options do player characters have to desecrate a surface? Mechanical options include spells, (magic) items, class features, etc. Surface can refer to the floor/ground, or a big object on which someone could stand (such as a table or chair). For now I'm only interested in the options by RAW, and possibly from any of the UA.  Note 1. If you have an interesting homebrew option that fits my search, only share that if it is tested by your table. Note 2. This question is not about whether this homebrew mechanic of their creature type is balanced or a good idea in general.

The paladin's  feature allows the paladin to     ...detect the presence of any place or object that has been consecrated   or desecrated, as with the  spell.   Similarly, the spell  allows the caster to     ...know if there is a place or object within 30 feet of you that has   been magically consecrated or desecrated.   How, other than via the spell hallow, can a place or object be consecrated or desecrated, so that it would be detected by Divine Sense or detect evil and good?  Question inspired by , where we establish that Divine Sense cannot detect whether an object is cursed.


I knows lots of people have been having problems with this tutorial but I haven't found anyone with the specific problem that I have (I've been looking for a while).  The script I have so far:  import bpy   rows = 5 columns = 5  r = 0 c = 0  for i in range(0, rows*columns):     if c == columns:         r += 1         c = 0      bpy.ops.mesh.primitive_cube_add(location = (r, c, 0))     bpy.context.scene.cursor_location = bpy.context.active_object.location     bpy.context.scene.cursor_location.z -= 1     bpy.ops.object.origin_set(type='ORIGIN_CURSOR')     bpy.ops.object.transform_apply(scale=True)      bpy.context.active_object.scale.x = 0.5     bpy.context.active_object.scale.y = 0.5     bpy.context.active_object.scale.z = 5      bpy.ops.anim.keyframe_insert_menu(type='Scaling')      bpy.context.active_object.animation_data.action.fcurves[0]. lock = True      bpy.context.active_object.animation_data.action.fcurves[1]. lock = True      bpy.context.area.type = 'GRAPH_EDITOR'      step = 100000/ (rows*columns)      bpy.ops.graph.sound_bake(filepath="C:\Users\Stephen\Music\Arcade Blaster - Reboot.wav", low=i*step, high=i*step + step)      bpy.context.active_object.animation_data.action.fcurves[2]. lock = true      c += 1     I don't understand any of the error.  Can someone help solve/explain the error?  Thanks!

So, I am following a , and it is using Python code to create an audio visualizer in Blender. Now, I've always been a coding geek, but I don't actually know Python. I've taken a few shots at it but overall, I don't know Python, however, I can read and understand the code because I know basic programming concepts. Now, I'm following this tutorial as closely as I can (the tutorial does not provide code to copy and paste) and I am getting a syntax error. As far as I can tell, there is no syntax error. The line of code (specified by the error message) appears perfect. This line of code is supposed to set the 3D cursor to the active object's origin. Here's the catch: if I run that exact same line of code in the console, it executes just fine. So here's the error message I get:  File "C:\Me\Blender\Blender Projects\audio visualisation.blend\AudioVisualizer", line 17 bpy.context.scene.cursor_location = bpy.context.active_object.location    ^ SyntaxError: invalid syntax location: <unknown location>:-1   It tells me to look in the console for error message, but the console doesn't output anything.    Thanks!  EDIT: Alright. I've tried all the examples and all the procedures that have been suggested by you guys, but it keeps feeding me errors. According to the console, one of the problems it is spitting out is in C:\Program Files\Blender Foundation\Blender\2.74\scripts\modules\bpy\ops.py. This makes me think there is a bug in the API that is causing one of the many errors. EDIT: Here are the error messages I get for my code. Original Code:  Error:   File "C:\Gannon\Blender\Blender Projects\audio visualisation.blend\Audi o Visualizer", line 35     bpy.ops.graph.sound_bake(filepath="C:\Gannon\Blender\Sounds\Music\Batty McFa dden.mp3", low=i*step high=i*step+step                           ^ SyntaxError: invalid syntax    gandalf3's Code and zeffii's Code are essentially the same with alternative formatting which changes the line numbers where the error occurs.  Error: Unsupported audio format  Traceback (most recent call last):   File "C:\Gannon\Blender\Blender Projects\audio visualisation.blend\Audio Visua lizer", line 42, in <module>   File "C:\Gannon\Blender\Blender Projects\audio visualisation.blend\Audio Visua lizer", line 35, in spiral   File "C:\Program Files\Blender Foundation\Blender\2.74\scripts\modules\bpy\ops .py", line 189, in __call__     ret = op_call(self.idname_py(), None, kw) RuntimeError: Error: Unsupported audio format


Is there a way to temporarily disable apps I downloaded from the Google play store without having to uninstall them?

There are two memory hungry apps, Facebook and Facebook Messenger, which I want to disable at times but not always. I used:   settings → apps → downloaded → Facebook → force stop settings → apps → running → Facebook → <weird service name(s)> → stop settings → apps → all → Facebook → force stop   But the app restarts after few minutes, often accompanied by lots of thrashing. Ideally I would like to disable the app and remove it from memory until I decide to use it. What is the best possible solution?  Android version is 4.4.4, almost stock, not rooted.


Good Day,   I am new to Linux (Raspberry) and am trying to get notify-send to work from a script (see below).  Notify send works from the terminal CLI and displays on my GUI.  But it does not work from the script.   I am using Raspberry Buster - with all updates.  #!/bin/bash  # This should point to the pivoyager executable PIVOYAGER=/usr/local/bin/pivoyager  while true; do    # Phase 1: Check every 5 seconds if we are USB powered.    #          If we are not on USB power, go to phase 2.    while $PIVOYAGER status flags | grep "pg";    do       sleep 5    done      # Phase 2: Do something before shutdown. (optional)    #          e.g. send an email, warn users, etc.    #notify-send "We are on Battery Power.  Save all your work."    sleep 30       # Just check if power was miraculously restored.    if ! $PIVOYAGER status flags | grep "pg"; then       break    else       notify-send "Power was restored. Shutdown aborted!"    fi done  # Phase 3: Initiate the shutdown. #          - Enable automatic power on once USB power is restored. #          - Program full power cut in 25 seconds. $PIVOYAGER enable power-wakeup $PIVOYAGER watchdog 25 sudo shutdown now   Thanks in advance for your help.

