How do I define and initialize a variable that generates random integers from 2 to 20 inclusive?

I need to create two different dice in Java. The first one (dice1) has random integer values from 1 to 10 inclusive. The second dice (dice2) should have even numbers from 2 to 20 inclusive. I was able to successfully code for dice1 but cannot figure out how to declare and initialize dice2. Below is the code I wrote for dice1. How would I go about coding for dice 2? int dice1 = (int)Math.floor(Math.random()*(10-1+1)+1);


How to set PDF compatibility to "Acrobat 5 (PDF 1.4)"

My Master's Thesis is going to be printed at a printing office, and they have requested the compatibility of the PDF to be "Acrobat 5 (PDF 1.4)". How can this be defined?


Calling the camera from another Activity

I have my main Activity in which I have a few Buttons. One of them is supposed to open the Camera. To make it cleaner I am using View.onClick(), so I will just have the Button on the main Activity and the rest will be managed by another other class (Camactivity).  In my main Activity :    Button btnrep = (Button)findViewById(R.id.button3);   btnrep.setOnClickListener(new Camactivity(this));   and in my   public class Camactivity extends Activity implements View.OnClickListener      private File imageFile;     private Context appContext;      public MainActivity_1(Context context)     {         appContext = context;     }       @Override     public void onClick(View view) {                  Intent intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);//use intent and pass in mediastore                 //mediastore is a databases where image and video are stores and link                  imageFile = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "BreedingGround.bmp");         /*link to a directory - pass in directory where you want to save the pictures and names of the file*/                   Uri tempuri = Uri.fromFile(imageFile);//Convert imageFile to a Uri                 intent.putExtra(android.provider.MediaStore.EXTRA_OUTPUT, tempuri);//location where u want the image file to be save after taking photo                 intent.putExtra(android.provider.MediaStore.EXTRA_VIDEO_QUALITY, 1);//quality of out image, 1 means high quality image                   startActivityForResult(intent, 0);//Request code 0 to identify who send the request      }   However I am getting a null pointer error at startActivityForResult(intent, 0);   FATAL EXCEPTION: main Process: com.example.mohit.softeng, PID: 22075   java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.pm.PackageManager android.content.Context.getPackageManager()' on a null object reference       at android.content.ContextWrapper.getPackageManager(ContextWrapper.java:97)       at com.example.mohit.softeng.MainActivity_1.onClick(MainActivity_1.java:60)       at android.view.View.performClick(View.java:5697)       at android.widget.TextView.performClick(TextView.java:10826)       at android.view.View$PerformClick.run(View.java:22526)       at android.os.Handler.handleCallback(Handler.java:739)       at android.os.Handler.dispatchMessage(Handler.java:95)       at android.os.Looper.loop(Looper.java:158)       at android.app.ActivityThread.main(ActivityThread.java:7225)       at java.lang.reflect.Method.invoke(Native Method)       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)


Any formulation give a clear view of this?

After reading this  , I have question on how do we know or "see" the sense on the 4th statement, "Hence it is either prime itself, or divisible by another prime greater than $p_n$ " which meant if P is not a prime, it must be a product of higher prime? I start by considering it cannot be any even number, as it contain constitution of "2" which is divisible by 2 which left only odd number but the odd number must be prime number? Also in most of the proof of infinite prime $P=p_1p_2....p_n+1$ , are the proof actually meant P is not divisible by any prime in the list only(excluded higher prime like $p_{n+1}$),by definition from the list of prime use in above formula and definition of prime, P is a new prime?


How do I clear everything (data, viruses) from a thumbdrive?

Say I used some thumbdrive on a public Windows computer and I copy some data to my Ubuntu computer with it. I cannot be completely sure that the Windows computer was clean, and it might have put something onto my thumbdrive. Is there a way to erase everything on a USB-Stick, even MBR viruses and that kind of off-filesystem stuff?


I want to compute the value of  $\sum_{k=1}^{\infty} k^{-k}$.   First i try to check whether this series converges,   \begin{align} \lim_{k \rightarrow \infty} k^{-k} = \lim_{k\rightarrow \infty} e^{-k \log(k)} =0 \end{align} Thus i see that series converges.   But how do we know the exact value of this series?


Proof of identity $F_m F_n + F_{m−1} F_{n−1} = F_{m+n−1}$ for Fibonacci numbers

I'm lost on where to start on this proof:  Using the fact that $A^m A^n = A^{m+n}$ , prove the identity  $F_m F_n + F_{m−1} F_{n−1} = F_{m+n−1}$  I want to use induction starting with n = 1, but would I also have to make m = 1? I haven't done induction with 2 variables before.  or because of $A^m A^n = A^{m+n}$ should I setup the problem as a matrix (in that case what would the columns/rows be)?   I tried doing it mathematically however I think my algebra is wrong so I won't post it here. Am I correct to believe that $F_{m-1} = F_m*-1$ is not the same as $2^{n+1} = 2^n*2$?  Any help would be appreciated, thanks.


Any disadvantages of elastic net over lasso?

What are the disadvantages of using elastic net in comparison to lasso.  I know that the elastic net is able to select groups of variables when they are highly correlated.    It doesn't have the problem of selecting more than $n$ predictors when $p \gg  n$. Whereas lasso saturates when $p \gg n$. When there are highly correlated predictors lasso tends to just pick one predictor out of the group.  When $n \gg p$ and the predictors are correlated, the prediction performance of lasso is smaller than that of ridge.    All these disadvantages of lasso are overcome by the elasic net.   What I don't understand is when should the lasso be then used? Is there any reason to use it when the elastic net performs better than lasso? What are the disadvantages of using elastic net in some cases? In which cases would the lasso be a better choice?


Understanding %CPU while running top command

I am trying to understand what does %CPU means when I run top.  I am seeing %CPU for my application as 400 or 500 most of the times.  Does anyone knows what does this mean?  What number is a high number?     19080 david  20   0 27.9g  24g  12m S   400 19.7 382:31.81 paper_client   lscpu gives me below output:  Architecture:          x86_64 CPU op-mode(s):        32-bit, 64-bit Byte Order:            Little Endian CPU(s):                32 On-line CPU(s) list:   0-31 Thread(s) per core:    2 Core(s) per socket:    8 Socket(s):             2 NUMA node(s):          2 Vendor ID:             GenuineIntel CPU family:            6 Model:                 45 Stepping:              7 CPU MHz:               2599.928 BogoMIPS:              5199.94 Virtualization:        VT-x L1d cache:             32K L1i cache:             32K L2 cache:              256K L3 cache:              20480K NUMA node0 CPU(s):     0,2,4,6,8,10,12,14,16,18,20,22,24,26,28,30 NUMA node1 CPU(s):     1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31


Display PDF with Visualforce using Lightning Experience

Is  post still valid as a solution to download a pdf from third-party site, then displaying it in a Visualforce page?   This is what I'm doing in my code:  Visualforce page  <apex:page controller="pdfDownloadController" sidebar="false" showHeader="false" contentType="application/pdf">     <script>         window.location.href = "data:application/pdf;base64,{!pdf}";     </script> </apex:page>   Apex Class  public class pdfDownloadController {      public String getPdf() {         HttpRequest req = new HttpRequest();         req.setEndpoint('https://www.irs.gov/pub/irs-pdf/fw4.pdf');         req.setMethod('GET');                                    // Make call         Http client = new Http();         HttpResponse rsp = client.send(req);          return rsp.getBody();      }  }   This is what loads when I go to this Visualforce page in lightning:    It doesn't appear to work when I go to classic either.  UPDATE:  As suggested by sfdcfox suggested, I used his method to display the pdf. That didn't work, but I did see these errors in the web console (Firefox):    I tried Chrome got a different browser response:    This what I get in the debug log from the response body. It looks like a pdf:


I am using the RSA Algorithm for encryption/decryption, and in order to decrypt the files you have to deal with some pretty big values. More specifically, things like   P = C^d % n   = 62^65 % 133   Now that is really the only calculations that ill be doing. I have tried using Matt McCutchen's BigInteger Library, but I am getting a lot of compiler errors during linking, such as:  encryption.o(.text+0x187):encryption.cpp: undefined reference to `BigInteger::BigInteger(int)'  encryption.o(.text+0x302):encryption.cpp: undefined reference to `operator<<(std::ostream&, BigInteger const&)'  encryption.o(.text$_ZNK10BigIntegermlERKS_[BigInteger::operator*(BigInteger const&) const]+0x63):encryption.cpp: undefined reference to `BigInteger::multiply(BigInteger const&, BigInteger const&)'   So I was wondering what would be the best way to go about handling the really big integers that come out of the RSA Algorithm.  I heard that a possibility would be to declare your variables as a double long, so...  long long decryptedCharacter;   but I'm not sure exactly how big of an integer that can store.    Well for example, I try to compile and run the following program using dev C++:  #include iostream  #include "bigint\BigIntegerLibrary.hh"  using namespace std;  int main() {     BigInteger a = 65536;     cout << (a * a * a * a * a * a * a * a);     return 0; }   then I get those errors.  Derek, I thought that by including the BigIntegerLibrary.hh file, that the compiler would go through and compile all the necessary files that it will use.  How should I try and compile the program above in order to resolve the linking errors?


bash + how to set variable instead array element

we can build array list of a..z range as the following   example1  list=({a..z}) echo $list echo ${list[*]} a b c d e f g h i j k l m n o p q r s t u v w x y z   but in case we want to set variable in the array as the follwing  var=a list=({$var..z}) echo ${list[*]} {a..z}   we not get the values from a..z as example1  How to set it so we can print all characters of the alphabet?


Calculating required uplink capacity of network switch

Is there any common method (usable in practice) for estimating the uplink capacity of switch based on known number of users connected to this switch and the maximum internet speed they are allowed.   This is an example topology:  core switch ==== aggregation switch ---- access switch 1 ---- 10 users                                   |----- access switch 2 ---- 30 users                                   |----- access switch 3 ---- 50 users   I want to find the needed capacity (or maximum traffic in the busiest hour) for the links between aggregation switch and access switches 1, 2 and 3. I know they will be allowed to have maximum internet speed of 50 Mbit/s and no transfer between users.  In the worst case they will all download at 50 Mbit/s, so 50 users * 50Mbits/s = 2500Mbit/s but this case will almost never happen as the traffic comes on bursts and it will be waste of resources.   So I need a general method, best practices or any guide for this job. All I find in the Internet is theory with almost scientific value, but no information how they do it in IPSs and telecommunication companies in practice.