#!/bin/bash export DISPLAY=:0 state=$(upower -i $(upower -e | grep BAT) | grep --color=never -E "state" ) stat=${state:25:32} batperct=$(upower -i $(upower -e | grep '/battery') | grep  -E "percentage:") bat=${batperct:24:26} intbat=$(echo $bat | cut -d'%' -f1) if [ "$intbat" -lt "15" -a "$stat" == "discharging" ]; then     notify-send 'battery low..! please plugin charger..... charge is only' "$intbat"     fi     The script runs fine when run as a normal user (bash script.sh). The desktop notification is displayed.  If I run it as root with sudo bash script.sh, the desktop notification is not displayed.  How can I use notify-send to notify users as root?  I am using Arch Linux.


I tried to install brave in linux using the command below, but the following error is showing: curl -s https://brave-browser-apt-release.s3.brave.com/brave-core.asc | sudo apt-key --keyring /etc/apt/trusted.gpg.d/brave-browser-release.gpg add -  gpg: no valid OpenPGP data found.

I want to install Brave Web Browser . I went to the website's download section but it has a method which is less user friendly , difficult to understand . I want to know a Simple easy way to install Brave Web Browser on Ubuntu 16.04


As far as I understand, un*x load by definition is an integral measure, averaged over a predefined and quite long time periods. On the other hand, CPU utilisation can be considered a temporary measure: although technically speaking it's still measured and averaged over a time period, this time period is actually very short. The end result is that when a cpu-intensive process terminates, the CPU utilisation drops immediately, while the load value decreases gradually over time. So you may have a computer doing actually nothing at the moment, while the load is still high, only because it did not have enough time yet to decrease. As such, the measure is not quite suitable for situations where the actual cpu load drammatically changes.    Now: is it possible to measure a 'load'-like value over a fraction of a second time periods? I do not mean printing it ten times a second, because it's trivial. I mean averaging the number of run-queued processes over 1 ms or 100ms periods rather than over 15 minutes.

If CPU is running 100% usage, other processes should be put inside a run queue. Which command can I use to get the size of the run-queue? vmstat seems to return a related value of the CPU like below:  procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----  r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st  0  0      0 875128 576328 2147136    0    0     1     4    3   11  0  0 99  0  0   According to the manual, "r: The number of runnable processes (running or waiting for run time).", the column r indicates the number of processes including both running and wait processes. How can I just get the number the waiting processes?


I'm still running Ubuntu 11.10.  Can I upgrade to 14.04 directly from 11.10, or is there a certain upgrade-path one needs to follow?  Also, is 14.04 stable enough, or is it better to stick to an earlier version for now?

I am currently using Ubuntu 10.04. I know there is a 10.10 release, but can I upgrade directly to 11.04? Could you walk me through the steps please?


My first section title clashes with my header, but does not for any subsequent section titles. How can I fix this?      %Preamble \documentclass[british]{report} \usepackage[utf8]{inputenc} \usepackage[a4paper,left=25mm, right=25mm,top=25mm,bottom=25mm]{geometry} %Formats page \usepackage{babel} \usepackage{graphicx} %Allows images \graphicspath{ {images/} } %Sets image folder location \usepackage[useregional,showdow]{datetime2} %Allows dynamically updating date \usepackage{fancyhdr,lastpage} %Headers and Footers \pagestyle{fancy} \fancyhead[C]{     \title{XXX: Xxxx 12 Xxxxxxxxx Xxxxxxxxxxx - Xxxxxxxxx 1}\\ \author{Xxxx Xxxx Xxxxxx Xxxxx}\\     XXX: 12345678 $\vert$ XXX: 12345678} \fancyfoot[C]{$\thepage$ of $\pageref{LastPage}$}  \fancypagestyle{empty}{\renewcommand{\headrulewidth}{0pt}\fancyhead{} \fancyfoot[C]{$\thepage$ of $\pageref{LastPage}$}}    %Document Information \title{XXX: Xxxx 12 Xxxxxxxxx Xxxxxxxxxxx - Xxxxxxxxx 1} \author{Xxxx Xxxx Xxxxxx Xxxxx}   %Document Content \begin{document} \maketitle  \section*{Question 1} \setcounter{page}{2}   \pagebreak \section*{Question 2}  \pagebreak \section*{Question 3}  \pagebreak  \end{document}

I am having trouble typesetting multi-line headers using fancyhdr The header on the first page behaves differently than the header on subsequent pages. The first page header has no depth, but produces a greater vertical displacement on subsequent pages.  Here is a sample tex file to illustrate the difficulty  \documentclass{article}  \usepackage{fancyhdr}  \chead{line 1\\line 2\\line 3\\line 4\\line 5\\line 6\\line 7\\line 8}  \cfoot{footer}  \fancypagestyle{plain}{}  \pagestyle{fancy}  \begin{document} \thispagestyle{fancy} page 1 \newpage page 2 \newpage page 3    \end{document}


In my table id column's datatype is int.  And I have a list of items' ids to be selected.  So, here is some piece of my code:  DECLARE @user_list SELECT @user_list=( SELECT user_list FROM sometable WHERE rowNum=xxx ); SELECT * FROM anotherTable WHERE user_id IN(@user_list)   but it doesn't work, the error msg like :      can't convert varchar to int   Thanks!

How do I parameterize a query containing an IN clause with a variable number of arguments, like this one?  SELECT * FROM Tags  WHERE Name IN ('ruby','rails','scruffy','rubyonrails') ORDER BY Count DESC   In this query, the number of arguments could be anywhere from 1 to 5.  I would prefer not to use a dedicated stored procedure for this (or XML), but if there is some elegant way specific to , I am open to that.


If I want to change the pointed value without changing the pointer's address, what should I do?  In 3, *d=*b will return segmentation fault in running time. I think it is because the *d is not pointed to any memory space. This also explains why 2, works. However, for 1, *a and *b pointed to memory with same size, why it will return segmentation fault here?  void main(void){     char *a="abcd";     char *b="1234";     char *c=(char *)malloc(sizeof(char));     char *d;     *a=*b; //1.segmentation fault     *c=*b; //2.ok     *d=*b; //3.segmentation fault }

The following code receives seg fault on line 2:  char *str = "string"; str[0] = 'z';  // could be also written as *str = 'z' printf("%s\n", str);   While this works perfectly well:  char str[] = "string"; str[0] = 'z'; printf("%s\n", str);   Tested with MSVC and GCC.


Consider the set $A ⊂ M_3(\Bbb R)$ of $3 × 3$ real matrices with characteristic polynomial $x^3 − 3x^2 + 2x − 1$.  Then $A$ is a compact subset of $M_3(\Bbb R) \cong \Bbb R^9$.  Now this polynomial is irreducible over rationals and it is equivalent to the companion matrix $$     \begin{pmatrix}     0 & 0 & 1 \\     1& 0 & -2 \\     0 & 1 & 3 \\     \end{pmatrix}. $$  Now am I missing any important theorems or details?