I was trying to install viber using .deb package : dpkg --install viber.deb and got the following error : Selecting previously unselected package viber. (Reading database ... 373332 files and directories currently installed.) Preparing to unpack viber.deb ... Unpacking viber (12.0.0.7) ... dpkg: dependency problems prevent configuration of viber:  viber depends on libssl1.0.0; however:   Package libssl1.0.0:amd64 is not installed.  dpkg: error processing package viber (--install):  dependency problems - leaving unconfigured Processing triggers for gnome-menus (3.32.0-1ubuntu1) ... Processing triggers for desktop-file-utils (0.23-4ubuntu1) ... Processing triggers for mime-support (3.60ubuntu1) ... Processing triggers for bamfdaemon (0.5.3+18.04.20180207.2-0ubuntu1) ... Rebuilding /usr/share/applications/bamf-2.index... Processing triggers for hicolor-icon-theme (0.17-2) ... Errors were encountered while processing:  viber  Since then I haven't been able to do anything using apt. I always get: sudo apt install viber                     Reading package lists... Done Building dependency tree        Reading state information... Done viber is already the newest version (12.0.0.7). You might want to run 'apt --fix-broken install' to correct these. The following packages have unmet dependencies:  viber : Depends: libssl1.0.0 but it is not installable E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).  The problem is, when I try: apt --fix-broken install  I get: Reading package lists... Done Building dependency tree        Reading state information... Done Correcting dependencies... Done The following packages will be REMOVED:   viber 0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded. 1 not fully installed or removed. After this operation, 346 GB disk space will be freed. Do you want to continue? [Y/n]  Is it normal that it says my whole disk space is going to be freed? Otherwise what should I do to fix this?


Logistic regression in R ; glm.fit: fitted probabilities numerically 0 or 1 occurred


Wrong position xticklabels with un-intact data

The following MWE making a plot by pgfplots shows xticktables in wrong position along the x-axis. I think this is caused by lost data. So, is there a approach to make these xticktables in right position regardless lost data.   PS: the given soluntion above   does not solve my problem. I tried by adding xtick=data, the lost data still causes wrong position of xticklable from "c".  \documentclass{article} \usepackage{pgfplots} \pgfplotsset{compat=newest} \usepackage{filecontents}   \begin{document} \begin{filecontents}{test.dat}  id,note,a 1,a,1 2,b,4 3,c, 4,d,16 5,e,25 \end{filecontents}  \begin{tikzpicture} \begin{axis}[ table/col sep=comma, title={example}, xlabel=id, ylabel={$data$}, xticklabel style={rotate=90}, xticklabels from table={test.dat}{note}, % xticklabels={a,b,c,d,e} % I also tried this, but still fail. ] \addplot [blue,mark=*] table[x=id,y=a] {test.dat}; \end{axis} \end{tikzpicture}  \end{document}


An irreducible polynomial in a subfield of $\mathbb{C}$ has no multiple roots in $\mathbb{C}$

Let $K\subset \mathbb{C}$ be a subfield and $f\in K[t]$ an irreducible polynomial. Show that $f$ has no multiple roots in $\mathbb{C}$.   If I understand this question correctly, I must show that there is no $a \in \mathbb{C}$ such that $(t-a)^n|f$ in $F[t]$ with $n>1$. So suppose $(t-a)^2|f$ and $f=(t-a)^2h$. Then we have $f'=2(t-a)h+(t-a)^2h' \Rightarrow (t-a)|f'$ so $\gcd(f,f'$) is not constant. Therefore $f$ is divisible by some square of non-constant polynomial in $F[t]$, which is a contradiction. Is my argument correct? Thank you.


Jquery: addClass to dynamic element that doesn't exist on page load

I'm using Icegram (an "exit intent" modal popup plugin) on a page. We have click-to-call links on the page, and the problem is that anytime someone clicks to call, the browser sees it as leaving the page so our exit intent popup shows while people try to call, which is definitely not what we want.  So, I've tried adding a jQuery function to the call links, like this:    8888888888

      But no matter what I do, the "hide-icegram" class does NOT get applied to the icegram popup, so it stays visible.  I noticed that
 is inserted in the page only when it's  activated. So I'm wondering if the addClass isn't working because it's looking for the "icegram-popup" div, but it doesn't exist on page load so maybe that's the issue?  I just want the "hide-icegram" class applied to
 anytime someone clicks the call links. Any ideas?


Automatic grammar fixing in questions and answers

I would like to add automatic grammar fix when posting questions or answers.  For example, automatically capitalizes i's, when the letter is used as the word I.  This is something seriously frustrating as someone who has been spending a lot of time editing posts, the majority of which have i's which are not correctly capitalized.  Surely having the i's automatically capitalized where necessary is a simple fix to make?  Please note, that unlike , the request here is not for a spell checker that just mark incorrect words (like some browsers are doing already) but to have it done automatically, without me having to do anything.


How could I extract all peaks from a DEM (large mountainous area) using GRASS?   Peak means something like: a pixel which is sourrounded by other pixels with smaller elevation numbers in a area arround the "peak-pixel" of about 100m.


Ctrl + Alt +  doesn't work on non-US (f.x. German, Danish) keyboard layout

I have just recently moved from MS windows to Linux, and it is great; but there is one thing that really bugs me, and that is the use of Ctrl+Alt+key instead of using Alt Gr+key.  When I program, it irritates me that often used buttons like curly-braces and square-brackets are not easily accessed through Ctrl+Alt+key. How do I change the behavior of Ctrl+Alt+key to do the same as Alt Gr+key?  As mentioned earlier, my keyboard has a Danish layout.


How do i get content from an iframe using jquery?

I inserted an iframe tag to my HTML page and i want to hide some contents in that iframe. This iframe content is from different origin. I used $("#iFrame").contents() but it is not working. Is this a issue related with browser?


can't boot into ubuntu please help my files are all gone

I have a Windows 8 based Sony Vaio laptop.  Recently I installed Ubuntu 14.04 LTS on my laptop alongside windows, now I can't login into Ubuntu anymore. The boot menu directly boots into Windows 8 and doesn't show the grub menu.  All my files are on Ubuntu, how can I access it or at least how can I retrieve them?


I have a web server that I want to map a drive to it. I want to do this in a .bat file. Pseudo ->   Check if a drive at an ip address has been mapped to a local drive.  If it has then progress with a reference to the drive If not map to a local drive and then progress with a reference to the drive  Is this possible and if so how can I achieve it?


There is context menu entry on cmd, "Run as Administrator", that opens UAC window and launches cmd as Administrator.  How can I open a program as Administrator in command line? I've read about runas but it requires /user option when context menu entry doesn't require it.  How can I open a program as Administrator in command line without specifying user name? Like context menu entry does.


I have written a paper which I have titled in the format Adjective1 and Adjective2 Noun1 and Noun2. Both adjectives modify only Noun1. The two nouns are inherently not related and the point of the paper is to show the relation of Noun1 with Noun2, but Noun1 needs to be mentioned first because it is given more focus. An example of a phrase in this format would be Blue and Red Apples and Planets. Or Short and Tall Buildings and Cats. Is this kind of phrasing grammatically incorrect, unnatural or confusing? How can it be rephrased? I can probably rephrase it into Blue and Red Apples and their connections to Planets, but using the phrase "and their connection" is rare in my field since papers whose titles are lists are already implied to be about the items on the lists and their connection with each other. It is not uncommon, for example, for papers to have a title like Apples, Buildings and Cats.


How to fix textarea height as per text using HTML and Jquery

I need one help. I need to fix the the textarea height as per the content written inside it. I am explaining my code below.          <link rel="stylesheet" href="lib/style.css">
Hello
     <textarea id="textarea-container">     Line 1     Line 2     Line 3     Line 4     ccccccccccccccccccccc </textarea>        Here some text are present inside the textarea and its scrolling. I need here the text area height will expand as per the content present inside it not more than that and it never scroll.


Setting zIndex of CartoDB.js layer on top of Google Map's GroundOverlay?

I am trying to combine the  with . It appears both APIs are displaying their layers correctly.   However, the ground overlay is always displayed on top. I would like to see the positions from the CartoDB viz layer to appear on top of the ground overlay. Any suggestions?


What font does Windows use in dialog boxes?

I was wondering what font Windows uses in dialog boxes, such as this one:


How to call a deriving class operator()?

I want create an expression structure, to calculate value (by calling operator().   expr - base expression class, it should work like result = expression(100500). const_value - struct returns constant value. argument - returns it's argument (== function id). e_add, prod, sub, ... - different functions.  Why code calls base class operator(), but ignore derived structires?  output:  EXPR::operator() called EXPR::operator() called  201000 const_value 1 called arg = 100 1   Full source code:  #include <iostream> #include <cmath>  using namespace std;  struct expr {     virtual double operator()(double) {         cerr << "EXPR::operator() called\n";         return 100500;     }; };  struct const_value : public expr {     double _value;     const_value (double value = 0): _value(value) {};     double operator()(double arg = 0) override {         cout << "const_value " << _value << " called arg = " << arg << '\n';         return _value;     }; };  #define make_bin_op(_op_name, _op) struct e_##_op_name : public expr {     \     expr _left;                                                            \     expr _right;                                                           \     e_##_op_name(expr left, expr right): _left(left), _right(right) {};    \     double operator()(double arg) override {                               \         return _left(arg) _op _right(arg);                                 \     };                                                                     \ }  make_bin_op(add,  +);  #undef make_bin_op  int main() {     const_value c1{1};     e_add e{c1, c1};      cout << e(100) << endl;     cout << c1(100) << endl;      return 0; }


I am using Blender 2.66a a nVidia GT 520 and Ubuntu 13.10. I wanted to enable GPU rendering. But in the System Panel there is no 'CUDA' Option.  I know that this Card supports CUDA, because I have tested it on Windows 7 (dual- boot) too and it worked. I installed the proprietary GPU driver using  sudo apt-get install nvidia-current   Any ideas why it doesnt work? Thanks in the preface


Are constant C expressions evaluated at compile time or at runtime?

If I write a #define that performs an operation using other preprocessor constants, is the final value computed each time the macro appears at runtime? Does this depend on optimizations in the compiler, or is it covered under a standard?  Example:  #define EXTERNAL_CLOCK_FREQUENCY    32768 #define TIMER_1_S                   EXTERNAL_CLOCK_FREQUENCY #define TIMER_100_MS                TIMERB_1_S / 10   Will the operation 32768 / 10 occur at runtime every time I use the TIMER_100_MS macro?  I would like to avoid the following:  #define EXTERNAL_CLOCK_FREQUENCY    32768 #define TIMER_1_S                   EXTERNAL_CLOCK_FREQUENCY #define TIMER_100_MS                3276     Summary  A compiler is required to be able to evaluate constant integral expressions because they are necessary for calculating things like array sizes at compile time. However, the standard only says they "can" -- not "must" -- do so. Therefore, only a brain-dead compiler would not evaluate a constant integral expressions at compile time, but a simple check of the assembly output for an unconventional compiler would verify each case.


Is it possible to enable adress bar in Nautilus on Ubuntu 18.04?

I stopped to use Ubuntu a few years ago. If I Install the new version 18.04, will it be possible to leave Nautilus with address bar instead path bar? Does dconf still work for such tasks on new Ubuntu Bionic Beaver? Nautilus open terminal it's out of Ubuntu 18.04 , because was a good tool?


On my ubuntu server, an unknown process is consuming all 16 of 40 cores. It starts again after I kill it.   Script: ld-linux-x86-64-so.2 Full command $HOME/.ttp/a/stak/ld-linux-x86-64-so.2 --library-path $HOME/.ttp/a/stak/   Here is output of my htop command.     I tried to kill it but it starts again. It is slowing down my server. Kindly guide me how to permanently stop this process.


What are these rays that appear in photograph of sun?

In many images of light emitting objects we see such rays. Why do they appear ? What is the math behind their number and direction?


Has "Killer Game Programming in Java" by Andrew Davison been rendered useless? What new tutorial should I follow?

Its pathetic how it was created in 2005 not so long ago when the Java 3D 1.31 API was released. Now after downloading the source code off the books website and implementing it onto my work-space it cant run. (The 3D Shooter Ch. 23) I downloaded Java 3D 1.5 API, installed it- went back to my source code and javax.media ect.., and EVERY imported class within the game simply couldn't be resolved... they are all outdated..   Please do not say how its meant for a positive curvature in your game development skills. No ~ I got the book to understand how to code 3D textures/particle systems/games. Without seeing results how can I learn?  If there is still hope for this book please tell me. Otherwise what other books match this one in Game Programming? This one was very well organized, documented and long. I am not looking for a 3D game prog. book on Java. Rather one that has the same reputation as this one but is a bit newer..


In BvS, did Flash show Batman a possible future or just his nightmares come true?

The scene in  where Batman sees future Flash has prompted a lot of debate online, but there's a question I haven't seen addressed yet. The "nightmare" that Batman had of a Superman gone bad would seem to be the fruition of all his concerns regarding the Kryptonian. Assuming that Flash caused the nightmare, it begs the question of whether that was an actual glimpse into the future (presumably the one that THAT Flash came from)... or if it was a just a nightmare Flash used to get his attention for the message he gave. I know there are lot of extra scenes in the Ultimate Edition cut, but I haven't seen that cut yet.  Has Zack Snyder or anyone involved with the production of "Batman vs. Superman" commented on whether this was an actual glimpse into a possible future?


How to check Internet Speed via Terminal?

Instead of going to sites like , I want to check my current Internet speed from the terminal on Ubuntu. How can I do it?


Counting occurences of a character in an excel spreadsheet

Feel silly asking this question, but I need some help!   I want to count how many * appear in a range of 5 cells.  The cells will range from 0-7 * each.   I was thinking of using the =COUNTIF(A2:A:6,"*") function, but if the cell has more than one *, it doesn't work. Any idea what function I should use or how I can modify my COUNTIF function to make it work?  Thanks in advance.


The 'Software Updater' does not have enough disk space on /boot drive

The 'Software Updater' states my computer does not have enough disk space on the /boot drive. It instructed me to free up enough space, but I do not have permission to delete any files. What should I do?  Also, deleting general files (pics, videos, etc.) off my hard drive does not help.


I am using Ubuntu 13.04 and as a shell, Gnome 3. After I have updated Ubuntu to 13.04, the Print Screen Button does nothing, though in the System Settings at the Keyboard Shortcuts, in the Screenshot section I have the following:    I have even tried to make my custom shortcut to gnome-screenshot, but it still doesn't work. The only way I can take a screenshot is by pressing Alt+F2 and then typing "gnome-screenshot", or typing this in the terminal. It is weird that in Unity the Print Screen button works.


$F$ is a closed set in $\mathbb{R}$, Then $\frac{d(x+y, F)}{|y|}\rightarrow 0, |y|\rightarrow 0$ for each $x\in F$.

$F$ is a closed set in $\mathbb{R}$ and denote $d(y,F)=\inf\{|y-z|: z\in F\}.$ Then $$\frac{d(x+y, F)}{|y|}\rightarrow 0, |y|\rightarrow 0$$ for a.e $x\in F$.  I have no idea even though the hint says that the Lebesgue identity is useful.


Choose $x_0\in (0,\pi)$ arbitrarily, and define a sequence $x_n$ iteratively by $x_n=\sin(x_{n-1})$ for each $n\ge 1$. Show that $\lim_{n\to\infty} \sqrt{n}\cdot x_n =\sqrt{3}$.  I am not able to solve this. Not even a single idea which can help came to my mind. So any hint or solution.


Knowing pre-encryption data, can we find the private key CryptoLocker used?

One of our users seems to have been hit by . As a result, he has a hard drive full of encrypted files. The ransom-ware claims to have used public key encryption on  the files.  If we know exact contents of some of the files prior to them being encrypted, would it be feasible to use those files to discover the private key?


Emails from my domain getting blocked at all other domains

Recently I tried to set up a new email server using iRedMail on Lubuntu.  The mail server workes very well when email conversation is in the same domain.  But when a user tries to send email to some of the most popular domains like gmail, hotmail or yahoo; all the emails are blocked.  I tried to send an email to my gmail account, this is error response I got.     host gmail-smtp-in.l.google.com[74.125.130.27] said: 550-5.7.1   [XX.XX.XX.XX      12] Our system has detected that this message is   550-5.7.1 likely unsolicited mail. To reduce the amount of spam sent   to Gmail, 550-5.7.1 this message has been blocked. Please visit   550-5.7.1    for   550 5.7.1 more information. g12si14338274pat.29 - gsmtp (in reply to   end of DATA command)   The XX.XX.XX.XX part is my IP.  Latter I found that my ip is added to black list at . I requested them to remove my IP. They accepted my request. It also suggested to activate the smtp authentication.   But it was already set to yes as given below.  smtpd_sasl_auth_enable = yes   After a few hours, I again tried to send a mail to my gmail account, again same msg is replied. When I check the spamhaus database, my ip is also there.  Please help.


Evaluating the quotient of Dedekind Eta function

This expression I found in some research paper, which connects quotient of Dedekind eta function and ray class field of conductor N, which in turn gives the value of j-invariants.  For $K=\mathbb Q(i)$ and N=3$ (conductor), the discriminant of the order is -36.  Now, $ j_{1,3}(\tau)=\dfrac{\eta(\tau)^{12}}{\eta(3\tau)^{12}}$, where $\tau=i$.  I evaluated this expression in Pari/Gp, and I got the answer in decimals which I found wrong, if some one knows their reply will be of great help


I will be traveling to Korea in a few months with a layover in Shanghai. Looking over the visa requirements for US citizens in Wikipedia, it says I do not need a visa if I am traveling to a third country in this case Korea. Because it is China and all, I want to confirm that I do not need a visa for China in this situation. Should I even go a step further to confirm this rule by calling the consulate? I don't want to get there and find out I can't continue my trip because of something I overlooked.  Edit: I am a US Citizen and my layover is less than 4 hours.


How to upgrade ubuntu from 12.10 to 13.4 without lossing anything?

well title says all most everything. I am using ubuntu 12.10. Installed using windows installer. Is there anyway to upgrade it? Any how much data i will lose? I have installed some softwares and there is some docs.


Deleted sources.list.d and sources.list in "/etc/apt" accidentally

While debugging some errors, I accidentally deleted sources.list.d and sources.list at "/etc/apt". Now, I cannot install or do anything just because those files do not exist. How can I get those files back? Is there any way to recover them? I have a copy of the context of the sources.list. I would greatly appreciate your help.


If I have something like this:  root        27  0.0  0.0      0     0 ?        S    04:06   0:00 [migration/3] root        28  0.0  0.0      0     0 ?        S    04:06   0:00 [ksoftirqd/3] root        30  0.0  0.0      0     0 ?        S<   04:06   0:00 [kworker/3:0H]   What can these numbers(/3 or /3:0H) can tell me?  man ps, man top - nothing said about this.


Proving that, $|f'(x)-f'(y)|\le k|x-y| \implies (f'(x))^2< 2 kf(x) $

Let $f:\Bbb R\to (0,\infty)$ be a differentiable function such that for some constant $k$ we have, $$|f'(x)-f'(y)|\le k|x-y|$$   for all $x,y \in\Bbb R.$ Then prove that, $$(f'(x))^2<2 kf(x).$$   Due to lack of arguments I could not proof this inequality. But rather I proved that is true for the particular function,   $$f(x) =\cos^2(x)+1\implies f'(x) = -\sin(2x).$$ And we readily have,$$|\sin(2x)-\sin(2y)| = \left|\int_{2x}^{2y}\cos t dt\right|\le 2|x-y|$$ as well   $$(f'(x))^2 = 4 \sin^2 x\cos^2x < 4(\cos^2x +1) = 4f(x).$$  It is also true for the function $x\mapsto \sin^2x +1.$   From these example I don't see how to prove the general case. Any hint will be welcome.


I am looking for introductions and reviews (papers or books) on the possible observation and the nature of dark matter. This  seems to be a good start, but I would be grateful for any other recommendations  that are accessible to people with knowledge of physics at the undergraduate level.


Understanding the term "double roots" of a quadratic equation

We know that when a quadratic equation $ ax^2 + bx + c = 0 $ has zero discriminant value, then the quadratic equation has only "one root". But why do some mathematician call it "double root" and also that the equation still has two roots, but their roots are double. When we draw the equation in the coordinate plane, we can see that the graph of the equation will just touch the $ x $-axis at only one point. The second question is: We know that the sum of the roots of a quadratic equation $ ax^2 + bx + c = 0 $ is $ -\dfrac{b}{a} $. But when the discriminant of that equation is zero, the sum is also $ -\dfrac{b}{a} $. It doesn't make sense. For example, if we have quadratic equation $ x^2 + 4x + 4 = 0 $, we can factor it as $ \left(x + 2\right)^2 = 0 $ and so $ x = -2 $. Thus, the sum is just $ -2 $. But with "sum of the roots" formula, the sum is $ -4 $. Which one is correct? Is this the reason we call it double root? Thanks in advance :)


Struggling with a Bayes theorem/conditional probability question

The question:  You are playing a card game where the dealer selects three cards from a playing deck; 1 red and two black. The dealer shuffles the three cards and lays them face down next to each other, so that only he knows the position of the red card. He then asks you to guess where the red card is; but he does not turn over your selected card. You win the game if you guess correctly which card is the red card. After your choice of card is made, the dealer turns over one of the cards you did not select, which is a black card (every time the game is played, the card that the dealer will turn over at this stage of the game is a black card). Now the dealer asks if you would like to change your mind. Are you better to change your mind, stick to your first selection, or doesn't it matter? Your answer must be fully justified with mathematical working. Hint: To get a feel for this question, think about the case where there are many cards (say 1000), but still only 1 red card and the dealer overturns all but 2 (998 cards).  --  Now I'm confused with how to approach this problem. I have a feeling that you need to gather the probabilities from before the event of the dealer putting the cards face down, and then after choosing a card and having to choose whether or not to change your mind.  Can anyone help me on approaching this question? Would be very appreciative. Thanks.


How can you include a script defined in a variable?