Consider $$X=\Big\{A \in M_3(\Bbb R): \rho_A(x)=x^3-3x^2+2x-1\Big\}$$ where $\rho_A(x)$ is the characteristic polynomial of $A$ and $M_3(\Bbb R)$ is the space of all $3 \times 3$ matrices over $\Bbb R$. Is $X$ compact in $M_3(\Bbb R)$ ?   My try: I confused with only the $2x$ term in $\rho_A(x)$. Because , if the $2x$ term not appear , then $X$ becomes  $$X=\{A \in M_3(\Bbb R): \text{trace}(A)=3,\det A=1\} $$ which is unbounded, since $$(\forall n \in \Bbb N):\begin{pmatrix} 1&0 & n\\0&1&0\\0&0&1 \end{pmatrix} \in X$$ But here the problem is, the appearance of $2$.  I Know  $$2=A_{11}+A_{22}+A_{33}$$ so I think in this case the set becomes bounded and closed Any help?


I have created an application which uses .NET 3.5. However, some Windows XP machines give the following error:     Could not load file or assembly 'System.Core, Version=3.5.0.0,   Culture=neutral, PublicKeyToken=b77a5c561934e089' or one of its   dependencies. The system cannot find the file specified.   It's because they have installed a version older than 3.5. How could I check the .NET version decently? I mean I can't check it from my application itself since it's looking for the 3.5 DLL files when the program is launched.  What I thought of, is creating a very simple program using .NET 2.0, and then checking what versions are installed (this program as a launcher). However I'd like to hear your opinions.

A similar question was asked , but it was specific to .NET 3.5. Specifically, I'm looking for the following:   What is the correct way to determine which .NET Framework versions and service packs are installed? Is there a list of registry keys that can be used? Are there any dependencies between Framework versions?


I am applying to some schools in the UC system for graduate school, and I have to write a Statement of Purpose and a Personal Statement. I was wondering if there are some good examples online, so I can have a better idea of what is expected.

The internet is littered with information on what makes a good SOP, but I would like to ask a specific question regarding mentioning one's research interests in SOP.  What points should a student keep in mind while writing her statement of purpose? If there is exactly one specific professor the student is targeting, it makes sense to talk of one of his recent papers and ideas for extending its results in the SOP.    If 1) there are a couple of preferred professors or more, 2) each of them has multiple research interests and 3) the student is unable to zero in on a field or topic, how should the student tailor her SOP to make it appealing to more than one professor? Should the student worry about the feasibility of her ideas in the SOP? Is an extensive literature survey in the relevant field necessary before putting anything in the SOP?


This does not work:  $stmt = $pdo->prepare("SELECT * FROM location ORDER BY ? ASC"); $orderValue = "location_name"; $stmt->execute([$orderValue]);   How can I ortder the result by location_name?

Why can't I pass the table name to a prepared PDO statement?  $stmt = $dbh->prepare('SELECT * FROM :table WHERE 1'); if ($stmt->execute(array(':table' => 'users'))) {     var_dump($stmt->fetchAll()); }   Is there another safe way to insert a table name into a SQL query? With safe, I mean that I don't want to do  $sql = "SELECT * FROM $table WHERE 1"


Continuing to work on writing clean proofs while studying for a qualifying exam (1st try as I enter grad school so there are no stakes involved). I can "see" the rationale for the titular proof in my head and can explain it (sort of) in words but I'm at a loss for the cleanest and most concise way to write it out. Here's my attempt...     $\mathbf{Theorem}$:  group $G$, and subgroups $H$ and $K$ which form a   "chain" of characteristic subgroups $G \blacktriangleright H  > \blacktriangleright K$ show that $G \blacktriangleright K$.      $\mathbf{Proof}$: The groups of automorphisms on $G, H$, and $K$ are   denoted as $\operatorname{Aut}(G), \operatorname{Aut}(H)$, and   $\operatorname{Aut}(K)$ respectively.        Every element has $\operatorname{Aut}(H)$ is "embedded" in some   element of $\operatorname{Aut}(G)$ because $H$ is characteristic in   $G$.      Similarly every element of $\operatorname{Aut}(K)$ is "embedded" in   some element of $\operatorname{Aut}(H)$.      Since $K \blacktriangleleft H$ we have every element of   $\operatorname{Aut}(H)$ has some element of $\operatorname{Aut}(K)$   embedded in it.      Smiilarly, since $H \blacktriangleleft G$ we have every element of   $\operatorname{Aut}(G)$ has some element of $\operatorname{Aut}(H)$   embedded in it.      Clearly we have that every automorphism of $G$ has an automorphism of   $K$ embeded in it. Hence $K \blacktriangleleft G$, $\square$.   $\mathbf{Self Critique}$: I believe that speaking of "embedding" without being very clear about what that means is a problem but am unsure how to flesh it out for precision's sake (and possibly that might make this proof inaccurate?)  It was suggested that this is a duplicate of  which it is not. This question is tagged as "proof-writing" as in I needed feedback in writing a better version of my own proof and not simply copying another person's proof.

Here, I wanted to verify that:     The property of being characteristic is a transitive relation among subgroups of a group $G$.   For subgroups $N,H\leq G$, we have $N$ char $G$ and $H$ char $N$. So $N$ char $G$ implies: $$\forall\psi\in Aut(G); \psi(N)=N$$ $H$ char $N$, so for all elements in $Aut(N)$, $H$ is remained never changing. Especially, when I take $\psi'=\psi|_{N}$ then $\psi':N\to Aut(N)$ would be in $Aut(N)$ and $\psi'(H)=H$. Since the last equality is true for $H$ and the maps, caused by restriction on $N$, then I have $H$ char $G$.  Honestly, I am inly not satisfied form the conclusion here and think I am losing something. Thanks for your hints.


i am trying to split a video file into equal file size parts with ffmpeg.  At first i get the file size of the original and divide it with the desired number of parts to get the file part's file size.  Then i try to do something like :  ffmpeg.exe -y -i video.mp4 -fs 1000000 video-part1.mp4 ffmpeg.exe -y -i video.mp4 -ss [LAST_VIDEO_PART_DURATION] -fs 1000000 video-part2.mp4  but i do not get satisfying results because the -fs does not work as it is required.  The part file sizes become not the same.  Anyone who has a solution for this ?  Thanks !

i want to split a video file by size using ffmpeg.  Do you know how to do that ?  Do i have to calculate the duration that corresponds to each size ?  Thank you.