In my .bash_profile file, I have this, which works fine to execute that script in the same process that I'm launching my shell...  . ~/Code/iOS/CommunityDemo/APIMocker/mockutil.sh   I realized for part of that script, I need the path where it resides to be used within it.  Normally, you'd just do this...  MOCKUTIL_PATH=$(dirname "$0")   However, since I'm not spawning the script into its own process, but rather including the script in my profile script, the above understandably yields /bin, not ~/Code/iOS/CommunityDemo/APIMocker as I need.  "No worries!" I figured... I'd just export the path from within my profile, like this...  export MOCKUTIL_PATH="~/Code/iOS/CommunityDemo/APIMocker" . ${MOCKUTIL_PATH}/mockutil.sh   but I'm getting this...  bash: ~/Code/iOS/CommunityDemo/APIMocker/mockutil.sh: No such file or directory   Now I can just do this, but I really hate redundancy!  export MOCKUTIL_PATH="~/Code/iOS/CommunityDemo/APIMocker" . ~/Code/iOS/CommunityDemo/APIMocker/mockutil.sh   So... is there a way to define that path once, then use that definition in the source (.) command?


Can teleportation save you from fall damage?

I am surprised that I wasn't able to find this question asked before, but I could see it used as quite an epic showing:  The old lady brings your group over to the mountain base filled with sharp cliffs, jagged rocks, and a path no wider than your foot. The roaring waterfall makes the air crisp, clean, and humid as she stops by a sign adorned with a bell and a rope, looping all the way up the mountain. Turning to your group with a kind smile, the guide pulls the rope and stands in wait. "Well, aren't you going to take us to him?" one of the players exclaim, annoyed at this old hag's smugness. Just as soon as the words escaped their mouth the bell rings, causing the granny's wrinkled face to beam with a smile.* "Oh, he's on his way sonny," She says pointing her knotted cane towards the top of the waterfall. As your party looks, there is a man falling what must be 1000 ft straight into the mouth of the waterfall, finally getting swallowed by the mist below. A second later, the man you have been searching for, the man who jumped down the waterfall, emerges from behind the waterfall, dry and unscathed.  Now though this seems quite epic, the way that the guy defied death was by using a teleporting spell when he was covered in the mist to reappear on the rock behind the waterfall. From what I understand , teleportation spells do not conserve momentum, so his falling speed would go from 20d6 damage to 1ft no damage. Is this truly how powerful teleportation spells can be?


How to solve java.lang.NullPointerException error?

When I run my Java program, it gives me an error on this line   compiler.getTask(null, null, new DiagnosticCollector<JavaFileObject>(), null, null, compilationUnits);   Error I am getting is:  Exception in thread "main" java.lang.NullPointerException     at AnotherClassLoader.loadClass(test.java:58)     at test.main(test.java:30)     at Main.main(Main.java:68)   Can you please tell me how can I solve this error?


Apache Reverse Proxy redirect with assets folder in another path

I'm using Apache2 to perform Reverse Proxy for my tomcat.  my domain name is  to be redirected to   proxy is ok but tomcat is having an asset folder located in the root folder ()  while loading my dev.domain.com page I have a 404 Error for every assets elements to be displayed. Here is my VirtualHost configuration:  <VirtualHost *:443>      ServerAdmin webmaster@localhost      proxyRequests Off     SSLProxyEngine on      ErrorLog ${APACHE_LOG_DIR}/error.log     CustomLog ${APACHE_LOG_DIR}/access.log combined      ServerName dev.domain.com      ProxyPass / http://127.0.0.1:8080/MyApp/     ProxyPassReverse / http://127.0.0.1:8080/MyApp/      SSLCertificateFile ....  </VirtualHost>   it seems that everything which is not in the MyApp folder is not correctly redirected, do you know I can do that ?


Let $A$ and $B$ rings,  $f: A \to B$  is a surjective homomorphism. Then $f(\operatorname{rad}A) \subset \operatorname{rad}B$ and construct an example where the inclusion is strict.   By $\operatorname{rad}A$ denote the Jacobson radical of $A$, i.e. the intersection of all maximal ideals of $A$.  But how can I prove this ? If $x \in f(\operatorname{rad}A)$ then there exist $y \in \operatorname{rad}A$ such that $f(x)=y$ and then how can I use the surjectivity of $f$ ?  Could someone help me do this please. Thanks for your time and help.


Google Apps from account for canned response

Is there a way to change the “from” name/email address on a canned response auto responder?  I have one account setup with a nickname and a filter with a canned response (an ex employee), but when the canned response is sent, it comes from currentuser+canned.response@domain.com.  Is there any way to make it come from the regular nickname address?  Or even from the regular account address instead of the canned email address?


Easy Stats Question: Sampling a bag of 457 marbles,

I have a bag of 457 marbles, 111 of which are black, and 346 are white. How many marbles do I need to remove from the bag (without replacement) to be 95% certain that I get at least one black marble?  I'm not looking for a specific answer - I want to understand how to solve problems like this. TIA!


proof - if $x^2 + y^2 + z^2 = 2xyz$ then $x = y = z = 0$

Well, I have been trying to prove that:  $$x^2 + y^2 + z^2 = 2xyz \implies x = y = z = 0$$  and have made little progress. Till now, I have only been able to prove that if this is to happen then $x$, $y$ and $z$ must be even. I am explaining how I arrived to this result but don't know how to proceed further or even figuring this out would make sense.  If $x^2 + y^2 + z^2 = 2xyz$, then at least one of $x$, $y$ or $z$ must be a multiple of 2. Let that one number be x and now $2|x$. Also let $x = 2a$.Then, $4a^2 + y^2 + z^2 = 4ayz$.   Now assume that one of $y$ or $z$ is odd. So the other must be odd as well as odd and odd add upto even and we need an even number to make the equality true. But it can be proved that the sum of squares of two odd numbers is never a multiple of $4$. Then the LHS would no longer be a multiple of 4 ($4a^2$ is a multiple of $4$ but $y^2 + z^2$ isn't) while the RHS would be. This is a contradition. Hence, $y$ and $z$ both are even. That's what I have been able to prove till now and still don't know if that is useful.   Please help if you have an answer.


Why does increasing concentration of extracellular sodium have no effect on electrical gradient of potassium?

I learnt that the permeability of an ion across the membrane contributes to the membrane potential as much as(or even more than) its concentration and electrical gradients. And so far I've made peace with the fact that Sodium, having a very low permeability, doesn't contribute much (through its own movement) to membrane potential despite having a high electrochemical gradient directed towards the cell's interior. Now, the confusing thing is that, if I imagine dumping some sodium ions (with their positive charge) on the cell's exterior, this would affect the electrical gradient of potassium (and in fact other ions)--because more positivity is recorded externally-- making potassium in particular less "ready" to diffuse out of the cell. The result of which would be a depression (that is a more negative value ) of the resting membrane potential. If potassium's extracellular concentration were increased instead, a similar effect would be observed. What exactly is wrong with this reasoning? I'm putting this forward because my Professor mentioned only extracellular potassium ion as having an effect on membrane's resting potential.


what should be there in refresh plan in saleforce

I want a document of a Refresh plan for in saleforce . Can someone share, let me know what exactly would need to be in there.   Please let me know the checklist what all should this document have


Creating json from string captured with text.match

Dynamic creation of object from string  I have the string {"person":"me" ,"age":"30"} embedded in a text.  I extract it from the text using    text.match(/{.*}/);   I want to be able to use the object.keys and object.values methods  to get keys to create menus dynamically and return the values based on menu selection.   It appears that I need to be able to create an object dynamically. I would like to do it without having to loop through the string. Is there any function or method that can take the result of text.match as input and give me json that can be used with object.keys and object.values etc.


exception in thread awt-eventqueue-0 java.lang.nullpointerexception error for checkbox in jtable

I have a JTable, which was built in Netbeans, with a column that is set to Boolean value. To obtain the rows that were checked, the user has to click the 'Reorder' button which checks the table to see which rows were selected.  The code that is supposed to find the stock id based on if the JCheckBox is checked is as follows:     for(int i=0; i<jTable2.getModel().getRowCount(); i++){       boolean check = (Boolean) jTable2.getModel().getValueAt(i, 4);       if(check){             Object o = (Object)model2.getValueAt(i, 0);             int stockID = Integer.parseInt(o.toString());             System.out.println(stockID);         }     }       Note that model2 is jTable2.getModel(). The above code throws the NullPointerException. If I print out    jTable2.getModel().getRowCount()   I will get the accurate row count. If I print out   boolean check = (Boolean) jTable2.getModel().getValueAt(2, 4)   I will get the accurate boolean value. But it throws the exception when I use the code in a for loop.


I am wondering if there is any way to add a curve to this ōdachi I made without having to go into the mesh and add it manually, since it'll be very painstakingly difficult to do it manually.  Thank you in advance!


Finding center of $GL_n(\Bbb R)$ using elementary matrices

I want center of $GL_n(\Bbb R)$.   Artin, in his book Algebra, hints that, 'You are asked to determine the invertible matrices $A$ that commute with every invertible matrix $B$. Do not test with general matrix $B$, test with elementary matrices.'    I know that  and  generate $GL_n(\Bbb R).$ I also see that Row-multiplying transformations (unless all diagonal entries are 1's) and Row-addition transformations (unless all off-diagonal entries are 0's) don not commute with each other, so only elenentary matrix in center is $I$.  What I don't get is:  1. How do we derive from this that $cI$ is in center for any $c\in \Bbb R$? (I can see $cI$ in center, but, it did not click me, because I thought this way: since center is subgroup, $\langle I\rangle$ is in center, but $\langle I\rangle=\{I\}$. Where did I not think through?)  2. No other matrix is in center?


Evaluating $\int \frac{\sin x}{\sin 4x}\mathrm dx$

$$\int \frac{\sin x}{\sin 4x}\mathrm dx$$ I have tried to do this by expanding $\sin 4x$ but it was worthless.


How do I connect to a network share via the Windows Command Prompt?

Is there any way to connect to a network share via cmd.exe?


I can use sudo but I can't use su due to a password Authentication failure, shouldn't both be the same password?

when I try using a command with sudo everything works fine, however, if I want to log in as the superuser using su it doesn't let me. Why?


I am fairly new to the machine learning, and I have been going over all the great posts about cross-validation today and I have a question regarding PCA and cross-validation, I don't have enough points to comment on the  so I thought maybe I should post a new question.  My understanding is the most correct procedure is the following which I saw in an earlier :  for each fold:     split data     conduct PCA on the 90% used for training     pick the number of components     fit linear regression     predict the 10% held out end   My main question is, if I want to do eigenfaces with PCA and SVM I would split up my set of images into my training and validation sets, and then apply the PCA to each new split in my cross-validation and optimization?  My confusion comes because I was following an example on  where they divide the data, and then proceed to caluclate the PCA for the split data. Next, they run  which I understand is doing a cross-validation to tune the parameters. Does this tuning introduce a bias because it preprocessed the data or is it okay for some reason? I have attached the relevant sections of the example below.  ############################################################################### # Split into a training set and a test set using a stratified k fold  # split into a training and testing set X_train, X_test, y_train, y_test = train_test_split(     X, y, test_size=0.25)   ############################################################################### # Compute a PCA (eigenfaces) on the face dataset (treated as unlabeled # dataset): unsupervised feature extraction / dimensionality reduction n_components = 150  print("Extracting the top %d eigenfaces from %d faces"       % (n_components, X_train.shape[0])) t0 = time() pca = RandomizedPCA(n_components=n_components, whiten=True).fit(X_train) print("done in %0.3fs" % (time() - t0))  eigenfaces = pca.components_.reshape((n_components, h, w))  print("Projecting the input data on the eigenfaces orthonormal basis") t0 = time() X_train_pca = pca.transform(X_train) X_test_pca = pca.transform(X_test) print("done in %0.3fs" % (time() - t0))   ############################################################################### # Train a SVM classification model  print("Fitting the classifier to the training set") t0 = time() param_grid = {'C': [1e3, 5e3, 1e4, 5e4, 1e5],               'gamma': [0.0001, 0.0005, 0.001, 0.005, 0.01, 0.1], } clf = GridSearchCV(SVC(kernel='rbf', class_weight='auto'), param_grid) clf = clf.fit(X_train_pca, y_train) print("done in %0.3fs" % (time() - t0)) print("Best estimator found by grid search:") print(clf.best_estimator_)


Can we add functionality to the mobile site to view the page in the SE iOS app? It could be through  or a link at the bottom where the download link is.        I really don't care which, but right now there's just no way to do it.


How do you create a python list comprehension of lambdas?

I am trying create a list of lambdas for deferred execution using a list comprehension. The below is a simple example. def func_a(message: str) -> None:     print('a: ' + message)      def func_b(message: str) -> None:     print('b: ' + message)  msg = 'some message' funcs = [func_a, func_b] funcs_w_args = [lambda : func(msg) for func in funcs]  for func in funcs_w_args:     func()  The result is b: some message b: some message  Whereas the desired result should be a: some message b: some message  Where am I going wrong?


So atoms are formed from protons and neutrons, which are formed from quarks.  But where do these quarks come from? What makes them?


How to run application for a set time in shell

If and How is it possible to, in Terminal, to get an application to run for 30 seconds, before being force closed, and echoing the logs of that process?


String comparison is not working when comparing it against object's string in ArrayList

I am trying to compare the string fields of an object that are stored in an ArrayList against input strings. In this case, I have an arraylist - ArrayList<Customer> and I have created several Customer-based objects that only has the name and email fields. I am trying to check for duplicates by checking the inputs against the name and email fields as follows: import java.util.ArrayList;  class Customer     {         private String cName;         private String cEmail;          public Customer(String custName, String custEmail)         {                 this.cName = custName;                 this.cEmail = custEmail;         }          public String getName()         {                 return cName;         }                  public String getEmail()         {                 return cEmail;         }     }  class Main {       public static void main(String args[])     {          ArrayList<Customer> custArr = new ArrayList();          Customer aaa = new Customer ("John Perkins", "john.perkins@mail.com");         Customer bbb = new Customer ("Peh Yan", "peh.yan@mail.com");         Customer ccc = new Customer ("In Koh", "inkoh@mail.com");         custArr.add(aaa);         custArr.add(bbb);         custArr.add(ccc);          System.out.println("Added in test customers info.");          // Assume these are the inputted values         String name = "in koh";         String email = "inKoh@mail.com";          for(int i=0; i<custArr.size(); i++)         {             // if (custArr.get(i).getName().toLowerCase() == email.toLowerCase() &&             //     custArr.get(i).getEmail().toLowerCase() == email.toLowerCase())              if (custArr.get(i).getEmail().toLowerCase() == email.toLowerCase())             {                 System.out.println("Error! User already exists in the system");             }                      }     }  }  However, the string comparison does not seems to be working unless my input string fields are worded exactly the same as the test data. For example, String name = "in koh" does not works, but if I wrote it as String name = "In Koh", it will works. Need some insights on this as I am pretty sure both getName and getEmail are indeed returning String value


Do Powell and Donovan experience relativistic time dilation, in 'Escape!'?

In the Asimov short story "Escape!" (part of the Susan Calvin series), Powell and Donovan are set by US Robotics to test a spaceship with a hyperspatial drive.  They, at one point claim they have been on the ship for 5 days, whereas I believe Dr Calvin requests 48 hrs to speak to the Brain. I can't perfectly tell if these two times are coterminate or not, but if there are they only travelled at a fraction of c, not faster than it as might be claimed.  So do they experience relativistic time dilation? Or are they subject to other 'physics'?


Should I create a new question when I am offering a bounty?

Yesterday I offered a bounty on my question that is several months old. .  However there have been only 3 more visits since yesterday - so the bounty appears not to be creating more attention.   Should I have asked a new question instead?


Can the shell know what is the character encoding of the terminal?

Some terminals allow you to set their character encoding, but can the shell (or whatever program running on the other end) know what is the character encoding of the terminal?


How to change phone number on Google account

How can I change my phone number on my Google account to have a different phone number with my account.


Is a big switch block unavoidable in C++ due to lack of reflection

Assume I have a hierarchy of classes:  class Shape { };  class Circle : public Shape { }  class Square : public Shape { }  ... hundreds of other shapes continue on...   When given the name of a shape class as a string, I need to instantiate objects of that class.  In java, I can do something like this (pseudo code!)  Shape createShape(String name) {     return new Class.forName(name); }   But in C++, I have to do this:  (pseudo code!)  Shape * createShape(const string &name) {     if (name.compare("Circle") == 0) {           return new Circle();     }     else if (name.compare("Square") == 0) {         return new Square();     }     else if ... //hundreds of else if continues, one for each shape }   Is there any better way in C++ to handle situation like this?


Installing TeXlive 2015, uninstalling TeXlive 2013

I have found many different Q/A regarding installation of various versions of TeXlive and uninstalling (). To be honest, I might have be a bit lazy.. Will see.  To my best knowledge I am running Ubuntu 14.04.4 LTS and I have installed TeXlive 2013, tex --version gives me TeX 3.1415926 (TeX Live 2013/Debian).... I had troubles running the package leadsheets and found some issue thread, that TeXlive 2013 might be missing some features, the exact error is  E: /home/quapka/Development/ZpevnikMladez/tex_songs/template.tex:60 "kernel/command-not-defined"! Control sequence \prop_item:Nn undefined. ...ate_variant:Nn \prop_item:Nn { NV }   Anyway, I decided to install 2015. But I was lazy and just followed  . But did not do the clean up (since this was the first time I was installing TL2015), but I also did not do anything about the previous version (2013). So, after downloading and running sudo ./install-tl I hoped I was done, obviously not. After quick search I've updated PATH, like anywhere I could. I am using zsh, soo, I changed PATH in /etc/environment, ~/.zshrc, ~/.profile. Obviously, running pdflatex outputs This is pdfTeX, Version 3.1415926-2.5-1.40.14 (TeX Live 2013/Debian) and not 2015 version.  It seems 2015 is installed correctly, at least /usr/local/texlive/bin/2015/bin/x86_64-linux/pdflatex outputs This is pdfTeX, Version 3.14159265-2.6-1.40.16 (TeX Live 2015) (preloaded format=pdflatex) , so hey, it's something. Last note, TL 2013 is not in /usr/local/texlive/bin/2013/.. the only thing I could find is in /usr/share/texlive/ (with release notes for 2013 version. In desperate move (it already took me two days, since I lost connection installing TL2015 yesterday) I ran sudo apt-get remove texlive, something was removed but not what I hoped.  My question here is. How to switch to 2015 version? What should I uninstall (or, I worry, uninstall, remove, remove more, install..).  Disclaimer: I know I should be more careful and etc. But I got used to simply run sudo apt-get install/update/upgrade whenever I need to install/update/upgrade something, but all this work because of one package stopped me from being reasonable. If this is dupe of some sort I am happy to delete it and educate myself elsewhere. Thanks!


A geometric reason why the square of the focal length of a hyperbola is equal to the sum of the squares of the axes?

When I teach conics, I give a simple geometric argument for the Pythagorean relation for ellipses. (By "Pythagorean relation" I mean the fact that the square of the focal length $c$ is the difference of the squares of the semimajor and semiminor axes, i.e. $c^2=|a^2-b^2|$ for the ellipse defined by $\frac{x^2}{a^2}+\frac{y^2}{b^2}=1$.) The picture argument goes as follows: just draw the obvious isosceles triangle from the two foci to one of the two points at the end of the minor axis. We see two right triangles; in each, one leg is the focal length $c$ and the other leg is the semiminor axis, while the hypotenuse is the semimajor axis. The result follows from the Pythagorean theorem applied to this right triangle.  But when it comes to the Pythagorean relation for hyperbolas, I can't think of an equally convincing picture to draw. Instead I have to give a rather inelegant algebraic argument for the relation $c^2=a^2+b^2$ (for the hyperbola defined by $\frac{x^2}{a^2}-\frac{y^2}{b^2}=1$, with focal length $c$), directly from the definition of the hyperbola. The messy details are below.*  Now, obviously there is an asymmetry between the argument for the ellipse and the argument for the hyperbola: the ellipse argument is almost trivial and doesn't involve working straight from the locus definition, but the hyperbola argument is tedious and does require working straight from the definition. So, my question:     Is there an equally persuasive picture I could draw to convince high   school students of the Pythagorean relation for hyperbolas -- without having to get technical with points at infinity, say?   The natural triangle to draw is the right triangle with legs from the center to a vertex and from that vertex to an asymptote, which has legs of length $a$ and $b$; but then the problem becomes why the length along the asymptote should be equal to $c$. I doubt there is a purely (Euclidean) geometrical reason because this triangle lies on the asymptote, not on the hyperbola itself; I suspect some sort of limiting procedure will be required.    [*] The tedious algebraic details:     The foci lie at $(\pm c,0)$.   Say $a>b$. Then hyperbola is the locus of points $(x,y)$ such that       $$\left|\sqrt{(x+c)^2+y^2}-\sqrt{(x-c)^2+y^2}\right|=2a$$      Assume for simplicity the expression between the absolute value bars   is positive. (The algebra is even more tedious if we don't make such a   simplifying assumption.) Then moving the right root to the other side   and squaring gives      $$(x+c)^2+y^2=4a^2+(x-c)^2+y^2+4a\sqrt{(x-c)^2+y^2}$$      Simplifying gives      $$xc-a^2=a\sqrt{(x-c)^2+y^2}$$      and upon squaring again we have      $$x^2c^2-2xca^2+a^4=a^2(x^2-2xc+c^2+y^2)=a^2x^2-2xca^2+c^2a^2+a^2y^2$$      which reduces to      $$x^2(c^2-a^2)-y^2a^2=a^2(c^2-a^2)$$      Defining $b^2:=c^2-a^2$ brings the equation into the form   $x^2/a^2+y^2/b^2=1$, and the Pythagorean relation follows from the   definition of $b$.


how to upgrade a single package in debian

I'm currently running debian 8 and I want to upgrade security patches which is provided by debian but problem is that, if I upgrade a single package then it asks to upgrade many packages, as in:  $ apt-get upgrade openssl  The following packages will be upgraded: dpkg dpkg-dev krb5-locales libapache2-mod-php5 libdpkg-perl libfreetype6      libgdk-pixbuf2.0-0 libgdk-pixbuf2.0-common libgssapi-krb5-2 libk5crypto3 libkrb5-3 libkrb5support0 libpng12-0 libssl1.0.0 linux-headers-3.2.0-4-amd64 linux-headers-3.2.0-4-common linux-image-3.2.0-4-amd64 linux-libc-dev ntp php5 php5-cli php5-common php5-   curl php5-readline tzdata unzip virtualbox virtualbox-dkms virtualbox-qt....too many  The following packages have been kept back: acpid anacron apt-xapian-index aptitude aptitude-common aspell-de at at- spi2-core avahi-daemon base-passwd bind9-host binfmt-support bsdutils consolekit cron cryptsetup-bin db5.1-util dbus default-jre default- jre-headless dictionaries-common dmsetup dnsmasq-base dnsutils dovecot-core dovecot-imapd dovecot-pop3d duplicity fakeroot gdebi- core gettext gir1.2-accountsservice-1.0 gir1.2-atspi-2.0 gir1.2-folks-0.6 gir1.2-gck-1 gir1 ....too many   How to skip the above packages?