I read  that since $\sin(z)$ has an essential singularity at $\infty$, $1/\sin(z)$ also has an essential singularity at $\infty$. This got me thinking: Is it true that if $f(z)$ has an essential singularity at $z_0$ then $1/f(z)$ also has a singularity at $z_0$ and can this be proved in terms of Laurent series?

Let $\Omega$ be a non-empty, open subset of $\mathbb C$. Consider an holomorphic function $f:\Omega \setminus \{z_0\} \to \mathbb C$ and suppose we know $z_0$ is an essential singularity of $f$.   I am wondering what we can say about the function $\tilde{f}:=\frac{1}{f}$ and its singularity in $z_0$. Do you know any theorem that answers to this question?  Actually, I can't prove anything, since I do not know the answer: I've studied some examples. For instance, if you take $f(z)=e^{\frac{1}{z}}$ then $\tilde{f}$ will still have an essential singularity, hasn't it?   On the other side, if we take $f(z)=\sin(\frac{1}{z})$ then I think that $z_0=0$ becomes a limit point of poles for $\tilde{f}$ (so we can't classify it, because it isn't an isolated singularity).   Wha do you think? Do you know any useful theorem concerning this? Thank you in advance.


I'm currently on a server that's going to be shut down, I have a few things on that server I would like to save so I was wondering if there is any way to convert this world into my own singleplayer world.

I had a Minecraft world on Minefold.  I archived my Minecraft world just before Minefold closed about a year ago.  I'm trying now to open the world in my local Minecraft installation on OS X, but it doesn't show up in the worlds list.  To import it, I simply unzipped the archive from Minefold into my ~/Library/Application Support/minecraft/saves folder.  I'm running Minecraft 1.8, and I don't have any mods installed.  There's no error; the world just doesn't show up in my list of worlds after I click [Singleplayer] (or [Multiplayer]).  Now, the big clue is that the directory structures are different between my locally-created worlds and the world created on Minefold, but I can't figure out how to adapt the files to make them match:  This is a screenshot of my saves folder. I've circled in blue "local" and "minefold", which contain data files for the local and Minefold worlds, respectively.    I bracketed similar filenames in both worlds, but I'm flummoxed in that the Minefold version has three (3) sets of data files, whereas the local world has only one (1) set of files (even though I have visited Nether in the local world).  How do I load my old Minefold world locally?


In whirling block problem as given below, I understand that Tension force is acting as central force in its motion so its angular momentum is conserved.  With time r will decrease if system is left isolated, and since angular momentum is conserved as r decreases its tangential velocity will increase. I want to know what force provides this change in tangential velocity of object.  I searched about this and found whats below but could not understand the tangential equation.

A mass is attached to a rope, and put into a circular motion. If I pull the string from the center, the tangential speed of the mass will increase (by conservation of angular momentum).   I am applying a force only in the radial direction, so how can the tangential velocity increase if there is no tangential force?


I'm trying to understand how USART works on a STM32 nucleo board that has a built-in ST-link. Here's the high level diagram I found from the user manual.   It's apparent that that RX and TX pins of the MCU are connected to TX and RX of the ST-link as expected, but what happens next? how does ST-link forward these signals to the laptop that's using serial interface for sending/receiving serial data?

I have been reading up on UART, and I see it works by connecting TX<->RX and RX<->TX of receiver and transmitter. The example I couldn't wrap my head around though is your MCU being able to TX the data to a serial monitor that you could view on your PC using teraterm, let's say. I tried it and it does work. I did specify the TX and RX pins for UART in my code, but they're not connected to anything. Can someone help me bridge this gap? Does it work like for RX too? (receiving data from the serial monitor into your MCU)?


I always get this black screen after booting up ubuntu, unless I use "nomodeset", sure it boots but the resolution is kind of crappy. I'm using the a6-7480 radeon r5. Am I lacking drivers or something else? help please

I am trying to boot Ubuntu on my computer.  When I boot Ubuntu, it boots to a black screen.  How can I fix this? Table of Contents:


I have used seekbar like quite a few times but never faced problem. Yesterday I was dealing with Fragments which I am not too familiar with but implemented successfully. But at the end of the day when I included seekbar to the fragment and problems started. Not sure this is coz of fragments or what. Here is my code.   fragment_main.xml  <LinearLayout> <SeekBar     android:id="@+id/seek"     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:max="100"/> </LinearLayout>   FragmentMain.java  public class FragmentMain extends Fragment {  final static String TAG = "FragmentMain"; TextView mainTextView;  @Nullable @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {     View view = inflater.inflate(R.layout.fragment_main, container, false);      SeekBar seekBar = (SeekBar) getActivity().findViewById(R.id.seek);     seekBar.setProgress(40);      return view; } }   This FragmenMain is the center page of my viewPager.   I dont know why my code is crashing giving NullPointerException at setProgress.  Feel free to suggest edits.

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


Ok so I'm new with blender, as I was working on my project the object disappeared. The grey colour of the object disappeared. I can still see it just not the grey colour. Think I must have clicked or pushed something because Ctrl+Z doesn't work.

I am brand new and I'm trying to switch back to solid view on my model...  At the moment I have this...   And I want this...    EDIT:


I am getting grub rescue error on boot up. Error is like:     /boot/grub/i386-pc/normal.mod not found   I typed the ls command to see the partitions available.  Result of ls is:     hd0 (hd0,msdos1) (hd0,msdos5)   On command: ls (hd0,msdos1) am getting a list of folders available .  But /boot folder is not visible here.  Though, normal.mod is available under /usr/lib/grub/i386-pc/ directory, but cp command is not working on shell.  The  given in comment section works fine if /boot directory is present. But, in my case it is not showing any /boot directory under (hd0, msdos1) partition.   Any solution for the above problem or do I need to dump OS again?  Thanks in advance.

error: file '/grub/i386-pc/normal.mod' not found. grub rescue>   What can I do? I just sit and stare at it.   I found my old netbook (Dell Inspiron 1010) which I have not used for about four years. I replaced Windows XP with Ubuntu 12.10. I used my bootable USB drive. I installed and rebooted. I got the message that normal.mod is not found.   What should I do? Type exit, reboot, or quit? Should I re-install?


I have moved a zipped file to a directory which does not exist. It resulted in creating a new file. But I am not able to open/unzip it.

I was attempting to utilize the mv command to move a file onto a remote server. I ended up executing the command...  mv sqlreport.php myuser@mywebsite.org   Unfortunately, this did not work. Worse, my file seems to have disappeared. A new file, myuser@mywebsite.org, has appeared, but it is not a directory (In that I cannot cd into it).  Any tips on where my file may have gone, and how to rescue it?