I've recently seem more and more cases where situation is following: a question with zero upvotes and an one or more correct answers also with zero upvotes. Interesting thing is that often it's indicated in the comment that the answer is correct or it might be correct.   I'm really not sure where is it coming from. Is it because now you cannot un-upvote and answer once a certain time has passed? Or is it that people just don't care about upvoting at all?  Anyway, it transmits kind of a message "you've wasted your time answering that question and no one even cares about it". Which I find it quite demotivating.  Few examples I've stumbled upon myself:


Does character level determine level of items crafted from legendary/set plans?

I've been collecting set and legendary Blacksmith plans as I level my characters, and I teach each of them to Haedrig as I find them. Recently, though, I've started to notice that only a few of these plans are used to make level 70 items, so I'm hesitant to keep collecting them unless I'm playing on a maxed character.  What I want to know is whether or not the level of my character at the time I obtain the plans will affect the level of the item(s) crafted from those plans. (If there are any differences in this regard between legendary and set plans, details would be appreciated.)  If character level does have some effect on what level the crafted item will be, is it possible to get another version of the plan later for a higher-level version of the same item, or am I stuck with the low-level version?


Doing something if connected to particular SSID in Ubuntu

I want to write a bash script that will put off dropbox automatic synchronization if i'm connected to  particular wifi ssid. How can i catch this event: for example i'm working at home and sync is on, if i'm at another place (cafe, work, etc) auto sync is off.  Also I want to do some other task depending on wifi ssid.


How do I lock the desktop screen via command line?

How can I lock my desktop screen from the command line?


1.He has been watching TV.  What does this sentence mean?  Does it mean that the person started watching TV sometime before and still watching it or the person started watching TV sometime before and has stopped watching it? does it mean something else rather than my options?


Are workstation monitors safe to pack in checked luggage?

I need to take my monitors for my workstation with me.  Can I pack them in checked luggage? I have two monitors and they are 13 1/2 inches length by 16 inches width.


A given thermodynamical system has a number of state variables, not all of which are independent. Suppose that we have a system which can be specified by $k+1$ extensive variables: $U,X_1,\cdots,X_k$. We also have $k$ intensive variables which are conjugate to the $k$ extensive variables $X_i$. To what extent are these $2k+1$ variables independent?   For example, we can always express the internal energy in terms of its natural variables: $$U=U(S,V,N_1,\cdots, N_{k-2})$$ But what about in terms of other variables? How about exchanging an extensive variable for its conjugate internal variable, say $T$ in place of $S$: $$U=U(T,V,N_1,\cdots,N_{k-2})?$$ Or perhaps replacing $T$ by some unrelated intensive variable, say $p$ in place of $S$: $$U=U(p,V,N_1,\cdots,N_{k-2})?$$ Will any combination of the remaining thermodynamic variables serve to functionally determine $U$? If not, then what exactly relates these $2k+1$ variables?


Ubuntu gparted doesn't detect windows partition

Please don't mark it duplicate. I have been through the rest of the posts and suggestions!  I am trying to dual boot Windows 7 with Ubuntu or Kali Linux but i am unable to do so.  I have backed up all my data to an external hard drive. So it is safe to work with partitioning.  I have a 500 GB hard drive and installed windows 7 onto a 150GB partition created with windows 7 installer partitioning tool.   I created Kali Linux bootable USB but when i proceed to the manual partitioning tool in the installer, it doesn't detect the Windows partition. It says the 500 GB space is free (unallocated).  I booted into the live kali linux form usb and tried gparted. It gives me the following error.  /dev/sda contains GPT signatures, indicating that it has a GPT table.  However, it does not have a valid fake msdos partition table, as it should.  Perhaps it was corrupted -- possibly by a program that doesn't understand GPT partition tables.  Or perhaps you deleted the GPT table, and are now using an msdos  partition table.  Is this a GPT partition table?   I tried the fdisk and its output is given below.  root@kali:~# fdisk -l  Disk /dev/sda: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors  Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disk identifier: 0xf17f14b8  Device Boot      Start         End      Blocks   Id  System /dev/sda1   *        2048      206847      102400    7  HPFS/NTFS/exFAT /dev/sda2          206848   115345407    57569280    6  FAT16 /dev/sda3       115345408   430327807   157491200    7  HPFS/NTFS/exFAT  Disk /dev/sdb: 7747 MB, 7747397632 bytes 255 heads, 63 sectors/track, 941 cylinders, total 15131636 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000b19d6  Device Boot      Start         End      Blocks   Id  System /dev/sdb1   *          63    15131635     7565786+   c  W95 FAT32 (LBA)   How should i fix this?


Ugly "Next Privilege" text on user activity page

It seems "See votes, expandable user card" goes on a second line on the activity page of the user profile resulting in a pretty bad look:    You can see it live on  (though of course that may change any day now depending on their rep-growth).  I'm using Chrome Version 67.0.3396.99 (Official Build) (64-bit)


How to draw lines across several subplots created using pgfplotslibrary groupplots


I have a CSV with 500 ship routes.  Every row is a different trip and the columns have the values of ship_name, lat_1, lng_1, lat_2, lng_2,lat_3, lng_3... lat_20, lng_20  How can I insert this information in QGIS and create polylines between this coordinates?


Bash_alias, run a script with a parameter and close console

I just created a script that runs a command using a parameter like so:  (firefox "localhost/?id=""$1" &)   I created the alias like so:  alias gotoid='/myscript.sh   As you can see, my script requires the parameter $1 to run. What I want is to be able to run my script using gotoid 3 for example and have the console automatically close without closing the Firefox window. When I change the alias to alias gotoid='/myscript.sh && exit", it starts firefox at the URL but doesn't take my parameter anymore, replacing the number going into id by (saw).  How can I make an alias for my script that allows the insertion of a parameter and close the console right after?  Thanks in advance.


Why does Ubuntu keep saying unattended-upgrades could not be installed?

Since a couple of days, when I log in Ubuntu 18.04, I receive the following message:  13 updates could not be installed automatically. For more details, see /var/log/unattended-upgrades/unattended-upgrades.log   I do not see anything particular in the log file.  The following lines are repeated every day (sometimes with an update):  2019-12-17 05:03:16,572 INFO Paquets faisant initialement partie de la liste noireÂ :  2019-12-17 05:03:16,580 INFO Paquets initialement sur la liste blanche:  2019-12-17 05:03:16,580 INFO DÃ©marrage du script de mise Ã  niveau automatique 2019-12-17 05:03:16,580 INFO Les origines autorisÃ©es sontÂ : o=Ubuntu,a=bionic, o=Ubuntu,a=bionic-security, o=UbuntuESM,a=bionic 2019-12-17 06:40:06,184 INFO Paquets faisant initialement partie de la liste noireÂ :  2019-12-17 06:40:06,201 INFO Paquets initialement sur la liste blanche:  2019-12-17 06:40:06,201 INFO DÃ©marrage du script de mise Ã  niveau automatique 2019-12-17 06:40:06,201 INFO Les origines autorisÃ©es sontÂ : o=Ubuntu,a=bionic, o=Ubuntu,a=bionic-security, o=UbuntuESM,a=bionic 2019-12-17 06:40:12,125 INFO Aucun paquet Ã  mettre Ã  niveau automatiquement ni Ã  supprimer automatiquement   If I manually force an update, the system says everything is up to date:  sudo apt upgrade Reading package lists... Done Building dependency tree        Reading state information... Done Calculating upgrade... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.   Is this above-mentioned message important? What can I do to eliminate it?


How to specify an asynchronous request in API JavaScript

I want to send to server (php) a request AJAX from an api javascript:   JS File :  var commit = new Object();  commit.id= this.id; commit.action = this.doCommit; commit.vrp= this.vrp; $.post(this.ajaxURL, commit);   with this code i can send a request but in mode asynchroun. I searched on internet and I found a solution :   $.ajax({     type: 'POST',     url: this.ajaxURL,     data: commit,     async:false });   I don't know if it is the best solution, or I can precise async:false in a  $.post request, if yes , how ?.


Can you derive ed25519 keys from secp256k1?

Alice has a secp256k1 key pair that she used some time ago when she communicated with Bob. Bob can no longer user secp256k1 but he only uses ed25519 instead.  Is there a secure algorithm that Bob can use to derive an ed25519 pubkey from original Alice's secp256k1 pub key and also Alice can derive the matching ed25519 private key from her original secp256k1 private key such that they can communicate securely via ed25519 encrypted messages?  Thanks!


Flag post to another website of the stackexchange network - why so few choices?

I followed the following steps to flag a post as "to move to another stackexchange website":  1) flag   2) it should be closed for another reason   3) off-topic because  4) This question belongs on another site in the Stack Exchange network  And here I was prompted just 5 websites.. the question I'm referring was this:  and it belonged to the  website (at least in my opinion).  Why so few options?


Find a function for the infinite sum $\sum_{n=0}^\infty \frac{n}{n+1}x^n$

I need to find a function $f(x)$ which is equal to the sum $$ \sum_{n=0}^\infty \frac{n}{n+1}x^n, $$ for every $x\in \mathbb{R}$ for which the series converge.  Now, using WolframAlpha, I've found the answer  $$f(x)=\frac{-x+x\ \text{log}(1-x)-\text{log}(1-x)}{(x-1)x},\ \ \ \text{when}\ |x|<1$$ However I'm trying to figure out how to find this function $f(x)$ on my own. I've tried to combine the Maclaurin series of $\ln(1+x)$, $\sin(x),$ and several other functions but I don't seem to succeed. Any suggestions how to work out this problem from scratch?


Prove by mathematical induction and determine when there is an equality

Let's assume that numbers  $x_1,x_2,...,x_n$ are of the same sign and that $x_1>-1, x_2>-1,...,x_n>-1$.Prove that $$(1+x_1)(1+x_2)...(1+x_n)\geq 1+x_1+x_2+...+x_n$$Determine when there is equality. So I have few questions regarding this problem. I tried two inductions first one$$(1+x_1+x_2+...+x_n)(1+x_{n+1})\geq1+x_1+x_2+...+x_n+x_{n+1}$$ Which evaluates to$$x_1+x_2+...+x_n\geq0$$And we can't conclude anything from that right? How is that that if we just 'change sides' and write this $$(1+x_1)(1+x_2)...(1+x_n)(1+x_{n+1})\geq(1+x_1)(1+x_2)...(1+x_n)+x_{n+1}$$we get$$(1+x_1)(1+x_2)...(1+x_n)\geq1$$and that gives us nothing too? And when the equality holds? Can the answer be formal?


What personal pronoun should be used with the noun "sheep"?

I would like to know what personal pronoun would be correct to use instead of  the word "sheep" in a sentence?     It is a sheep.   or       She is a sheep.   I'll try to explain myself in a better way. I know that when we speak about an animal, in general, we use the pronoun "It" : it is a dog for ex. but I read some were that "sheep" is an exception and has to be referred to as a "she" . But I can't find any confirmation to that.


Undo a comment upvote in the Android app

I just accidentally upvoted a comment while browsing SE using the Android app, and wanted to remove that upvote once I had realized my mistake.   However, there is no option to remove the upvote, while it seems  I still get the choice to upvote a comment although I already did that.  I chose upvote again, hoping this would effectively remove my upvote, but in fact it did nothing.


Understanding weight on an inclined plane

I'm trying to solve a problem where I have an object resting on an inclined plane, with the angle of the plan being alpha, and the weight being w. I'm having trouble figuring out how I can calculate the component of the weight parallel to the plane. I also want to find out the weight component perpendicular to the plane.  I don't want an outright answer, more of an explanation to help me understand. Thanks!


Badges in achievements dropdown should not have custom designs from sites they weren't earned on

I earned a badge on Ask Different. I found out about this via the achievements dropdown while I was hanging out on Science Fiction & Fantasy:     The badge in the dropdown is the icon that comes with the SciFi site design even though it is a badge on a different site. This is confusing, especially on a site like SciFi where the badge design is so distinctive. It makes me think I somehow earned a badge on SciFi for a question I asked on Ask Different.   If I view the dropdown on Ask Different, it looks better:    Badges in the achievements dropdown should either:   Use the icon that corresponds with the site on which the badge was earned (instead of the site you're currently on), or Use a generic icon in all cases (the  or  designs come to mind)


I cannot understand how capacitors work.   Electric field is supposedly uniform between the parallel plates of a capacitor.  But how?  Since $E=\frac{kq}{d^2}$, shouldn't the electric field approach infinity as one approaches either of the two plates ($d=0$), while it would be smaller in the middle? There is air between the capacitors, right?  Air isn't a conductor, is it?  Circuits in which the wires are interrupted by air aren't closed, are they?  Yet circuits still function with capacitors in them and charge is brought from one plate to the other while there is air between the plates.  What is going on there?   Thank you


How can I use the grep --color command to highlight brackets?


How can I show that $\{(x,y,z) \in \mathbb{R}^3 : x^2 + y^2 + z^2 = 1 \}$ is connected?

I am having a lot of trouble showing that this set is connected. $$\{(x,y,z) \in \mathbb{R}^3 : x^2 + y^2 + z^2 = 1 \}$$  This set contains all of the points on the boundary of a sphere (or the surface, if you like) with a empty core/inside.   What I have tried doing is proving path connectedness, by picking two arbitrary points a and b and defining a map $ [0, 1] $ that maps on S, but I am not sure how to construct such a path since I need to go around the circle. Though a technique I have also tried is going through the sphere and simply projecting every vector on the line onto the sphere (by dividing every point on the line with its norm resulting in a unit vector) - however I am not looking for "tricks" and a rather more robust solution - something that I can learn from. :)  Any help appreciated!


'Sorry' as a replacement for 'Excuse me'?

Is it ok to say 'sorry' where you otherwise would use 'excuse me'?  Example: "Sorry, but could you show me the way to the next train station?"


Has JKR confirmed what theory is correct about Harry surviving in the Forbidden Forest?

When Harry is hit by Voldemort's killing curse in the Deathly Hallows, why was he able to choose to come back? I've heard essentially 3 arguments, any of which might explain it.   The curse only killed the part of Voldemort's soul attached to Harry, who just took a ride with it to Limbo. Lily's enchantment of protection sustained Harry, maybe in part because it still existed in Voldemort's body. Harry owned all three Deathly Hallows, and therefore had command over death.   Has JKR confirmed any of these or other theories about Harry's non-death? Interview quotes are great, and obviously quotes from the books are good too.


How to set gnome-session-flashback as default in 16.04?

I customized my system by installing Ubuntu 16.04 and replacing Unity with gnome-session-flashback.  How can I switch Unity desktop to GNOME desktop without selecting the session at the login screen?


Relationship terminology after death of a relative

Please can someone tell me, when a married woman dies, would her widower still be called the son in law of his late wife's parents?  If so, would that title continue to apply if he remarried? He might then have a new mother and father in law, so could he be son in law to both sets of parents?


How to enable the 2 concurrent (+1 console) sessions on Windows Server 2012

I have a Windows Server 2012 VM running on Windows Azure.  I want to enable the ability for 2 simultaneous administrative sessions over Remote Desktop. This is permitted under the EULA for Windows Server 2012. This is not the same thing as the fully-blown Terminal Services (Remote Desktop Services) feature.  In Windows Server 2000 and 2003, multiple concurrent sessions (up to a limit of 2, plus the root /console session) were enabled by default (such that logging-in via RDP without logging-out first would create a new session rather than reconnecting to the old session). In Server 2008 and later it uses single-sessions by default, as this simplifies administration (as most people want to connect to old sessions).  In Windows Server 2008 R2, you can add the MMC snap-ins for Remote Desktop Host Configuration which allows you to re-enable concurrent sessions.  However, in Server 2012, after adding the Remote Administration snap-ins from Server Manager it seems the Remote Desktop Host Configuration snap-in has been removed.  How can I re-enable the multiple concurrent sessions for Remote Desktop for Administration in Windows Server 2012?


Is there a list of Open Source tool alternatives for ArcGIS tools?

Is there any place one can find a list of ArcGIS alternative or near-alternative tools found in (any of) the open source softwares? I am not looking for software but individual tools found in the software.  I started my GIS career with ArcGIS. Today I am using more and more Open Source software such as QGIS, SAGA GIS, and R among others. I have spent hours and hours of time when finding different tools that do the same thing as those so conveniently found in ArcGIS (because you know what to look for). It would be very convenient and time saving to just check the alternative from a list than spend time googling and reading various manuals and doing trial and error at your desktop.  e.g., ArcMap: Spatial Analyst: Raster calculator - SAGA GIS: Grid Calculus: Grid Calculator   I see that there are several threads dealing with this, but they are regarding this with a smaller scope:        I am looking after a comprehensive, "dictionary type" of list.   So is there a comprehensive list or a site regarding this, and if not, how could we get one? I think this would be very useful for a whole lot of people!


What is the reason behind the equation $p = mv$?

Now this is a very basic question, might look stupid too, but I am not able to understand it. I tried to imagine what momentum really is, and it is the impact of an object. I understood how  works, but cannot understand its mathematical formulation. We all know that $p = mv$, but how does this equation work? I mean just by multiplying mass and velocity, how are we able to get this impact? Is there any derivation to this equation?


What are the characteristics of a memristor?

This is an in-spirit follow-up to my earlier    So I'm an electronics hobbyist, and I've been curious for a while about the proposed new component, the memristor. My research has turned up  link demonstrating the creation of one, and now I'm wondering, how do you define and measure a memristor? If a memristor relates charge and flux, how does an oxidized metal perform like this? finally, do all (or most) metal oxides have these characteristics?  I realize that this is probably a lot, but what I've seen out on the internet regarding this has left me very confused.  Thank you for your help.


Dual boot windows 8.1 and ubuntu 13.10, unusable drive space

I have Windows 8.1(64-bit), i want to dual boot it with ubuntu 13.10(64bit),  I shrunk the C: drive by 20 GB. created a bootable pendrive and booted through it    when i clicked on "something else", the 20GB data i have partitioned is showing "unusable"    i tried using gparted its showing "it is not possible to create more than 4 primary partitions"  please help, i am new to ubuntu  my system specs: core i3(3rd gen), 4GB RAM, 500GB HDD, Dell inspiron 14r  I do not have enough reputation to upload images so i have given the links.


What differences are there between 2.5" and 3.5" disks?

Besides price and size, what difference are there between a 1TB SATA 3.5" and 2.5" HDD?  Are there pro/cons in regards to noise/through put/response time/robustness?


Show us who submitted offensive and comment flags

There are three types of flags moderators get to deal with--standard flags (low quality, other), spam/offensive flags, and comment flags.  Within the moderator dashboard, we can see who has submitted a standard flag.  However, we do not see who has submitted an offensive/spam flag nor a comment flag.  Is there a reason for this?  If not, I'd like to be able to see the name of the user who has submitted a flag, no matter what type.    For those scoffers who scoffed at me:    Now, how should I handle this situation?  I could guess at who did this, but it would only be a guess.  Scoffers suck.


Spotify, Youtube, Shockwave Flash, and other programs not working

When I open spotify it will continuously load or if it stops i cannot play a song, also on Youtube i can click on a video from the homepage but the video will not load and i cannot click on anything. Other video sites will also crash and i get the "shockwave has stopped working" popup. Even Windows Media Player, skype, and steam don't work. I have updated countless things, restarted multiple times, and checked for viruses and have gotten no change. Is there anything I should do or do i need to just reboot to an earlier date? Sometimes Youtube will work for one video then no longer work at all.  I have done a spybot search and an avast search and neither came up with anything. I also don't believe i have any refresh dates for my computer so I want to use that as a last choice.


Objects look different in rendered preview shading compared to material preview

Objects look amazing in the material preview mode, but not in the render preview (and also when rendered). I have attached two screen shots of a metal sphere in both viewports. Can anyone tell me what is wrong?