I need help in installing Xampp on Ubuntu 14.04LTS?

I am using ubuntu 14.04. I want to install lampp but don't know how to install it. Can I get some help for installing lampp on my Ubuntu.


I have  about the EL&U blog being gone and though I'd try the other blogs. They're all gone! (Apart from the main SE blog.)    Where are the blogs?

I seem to be the unlucky recipient of a 302 redirect from the blogoverflow site, and was asked by Grace Note to upload the issue here. While trying to access the DIY blog site, I'm getting bounced over to the generic SE blog page. I've tried resolving this by changing DNS servers, clearing my browser cache, and trying a different browser. Others going to the same site aren't experiencing the issue, but I'm at a loss for what's different on my system that would cause this. Here's the wget output of the redirect:  --2014-02-18 14:59:28--  http://diy.blogoverflow.com/ Resolving diy.blogoverflow.com (diy.blogoverflow.com)... 67.228.172.87 Connecting to diy.blogoverflow.com (diy.blogoverflow.com)|67.228.172.87|:80... c onnected. HTTP request sent, awaiting response...    HTTP/1.1 302 Found   Date: Tue, 18 Feb 2014 19:59:28 GMT   Server: Apache   X-Powered-By: PHP/5.4.22   Location: http://stackexchange.com/blogs   Content-Length: 1001   Connection: close   Content-Type: text/html; charset=UTF-8 Location: http://stackexchange.com/blogs [following] --2014-02-18 14:59:28--  http://stackexchange.com/blogs Resolving stackexchange.com (stackexchange.com)... 198.252.206.140 Connecting to stackexchange.com (stackexchange.com)|198.252.206.140|:80... conne cted. HTTP request sent, awaiting response...    HTTP/1.1 200 OK   Cache-Control: private   Content-Type: text/html; charset=utf-8   X-Frame-Options: SAMEORIGIN   Date: Tue, 18 Feb 2014 19:59:28 GMT   Content-Length: 16775 Length: 16775 (16K) [text/html] Saving to: ‘index.html.1’       0K .......... ......                                     100% 1.04M=0.02s


Through some research online, I found out that the sun's corona is hotter than it's surface. How's that even possible?? Is the sun releasing it's heat from the surface!!! Need a complete answer.

How does the surface of the photosphere conduct thermal energy from the convective zone to the corona, while remaining at such a relatively low temperature itself?  It seems odd to me that the photosphere is wedged between the convective zone and the corona, both of which are millions of degrees in temperature, while the photosphere itself is observed to be much colder by comparison - approx. 5-10 thousand degrees.  Based on my understanding of convection, this would require thermal energy to jump from the convective zone directly to the corona, and somehow skip the photosphere surface material in-between.  Is there a different model of convection that explains this? Or is there a type of matter with thermal conductive properties that could accomplish this?  EDIT: Perhaps the convective zone is emitting heat as a different form of energy, such as electromagnetic - thereby allowing the outer layers to cool and sink in standard convection, but without directly heating up the surface of the photosphere.  Based on my understanding of the standard model of the sun, the following layers should be present:  Predicted:   The core A central area with pressures high enough to induce hot fusion of atomic nuclei The radiative zone A spinning ball of somewhat solid material surrounding the core, through which energy is conducted via radiation   Semi-observable:   The convective zone A layer of plasma surrounding the radiative zone, through which energy is conducted thermally via convection flows - millions of degrees in temperature This is the subject of some 2012 studies by NASA in coordination with various other reputable institutions, which observed that the sun's convection appears to be "anomalously weak"    Observable:   The surface of the photosphere The border between the convective zone and the corona - temperature in the ballpark of 5-10 thousand degrees The corona The outer plasma atmosphere, where flares take place - millions of degrees in temperature


I am trying to write Unit test cases for Activities in my app by extending the test class with ActivityUnitTestCase. I could successfully run the test cases earlier but now I'm always getting the exception while running them. Even though I'm pretty familiar with handling NullPointerExceptions, I couldn't figure out the problem that's causing this. I couldn't find any similar questions so I'm posting this one.   Stack trace shows me there is a null object reference at this line in my code  activity = startActivity(mIntent, null, null);   But the startActivity method is supposed to get the instance of the activity I'm testing. I'm not sure why it's returning null.   Here is the Stack trace.  java.lang.NullPointerException: Attempt to write to field 'android.os.IBinder android.app.ActivityThread.mLastIntendedActivityToken' on a null object reference at android.app.Activity.performCreate(Activity.java:6372) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119) at android.support.test.runner.MonitoringInstrumentation.callActivityOnCreate(MonitoringInstrumentation.java:346) at android.test.ActivityUnitTestCase.startActivity(ActivityUnitTestCase.java:158) at com.abc.test.MainActivityTest.access$100(MainActivityTest.java:16) at com.abc.test.MainActivityTest$1.run(MainActivityTest.java:34) at android.app.Instrumentation$SyncRunnable.run(Instrumentation.java:1891) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:145) at android.app.ActivityThread.main(ActivityThread.java:6117) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)  Test running failed: Instrumentation run failed due to 'java.lang.NullPointerException'   Here is the Test class  public class MainActivityTest extends ActivityUnitTestCase<MainActivity>{      private Intent mIntent;     private MainActivity activity;      public MainActivityTest() {         super(MainActivity.class);     }      @Override     protected void setUp() throws Exception {         super.setUp();         //Create an intent to launch target Activity as it is not automatically started by Android Instrumentation         mIntent = new Intent(getInstrumentation().getContext(), MainActivity.class);         //Start the activity under test in isolation, in the main thread to avoid assertion error.         getInstrumentation().runOnMainSync(new Runnable() {             @Override             public void run() {                 activity = startActivity(mIntent, null, null);             }         });     }      @Override     protected void tearDown() throws Exception {         super.tearDown();     }      /**      * Tests the preconditions of this test fixture.      */     @SmallTest     public void testPreconditions() {         assertNotNull("MainActivity is null", getActivity());     }      @MediumTest     public void testSecondActivityWasLaunchedWithIntent() {         // Get the intent for the next started activity         final Intent launchIntent = getStartedActivityIntent();         //Verify the intent was not null.         assertNotNull("Intent was null", launchIntent);         //Verify that LaunchActivity was finished         assertTrue(isFinishCalled());     } }


I want to protect database from SQL Injection. How can I use PDO or mysqli mysql_real_escape_string in this code. MY PHP Version is 5.6.36    public function LoginUser($email, $password)   {      /*      * echo $password= addslashes("$password"); die;      */     $sql = "SELECT ref,firstname,contact,email,parent_id FROM `pro` where passe=password('$password') and email='$email' "; // or login='$email'     $result = mysql_query($sql);     return $data = mysql_fetch_assoc($result);   }

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


Can someone help me determinate the nature of the following series? $$ \frac {a^n}{ (1 + tg(\frac{3}{2}) ( 1+tg(\frac {3}{4}) + ... (1 + tg(\frac{3}{2n})) }$$

Consider the series:  $$a) \sum_{n=1}^\infty \frac{a^n}{ \prod_{k=1}^n \ (1+\sin\frac{1}{2k})}$$ $$b) \sum_{n=1}^\infty \frac{a^n}{ \prod_{k=1}^n \ (1+\tan\frac{3}{2k})}$$  Showing that these two are convergent (and absolutely convergent) it's no big deal for  $a\in R^*$. But I couldn't figure out how to solve it when $a=1$. My guess is that the general term has to be brought to another form. And that is my question: how to prove convergence when $a=1$.  Thanks for helping with this!


A  family of sets F is called interesting if $$\exists n \in \omega \forall X (X \in F \iff \forall Y (Y \subseteq X \land |Y| \leq n \implies Y \in F)$$ I have the following lemma: If F is an interesting  family and $x\in F$, then there is a maximal $Y \in F$ (according to the $\subseteq$), such that $X \subseteq Y$. I need to shouw that this lemma is equivalent to the axiom of choice. My attempt: I have noticed that this lemma has a tight connection with .(which is equivalent to the Axiom of Choice) It's easy to see that every interesting Family is of finite character. So the given lemma is a bit "stronger" than the Teichmüller–Tukey lemma. But can I conclude that lemma and the AC are equivalent from that? Probably just the first direction (Lemma $\implies$ Axiom of Choice). But I can't figure the other direction. Any tips? PS: I think the question was wrongfully closed: The given solution has nothing to do with the task.

Let F be a set of sets. We say a set is n-pretty  (it's writen in my text book, I don't know the exact name)(n is fixed nat. number) if $$\forall X (X \in F \iff \forall Y (Y \subseteq X \land |Y| <= n \implies Y \in F)$$. And we say that a set is finite-pretty if: $$\forall X (X \in F \iff \forall Y (Fin(Y) \land Y \subseteq X \implies Y \in F)$$ So the task is to find if every n-pretty set is finite-pretty and if every finite-pretty set is n-pretty. I think that every finite-pretty set is n-pretty. Since it's true for every finite set, it will be true for every set with cardinality n. But I can't seem to  prove it in terms of set theory. And what about the other direction ? Any tips?


On , it is stated that posts enter community wiki mode when it has been edited six times by the original owner.  Why is that? I often edit posts for small, merely cosmetic reasons and do not want them to be turned wiki. I'm well aware of the automatic preview, but even after carefully considering an edit, I often (multiple times per post) notice something a few minutes or hours later.  The number stated in above link may not be actually correct. The current value (and implementation details) seem to be unknown. If the actual number were, say, 20, I would not mind, since a value that high ought not to cause any trouble. On the other hand, if it were 5, I definitely would.  Edit: It seems a main concern is that users would be able to bump often. In this case, there are some rather easy ways to prevent gambling in the comments to , so I don't this this should be an issue.

Personally I think not. If the concern is spurious bumping then simply stop bumping the post after some arbitrary edit.  This site might be part-Wiki, part-Q&A but I think its clear that people feel a sense of ownership over their questions and answers, which CW diminishes to some respect.  The question is: does this happen enough such that people won't maintain their posts as the facts change? I suspect it does.  Edit: Let me just add that there are plenty of ways of bumping your post without editing it currently, such as:   Retagging the question (assuming you wrote an answer); Editing the question (assuming you wrote an answer); Editing someone else's answer; Adding another answer to the question;  Using a sock puppet to add another answer. Have a sock puppet edit it's own answer. Have a sock puppet edit someone else's answer (provided it has enough rep). Have a sock puppet edit the question/tags (provided it has enough rep, or owns the question).   AFAIK all of these things will bump the question to the front page and none of them involves editing your post. So if someone wanted to constantly bump a question they already can. I haven't seen a problem like this to date, which suggest to me that we don't have a problem with spurious bumping.


I would like to customize the settings for text highlighting on TexStudio.  I'm working with lot of big and small equations and using the breqn package. Here is some sample code:  \documentclass{article} \usepackage{amssymb} \usepackage{amsmath}  \usepackage{mathpazo} \usepackage[mathpazo]{flexisym} \usepackage{breqn} \newcommand{\eq}[1]{\begin{dmath}#1\end{dmath}}  \begin{document}     A small inline equation: $small$\\      A regular non-inlined equation:     \begin{equation}         Regular = \omega \times \delta     \end{equation}      A big equation that might need line breaks:     \begin{dmath}         Big = \omega \times \delta + bla + bla + bla + bla + bla  + bla + bla + bla + bla  + bla + bla + bla  + bla + bla + bla       \end{dmath}      The way I'd like to deal with this:     \eq{something = \omega + \delta}     \end{document}   And the result is fine:    However, when working on the text editor of TexStudio, the code looks like this:   My question: Is there a way to get TeXstudio to understand that the dmath environment is an equation environment so that it does not highlights the math symbols in red but use the formatting used in the equation environment? Would it be possible to do the same with the custum command as well?

I've made a mymacros.sty file which I would like my LaTeX files to be able to access with commands that I've defined. I've managed to get it to work by putting \usepackage{mymacros} in my preamble.   However when I try to autocomplete I can't. I looked at this question:     ), which recommends 3 ways of doing this, none of which work for me.    The first it recommends is to have mymacros.sty open in the editor. But this doesn't work.  The second is to activate the option Editor -> Automatically load included files in the configure TeXstudio options panel. However while I have an Editor tab , there is no such option there.  The third is to using .cwl files, however I'm not sure how to go about this. In the completion tab I've noticed that there is a mymacros.sty option that has come up, which I ticked but that has had no effect. Do I need to make my own mymacros.cwl file? I've tried to look this up but haven't had any luck.  Anyone have any ideas? Thanks in advance!


Let $G$ be a group and $g \in G$. Show that $o(g)=o(xgx^{-1})$, where $o(x)$ is the order.  I've managed to show that the order of $xgx^{-1}$ is at most $o(g)$ by the following way. Denote $o(g) = n$ and $o(xgx^{-1}) = m.$ Now $(xgx^{-1})^n=xgx^{-1} \cdots xgx^{-1} = xg^nx^{-1} = xx^{-1} = e.$ But I'm not sure how to show this the other way around? Any hints would be appreciated. This doesn't seem to yet imply that the orders would equal one another.

I am trying to prove that any conjugate of $a$ has the same order as $a$.  Let $G$ be a group and let $a \in G$.  An element $b \in G$ is called a conjugate of $a$ if $b=xax^{-1}$.  My professor gave us a hint.  Prove $a^k=e$ iff $b^k=e$ for all $k \in \mathbb{Z}$ implies $o(a) = o(b)$.  My first move is to $b^k = (xax^{-1})^k = (x^{-1})^ka^kx^k = (x^{-1})^kex^k = (x^{-1})^kx^k=x^{-k+k}=x^0$  I am not sure that I am doing this correctly?  I am trying to get $b^k=e$.  However when I raise $(xax^{-1})^k$, I am not sure if I what I have done is correct?  I am kind of confused here.


for example i have : file directory: C:\Users\Desktop\program files in directory: cheese(folder) ,veggie(txt file), meat(doc file) How do i record down the names of the files and folder in the directory? Thanks in advance!!

How do I get Perl to read the contents of a given directory into an array?   can do it, but is there some method using 'scandir' or a similar term?


My /etc/crontab contains the following lines: 0      *       *       *       *       root    /usr/bin/touch /root/IT_WORKED 1      *       *       *       *       root    /bin/sh -c '/sbin/zfs snap -r zpool@snapped_$(/bin/date '+%Y.%m.%d-%H.%M.%S-%Z-A') ' 2      *       *       *       *       root    /bin/sh -c "/sbin/zfs snap -r zpool@snapped_`/bin/date '+%Y.%m.%d-%H.%M.%S-%Z_B'` "  When it's left to run, I see that the touched file is updated, so cron is clearly picking up the file on the hour. But the zfs snapshots aren't created. I've tested the 2nd and 3rd lines in shell and they both work fine as CLI commands, and snapshots are created. So why aren't they running from cron?

I want to create a log file for a cron script that has the current hour in the log file name. This is the command I tried to use:  0 * * * * echo hello >> ~/cron-logs/hourly/test`date "+%d"`.log   Unfortunately I get this message when that runs:  /bin/sh: -c: line 0: unexpected EOF while looking for matching ``' /bin/sh: -c: line 1: syntax error: unexpected end of file   I have tried escaping the date part in various ways, but without much luck. Is it possible to make this happen in-line in a crontab file or do I need to create a shell script to do this?


I am using "Invoke Duplicity" to create a perfect illusory clone of my self. The clone is currently 100ft away. I want to cast "Dominate Person" on a target 120ft away. Can I do so without moving?  For simplicity, assume I am on a flat, well-lit plain with no obstructions so I can clearly see out to 120ft.  Invoke Duplicity is a Trickery Domain feature that requires concentration and allows you to "cast spells as though you were in the illusion’s space, but you must use your own senses."  Dominate Person is a spell with range 60ft and requires concentration. It also states:     While the target is charmed, you have a telepathic link   with it as long as the two of you are on the same plane   of existence.    I know that when I cast Dominate Person, the Invoke Duplicity effect will end (since they both require concentration), but I wonder if the effect will last long enough for me to target and cast the Dominate Person spell.  This question was inspired by  and . It is not a duplicate of the latter because it is not trying to cast the second spell (Dominate Person in this case) for an instant effect. It is not a duplicate of the former because the former is a duplicate of the latter, so if this question isn't a duplicate of the latter, it therefore can't be a duplicate of the former either. If they have the same answer it does not make it a duplicate if the questions being asked are different.

The book says:     Concentration. Some spells require you to maintain concentration in order to keep   their magic active. If you lose concentration, such a spell ends.   So what happens if, for example, you are already concentrating on a spell, and cast Witch Bolt without concentrating. Would you get the initial arc of blue energy, or would it not even go off?  I am asking if you can cast a spell that says concentration without concentrating for an immediate effect. This would be useful to avoid interrupting your existing concentration. In essence, if you are concentrating on thing A (doesn't have to be a spell since other things need concentration), can you cast a concentration spell getting an immediate effect without losing concentration on thing A?  Since the definition of concentration is to keep the spell active (meaning it is already active) I would think that you would get the initial effect (if it had one) without the need to concentrate on it.


I've often seen $\mathbb{E}[X]$ instead of $\mathbb{E}(X)$, but it seems variance is almost always $Var(X)$.  E.g., Wikipedia for  and .  Is there a good mathematical reason for using square brackets for one and not the other?

My question is told in a few words: Why do you write $E[X]$ in square brackets instead of something like $E(X)$? Probably it is not a "function". How would you call it then? This question also applies for $Var[X]$.


It is known that electromagnetic waves with a high frequency possess a greater amount of energy than waves with lower frequencies. Why is this the case? Does it have anything to do with Planck's law?

This is probably a dumb question. I guess what I'm trying to ask is if radio waves travel the same speed as gamma rays, how do gamma photons carry more energy than radio photons? Do they spin faster? What other energy sources could they carry if they are moving the same speed through space?


I'm part of an external team hired to improve a software engineering company's intranet.  I have been tasked with developing a usable set of personas out of a pool of around 300 employees. The personas, along with heuristic evaluation and usability testing, will be one of the tools used to develop a design-decision making framework.  In order for the personas to be an effective tool I know I need to ask the right questions, the right way. Does anyone have some experience interviewing intranet users that they can share?

I am currently designing an interview plan in order to make a persona for our products(an ERP software, already online). So here is the outline of the questions that i want to asked:  know your user (name, age, experience, working environment, etc) know how they work know their likes about the system   know their dislikes about the system   could you give me some ideas?


I love to take photos of people in urban areas; buildings, houses, cars, motion, expression... everything. However, taking photos of people and taking photos of indoors without having any permission, might not be morally correct?   Taking a photo of another human being without his or her permission - is this ok? Taking photos of interiors (like a pub, not a house) through the windows - is this ok? Taking photos of street performers without permission of the actors - is this ok? Taking a photo of a painting that an artist is selling on the street - is this ok? Taking photos of random kids - correct or not?   From my point of view, I am not doing any harm, just looking for beauty; probably 3/4 of my photos will be deleted anyway. But I do understand that people do not feel ok to be photographed by someone. I try to ask, but you can't do that all the time; many times it is just a spontaneous moment...  Is there any 'law' I should be aware of?  EDIT  I want to only publish photos on e.g. 500px, not to sell or anything, just to share them as something I find nice.  Unfortunately, I live in the country where these rules are old and everything is regulated by the statement that photo must not disturb the privacy of the subject. But than shooting two people sitting on the bench is not legal. Etc.

If one were to take a similar path as  in shooting candid street photography today, should they be concerned about laws or other realistic norms of today? I am wondering specifically in the US speaking broadly of all states. I am not looking for legal advice, but anything that one photographer to another would caution against as potentially being grey or obviously illegal.  Similar previous question:


I'm new in the community. I have a problem while installing wine, it says:   "The following packages have unmet dependencies:  winehq-stable : Depends: wine-stable (= 5.0.0~bionic) E: Unable to correct problems, you have held broken packages."    I tried with aptitude to install all other packages that may be broken, but I don't know what to do now. My Gnome version is 3.28.2, I use Ubuntu 18.04 (Bionic) . If need more details are needed please let me know.

After upgrading from 10.04 to 12.04 I am trying to install different packages.  For instance ia32-libs and skype (4.0).  When trying to install these, I am getting the 'Unable to correct problems, you have held broken packages' error message.   Output of commands:  sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.   After running this:  sudo dpkg --configure -a foo@foo:~$ sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.


I have a Sharepoint 2010 application that consists of Sharepoint application pages and donot contain any web parts. So when I deploy the wsp of the application from the central administration the application will be globally deployed. I want avoid this and deploy the application on to a particular site. How do I accomplish this?

How can we avoid the Globally Deployment of a WSP using Visual Studio 2010?


A hint or full answer will help a lot, because I have no idea what to do.

Prove that $2^{10}+5^{12}$ is composite   I need to solve this using only high school mathematics. Any ideas?


I have noticed that as the Iron Man movies progressed Tony's arc reactor got thinner and thinner. I don't get why the movies never tried to explain this cause I find it important.  For example, in the first movie if Tony already built the arc reactor into Rhodes’ suit then how come we don't see Rhodes struggle to get in the suit with a 9 cm arc reactor in the middle? I get that he made it thinner in the next movies but in Iron Man 1 the arc reactor is clearly about 9 cm thick. Explain please.

I realize this is probably going to come off as a bit silly, but in Iron Man II how could James Rhodes easily don the Mark II armor that was designed to fit Tony Stark?  As you can see in this image (which isn't an "in universe" shot) Tony and Rhodey are roughly the same height, but it appears that Rhodey has a smaller frame than Tony, which would seem to make for an ill fit of the armor, especially for flight.  This issue could of course have been addressed by the Air Force during the retrofit with Justin Hammer.


i have a directory name with ISO&Emulator having some Important Files. and this directory is in different partition, and partition not showing in my FileManager(Nautilus). so i mount my partition and access it from terminal, but i can't get into directory because of its name.  when i tried to change directory:  cd ISO&Emulator   result:  [1] 1635 bash: Emulator: command not found bash: cd: ISO: No such file or directory [1]+  Exit 1   its taking directory name as a command. any ways for access this directory from terminal?  how to fix this?

I want to enter the following folder in the terminal:  Milano, Torino (Jan)-Compressed   How should I write the command cd to enter this directory?  Spaces and several other special characters like \, *, ), ( and ? cause problems when I try to use them in the command line or scripts, e.g.:    $ cd space dir bash: cd: space: No such file or directory  $ cat space file cat: space: No such file or directory cat: file: No such file or directory  $ cat ( bash: syntax error near unexpected token `newline'  $ echo content >\ > ^C  $ ls ? (  )  *  ?  \   How do I enter file or directory names that contain special characters in the terminal in general?


I'm trying to learn programming in general using C# as my first language so please bear with me as I do not know how to exactly asked what I need to ask. Basically I'm following along code from a YouTube video and I hit a brick wall. Here's the entire source code using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks;  namespace CoffeeNCodeStructures {     public class Program     {         public class Person         {             public string name;             public int age;              public Person(string name, int age)             {                 this.name = name;                 this.age = age;             }              public string PrintPerson()             {                 return "Name: " + name + " - Age: " + age;             }         }         static void Main(string[] args)         {             List<Person> people = new List<Person>();              for (int i = 0; i < 2; i++)             {                 Console.WriteLine("Please enter your name: ");                 string name = Console.ReadLine();                  Console.Write("Please enter your age: ");                 int age = Convert.ToInt32(Console.ReadLine());                  people.Add(new Person(name, age));             }              foreach (var item in people)             {                 Console.WriteLine(Person.PrintPerson());             }              Console.ReadLine();         }     } }  Visual Studio is throwing me this error  error CS0120: An object reference is required for the non-static field, method, or property 'Program.Person.PrintPerson()'  The issue is in this code block specifically             foreach (var item in people)         {             Console.WriteLine(Person.PrintPerson());         }  Person.PrintPerson() won't work. What am I doing wrong in the code? I hope this question isn't to vague or bad. I'm new and really wanna understand the code in front of me here that I am screwing up. Thanks!

Consider:  namespace WindowsApplication1 {     public partial class Form1 : Form     {         public Form1()         {             InitializeComponent();         }          private void button1_Click(object sender, EventArgs e)         {             //int[] val = { 0, 0};             int val;             if (textBox1.Text == "")             {                 MessageBox.Show("Input any no");             }             else             {                 val = Convert.ToInt32(textBox1.Text);                 Thread ot1 = new Thread(new ParameterizedThreadStart(SumData));                 ot1.Start(val);             }         }          private static void ReadData(object state)         {             System.Windows.Forms.Application.Run();         }          void setTextboxText(int result)         {             if (this.InvokeRequired)             {                 this.Invoke(new IntDelegate(SetTextboxTextSafe), new object[] { result });             }             else             {                 SetTextboxTextSafe(result);             }         }          void SetTextboxTextSafe(int result)         {             label1.Text = result.ToString();         }          private static void SumData(object state)         {             int result;             //int[] icount = (int[])state;             int icount = (int)state;              for (int i = icount; i > 0; i--)             {                 result += i;                 System.Threading.Thread.Sleep(1000);             }             setTextboxText(result);         }          delegate void IntDelegate(int result);          private void button2_Click(object sender, EventArgs e)         {             Application.Exit();         }     } }   Why is this error occurring?     An object reference is required for the nonstatic field, method, or property 'WindowsApplication1.Form1.setTextboxText(int)


I am trying to initialize a list, but then I have to change each cell in said list. I did:  matrix = [[[0] * len(t[0])] * len(t[0])]   But when trying to change one cell it changes the entire column of the matrix. Why is this?

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?