How /or what QGIS plugin do I use to open these layers? (they seem to be served by Geoserver)

I'm new to this field. I'm trying to open in QGIS the layers that are provided in this page: .  (each layer has a links option)  I have some links but I dont have any info on what standard are those, or how do I open them. (They seem to be served by Geoserver). I tried with OpenGeo Explorer plugin but those Links dont work. I also tried to add them as WMS/WMTS Layer in QGIS but nothing. (the legend of the layer appears some times, but the vector layer itself doesnt show up)  I have seen two types of links in that page so far.   and    Anyone knows what tool should I use to access & analyse those layers?


Is $\mathbb{Z}[t,t^{-1}]$ a PID? What about $\mathbb{Z}[\sqrt{2}i]$?  I don't know how to prove that a set IS a PID. I only know how to prove when it is NOT (by proving it is not UFD, for example).  How can I show an ideal can only be generated by a single element? In $\mathbb{Z}$ I understand, there is a minimality argument. But in those sets up there I have no idea how to start.


why is javascript treating variable as string?

In the following code why is i treated as a string? I have to multiple it by 1 to get it to convert back to a number.    getPositionInArray(value, array) {     console.log('array = ', array);      let i = 0; // why is i a string?     for (i in array) {       if (array[i].toLowerCase() === value) {         let positionOnUI = i * 1 + 1; // why can't I use i + 1?         return positionOnUI;       }     }     return null;   }


Could dark matter be made of black holes?

I have read these questions and their answers:         None of those answered what I am asking.  Dark matter:   does not interact with EM waves, so it is not visible directly creates gravitational effects   Black Hole:   does not let EM waves escape, so it is not directly observable creates gravitational effects   Based on these facts, there seems to be a similarity between dark matter and black holes.   Could it be, that the regions of space (intra-galaxy clusters) where we found gravitational effects that cannot be explained with normal matter, so where we suspect dark matter to exist, that that region of space in between galaxy clusters is just a region that is full of black holes that would have the same gravitational effects and would not be visible directly?


Why was Anakin's mother not protected/taken care of?

When Anakin is introduced to the council to be made a padawan, the council finds fear in him.  Part of their reluctance to take him as a padawan is the fear he seems to possess.  Considering the limited number of jedi and the resources they have, I don't think that placing his mother on a safe planet, not enslaved, would have been very difficult.   In general, they take the children very young so they don't get attached to their family. So it's not like they have many families to take care of. And I'm not saying to pay her mother a monthly income, just to move her to a safe place, and free her. She can survive on her own afterwards.  As they took him older, as an exception, it just makes sense to make another exception and help his mother.  Seeing his mother being tortured in his dreams then seeing her die was the first step on the dark side, which could have been avoided very easily.  So considering that he is the "chosen one" and that he seems pretty unstable, why didn't they take care of his mother?


Prove that MCD is 1 or 3 knowing (a,b) = 1

I'm don't know from where to start in this problem. I have to prove that     $(a+b,a^2-ab+b^2)=1 \text{ or } 3$   knowing that $(a,b) = 1$.  I've tried using the method they taught us on class, so I've written that:     $d\ |\ a+b \Rightarrow d\ | a^2 + 2ab + b^2$  and $d\ |\ a^2-ab+b^2 $   $\Rightarrow d\ | \ 3ab$   But from here, I dont know where to go. Usually, I should be able to  find that d divides something in terms of a, and something in terms of b, and therefore, using that $(a:b)=1$ I would get the solution. But this is not the case. Any operation I've tried between the two terms, gives me an other term, but always in terms of a and b, and no a or b, so I'm not able to prove what I'm asked.  Any ideas?


What is the Mac equivilent of ALT+PrintScreen?

I've just started using Delphi to create OSX programs. I'd like to be able to take a screenshot of just the currently active window on the Mac and save it to the clipboard. On Windows you press [Alt] + [PrtScn].   What is the equivilent on a Mac?


How can I prove my publication list is mine?

In some of the questions regarding author name, it is mentioned that people can use whatever they like, however, they must be consistent across their publications.  When it comes to being hired by a university for a tenure track position or by another principal investigator as a researcher, how can someone prove that they are the author of papers when their author name does not exactly match the one on their ID card? How can a principal investigator be sure that the publication list does actually belong to the person claiming them?


How to access "The grimm Troupe" and "Hidden dreams" content in Hollow Knight?

In these two official announcements from Team Cherry, it's said:       Grimm’s quest, and all other new features can be accessed at any point   in your Hollow Knight journey.        Hollow Knight: Hidden Dreams content is accessible at any point in the   game, whether starting fresh or scouring for completion.   I still haven't find any way to start the quests from the menus or during beginning of the game. Some sources say the content can only be accessed late in the game from specific locations.  So, is Team Cherry simply lying in our faces?


How do I replace accented Latin characters in Ruby?

I have an ActiveRecord model, Foo, which has a name field.  I'd like users to be able to search by name, but I'd like the search to ignore case and any accents.  Thus, I'm also storing a canonical_name field against which to search:  class Foo   validates_presence_of :name    before_validate :set_canonical_name    private    def set_canonical_name     self.canonical_name ||= canonicalize(self.name) if self.name   end    def canonicalize(x)     x.downcase.  # something here   end end   I need to fill in the "something here" to replace the accented characters.  Is there anything better than  x.downcase.gsub(/[àáâãäå]/,'a').gsub(/æ/,'ae').gsub(/ç/, 'c').gsub(/[èéêë]/,'e')....   And, for that matter, since I'm not on Ruby 1.9, I can't put those Unicode literals in my code.  The actual regular expressions will look much uglier.


took the 12.15 train OR caught the 12.15 train

Please help me to understand these complicated verbs 'to take' an 'to catch'.  I know the difference from the related topics, google e.g. "If you want to go over to Sixth Ave., you'd better take the crosstown bus. You can catch it at Broadway...."  BUT I can't see the difference between  'they caught the 12.15 train from Oxford'  'they took the 12.15 train from Oxford'  which one is more idiomatic in terms of BrE or AmE?  p.s. please do not write that it is duplicate because it's impossible to find answer to my question. They are very useful, I've read them for many times, but I can't see clearly the difference in my examples above.


Error " but was:". Tell me please, what's wrong with the code?

Write a method that will withdraw money from a particular customer's account and return the balance on the account. If there is not enough money on the account, the method will return -1  The signature of the method - withdraw (String [] clients, int [] balances, String client, int amount)       package Lesson5;  /**  * Created by Ruslan on 12.06.2017.  */ public class takeOffBalance {     public static void main(String[] args) {         String clients[] = {"John", "Pedro", "Valera", "Muchachos", "Vovan"};         int [] balances = {1, 100, 3500, 222, 1234};         System.out.println(withdraw(clients, balances, "Pedro", (int) 10000));     }      static int withdraw(String[] clients, int[] balances, String client, int amount) {          int res = balances[findClient(clients, client)] - amount;         return res >= 0 ? res : -1;      }     static int findClient (String [] clients, String client) {          int clientIndex = 0;         for (String name : clients) {             if (name == client) {                 break;             }             clientIndex++;         }         return clientIndex;     }   }


Can TOR prevent my ISP from seeing what I download?

Having issues with my ISP monitoring my activity and blocking my internet access when they see something they don't like. Can I utilize TOR to prevent this monitoring with out tipping off my ISP to my security?


How to open hibernated windows NTFS partition?

I have a dual-boot PC with Windows 10 and Ubuntu 16.04. I keep my Windows on fastboot mode and hence the NTFS partitions used in Windows, not open in Ubuntu. I want them to open in Ubuntu while keeping Windows in hibernation (fastboot mode).  I already searched and googled but I can't get an acceptable solution. How can I do so?


Where to include javascript instances in drupal

I've added my.js using js injector module and updated .info file. Where do I have to create those instances? Sorry, I'm new with technology.


Were the people of the galaxy not concerned that Palpatine had named a Sith as his number 2 in the Empire?

Were the people of the galaxy not concerned that Palplatine had named a Sith Lord as his number 2 in the Empire?


Stuck on proof of a martingale equality (similar to doob's inequality)

The question is: Let $M$ be a positive, continuous martingale that converges a.s. to zero as $t$ tends to inﬁnity. Prove that for every $x > 0$ $$P\{\sup_{t\geq 0} M_t > x \,| \,F_0\} = 1\wedge \frac{M_0}{x}$$ almost surely.  From Doob's martingale inequality we may conclude that $P\{\sup_{t\geq 0} M_t > x \,| \,F_0\} \leq 1\wedge \frac{M_0}{x}$, but right now I'm stuck on showing that $$P\{\sup_{t\geq 0} M_t > x \,| \,F_0\} \geq 1\wedge \frac{M_0}{x}.$$ On this part I'm completely clueless right now. Any tips?  P.S. We were given the tip "stop the martingale when it gets above $x$", but I don't see what we can do with such a stopped martingale.


Is there a way to get the extent (bbox) of a vector layer in QGIS?   I see that I can update the extent, but I am looking for the actually coordinates of the extent.


Can I play Pokemon Go in a country that I am visiting?

I'm from the United States and I'll be visiting Canada soon. Since Pokémon GO is not out for Canada yet, would I still be able to play and catch Pokémon in Canada seeing as my phone/game/account all originate from the United States?  For that matter, will I be able to play Pokémon GO in Canada once it is released in Canada? Or am I restricted to playing in the United States only?


How do I create my own URL protocol? (e.g. so://...)

I have seen:   http://www... ftp://blah.blah... file://blah.blah... unreal://blah.blah... mailto://blah.blah...   What is that first section where you see http and the like called?  Can I register my own?


When defining a wrapfigure (or a minipage), I need to specify the width of the figure. Is there a possibility that this width is determined by the picture inside? For sake of an MWE, I'll use a tikzpicture. I don't want to chage the scale of the image since my image is used multiple times in the document, but in different variations and it should have the same scale all the time. \documentclass{article} \usepackage{wrapfig} \usepackage{lipsum} \usepackage{tikz} \usepackage[justification=centering]{caption} \begin{document} \begin{wrapfigure}{r}{5cm}     \centering     \begin{tikzpicture}         \draw (0,0)circle (2);     \end{tikzpicture}     \captionof{figure}{A circle} \end{wrapfigure} \lipsum[1] \end{document}  This looks bad:  Adding \centering improves a bit, but then I still have too much spacing left and right. I want to have an output like this:  (This was created using 4cm as width, but I don't want to guess the size of the image - easy for the circle, harder if you have a more complicated image) To  sum it up, is there an option to fit the width of a wrapfigure (or any environment, like a minipage) to an image without rescaling the image and without guessing the size? Edit: Not a duplicate of , since in this case the author knows the width of the image and therefore can specify it, I don't.


Drawing Lattice/Trellis Graphs using PGF/TikZ

I am trying to draw a graph containing lattice points and vectors.  I wish it to look something like this:    I am not sure how to go about it, however, I would ideally like to be able to use PGF/TikZ.  Is this possible, or would I need to download and install a package like GeoGebra to create the graph, and export it into PGF/TikZ format?  Again, I am not sure whether or not this is possible using GeoGebra.  Any suggestions would be appreciated.    Follow-up Question: