Suppose we can only use $5$ kinds of tiles to cover a $1 \times n$ board: (1) $1 \times 1$ size with red color, (2) $1 \times 1$ size with blue color, (3) $1 \times 2$ size with black color, (4) $1 \times 2$ size with green color, (5) $1 \times 2$ size with white color. Let $W(n)$ be the number of ways to tile the $1 \times n$ board, $n = 1, 2, \ldots$. For example, $W(1) = 2$, $W(2) = 7$, as shown by the following figure.  What is the $W(n)$ equation?


Can we copy a string with a command-line and have the ability of pasting it with Ctrl + V shortcut?


Cannot use Alt code for Unicode character insertion any more

I've been using the  for the ellipsis, 8230, for some time now, in several applications. A few days ago it stopped working, and & is displayed instead of … when pressing Alt+8+2+3+0 (on numpad). This happened both on my desktop and on my laptop (where I use it with Fn). Both run on 64bit-Win-7 with code page 850, and both might have recently updated Windows and Opera 12.  What could be the reason this input method got disabled, and how do I switch it back?  By the way, I just found out that Alt+0+1+3+3 does work. Also I found out that Alt+8+2+3+0 still works in WordPad or MsWord10, but neither in Opera nor Notepad++ - there the character code is translated modulus 256 before insertion.


Switching from Windows 7 to Kubuntu - NTFS disk conversion

I'm going to be making a switch from Windows to Linux, but all my HDD's are NTFS-formatted. I understand I would have to format the boot disk and lose all data, but what about the other HDD's that don't contain OS's and are used for data storage purposes only - can I somehow convert them to a Linux-supported filesystem without losing data?


How can I integrate the exponential $\int_{-\infty}^{\infty} e^{-au^2} du$?

How can I integrate:  $$\int_{-\infty}^{\infty} e^{-au^2} du$$  Please note that I want to learn a step by step approach for doing so.


service user unable to create/modify files in directory they own

I must be missing something. I created a service account that will run a script I created as a cron job. The script links files to be processed to a watched folder. The script worked fine running as root, but I thought it was best to use a service account and have the cron job run hourly under that account. Now I'm running into permissions issues when I try to create files/folders as the service account.    [root@analysis ~]# ls -l /watched/robert.sicko/  total 24   drwxrwx--- 20 srvArcherNBS srvArcherNBS 20480 May  8 11:35 XXX   drwxrwx---  2 srvArcherNBS srvArcherNBS  4096 May  4 11:04 test  [root@analysis ~]# su -c "touch /watched/robert.sicko/test/abc.completed" srvArcherNBS  touch: cannot touch `/watched/robert.sicko/test/abc.completed': Permission denied   Other info. The server runs CentOS release 6.10.  watched, robert.sicko and test directories already existed, I changed ownership of /watched/robert.sicko/* to the service account with:   chown -R srvArcherNBS:srvArcherNBS /watched/robert.sicko/*   the /watched dir isn't owned by srvArcherNBS, but changing the group of /watched and /watched/robert.sicko to srvArcherNBS didn't change anything  [root@analysis watched]# ls -l total 4 drwxrwx--- 4 apache archer_daemon_web_access 4096 May  4 11:04 robert.sicko   edit to add result of ls /watched/robert.sicko/test/abc.completed:  [root@analysis /]# ls -l /watched/robert.sicko/test/abc.completed ls: cannot access /watched/robert.sicko/test/acb.completed: No such file or directory   edit2 to add to the weirdness - running ls with su as srvArcherNBS gets permission denied but if I su srvArcherNBS, I can then ls.  [root@analysis robert.sicko]# pwd /var/www/analysis/watched/robert.sicko [root@analysis robert.sicko]# su -c "ls -la /var/www/analysis/watched/robert.sicko" srvArcherNBS ls: cannot access /var/www/analysis/watched/robert.sicko: Permission denied [root@analysis robert.sicko]# su srvArcherNBS [srvArcherNBS@analysis robert.sicko]$ ls -la total 32 drwxrwx---  4 apache       srvArcherNBS  4096 May  4 11:04 . drwxrwx---  3 apache       srvArcherNBS  4096 Mar 27  2019 .. drwxrwx--- 22 srvArcherNBS srvArcherNBS 20480 May  8 15:10 XXX drwxrwx---  2 srvArcherNBS srvArcherNBS  4096 May  4 11:04 test [srvArcherNBS@analysis robert.sicko]$   output of mount  [root@analysis robert.sicko]# mount /dev/mapper/VolGroup-lv_root on / type ext4 (rw) proc on /proc type proc (rw) sysfs on /sys type sysfs (rw) devpts on /dev/pts type devpts (rw,gid=5,mode=620) tmpfs on /dev/shm type tmpfs (rw) /dev/sda1 on /boot type ext4 (rw) /dev/mapper/VolGroup-lv_home on /home type ext4 (rw) none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw) //prd/agtcnbs on /mnt/agtcnbs type cifs (rw             )


How to wait a file for 90 seconds ,if it didnot create within 90 seconds we should make timeout and exit the function.If it creates within this time of 90 seconds it should return as true  I did following code with failure  private bool Wait(string filePath, int maxSecs, ref string errDesc)     {         System.DateTime timeNow = System.DateTime.Now;         bool timeOut = false;         try         {             System.Threading.Thread.Sleep(2000);              if (System.IO.File.Exists(filePath))                 return true;             System.DateTime currentdatetime = System.DateTime.Now;             TimeSpan diff = currentdatetime - timeNow;             //timeOut = Math.Abs(DateDiff(DateInterval.Second, timeNow, System.DateTime.Now)) >= maxSecs;              if (timeOut)             {                 errDesc = "File creation failed";                 return false;             }             System.Threading.Thread.Sleep(2000);         }         catch (Exception ex)         {             errDesc = ex.Message;         }         return timeOut;     }


Why is this chunk of code giving me a NullPointerException?

I am attempting to run a Sudoku game code in java (Using NetBeans) and am currently writing the method that initializes the game and reads the file containing the starting game code. The text file reads as so:  0,0,2,9,8,0,5,0,0 4,0,0,0,7,0,0,1,3 0,3,9,6,0,4,0,7,0 2,0,0,0,5,6,4,0,0 8,4,0,3,0,0,2,0,1 9,0,7,0,0,1,0,8,6 6,0,0,7,0,5,1,3,0 0,9,1,4,0,0,0,0,5 0,2,0,0,3,0,6,0,8   My current code being run is:          Scanner f = new Scanner(new FileReader("C:(MY FILE LOCATION)"));         for (int i = 0; i < 9; i++) {             line = f.next();             readLine = line.split(",");             for (int j = 0; j < 9; j++) {                 gameBoard[i][j] = readLine[j];             }         }   The NullPointerException comes from the line of code:  gameBoard[i][j] = readLine[j];   When I don't declare the numbers to the game board and just print them out instead it works just fine. I already having it throwing FileNotFoundException. Thanks for any help!


I'd like my program to find location from which it was run, i.e. program uses txt file and I'd like it to look for this txt file in the same directory as jar file.  I am aware of the existence of Path class, but I don't have a clue how to use it in this situation. For the time being I'm using a fixed path, but it's not good enough.  package readsqlfromfile; import java.io.*; import java.util.Scanner;   public class ReadSqlFromFile {  static File file = new File ("C:\\sql\\sql.txt");  public static void main(String[] args) throws FileNotFoundException  {       Scanner input =new Scanner(file);      String linia = new String ("");  while (input.hasNextLine()) {     linia = input.nextLine();     if (linia.length()>4) {     if (linia.substring(0, 4).equals("sql:")) {        //some database logic here    }    }        }  } }


maximum value of the expression : $2x+3y+z$ as $(x,y,z)$ varies over the sphere $x^2+y^2+z^2=1$

I have to find out the maximum value of the expression :          $2x+3y+z$ as $(x,y,z)$ varies over the sphere $x^2+y^2+z^2=1.$


Calculation result is different depending on decimal or double

Can someone please explain why the calculated value 180 * 2.2 will be different when stored in a decimal vs. a double; and perhaps also explain why .NET is calculating 180 * 2.2 with a decimal point in the first place?   Standard Calculator: 396 Expression (Double): 396.00000000000006 Expression converted to decimal: 396


I cannot understand why my flag was marked as helpful if no action was taken on it.  I am talking about this flag on .        It's helpful but no action was done on it.  Any explanation how flag was helpful?


Meaning of inner product $\langle \vec{r} | \psi(t)\rangle $

I have come across the equation which comes out of the nothing  in Zettili's book Quantum mechanics concepts and applications p. 167:  $$\psi(\vec{r},t) ~=~ \langle \vec{r} \,|\, \psi(t) \rangle.$$   How do I know that I get function of position and time if i take an inner product of a state vector with an vector $\vec{r}$? Where is the proof?


Android Spinner set adapter method showing null pointer exception

I am trying to create one form.but at the time of adding spinner it is showing null pointer exception.What should i do?How Can i Solve this? Everytime i use spinner it gets me error at setAdapter() method this is my code...  import android.app.Activity; import android.os.Bundle; import android.support.design.widget.FloatingActionButton; import android.support.design.widget.Snackbar; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.view.View; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.Spinner;  import java.util.ArrayList; import java.util.List;  public class Complaint extends AppCompatActivity implements       AdapterView.OnItemSelectedListener {  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.content_complaint);      Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);     setSupportActionBar(toolbar);     Spinner sp=(Spinner) findViewById(R.id.spinner);     List<String> categories = new ArrayList<String>();     categories.add("चौकशी");     categories.add("तक्रार");     ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>   (getApplicationContext(), android.R.layout.simple_spinner_item,categories );      // Drop down layout style - list view with radio button     dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);      // attaching data adapter to spinner     sp.setAdapter(dataAdapter);      sp.setOnItemSelectedListener(this);  } @Override public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {  }  @Override public void onNothingSelected(AdapterView<?> parent) {  }}


Half of my custom skin doesn't change when I edit it and save and upload it and it's frustrating because I'm just trying to make that half black... Can anyone help me out?        [  I'm using 1.7.10, but it let me change my skin before but not now, so it's just weird.


Show that the curve $2Y^2 = X^4 - 17$ has no points in $\mathbb{Q}$

There is a hint to show that if there were points in $\mathbb{Q}$, then there would exist $r,s, t \in \mathbb{Z}$ with $\gcd(r, t) = 1$ such that $2s^2 = t^4 - 17r^4$ , and then show that any prime dividing $s$ is a quadratic residue modulo $17$.  I'm stuck on the first bit - if you suppose $\left(\frac{a}{b}, \frac{c}{d}\right)$ is a point on the curve in $\mathbb{Q}$ (so $a, b, c, d \in \mathbb{Z}$) then you get to $2a^2d^4 = b^2c^4 - 17b^2d^4$, but I'm not sure where to go from here since you don't know that $b$ is a square?


Regular Expression to match nested curly braces

I have String in below form :     {1:F01ANZBSGSXAXXX166753}{2:O1030921091130DEUTSGSGXXXX28705821270911234}{3:{103:MEP}{113:NORQ}{108:10ROTRM911250002}}   I have to create a regular expression in order to get following substring from the above string :   {1:F01ANZBSGSXAXXX166753} {2:O1030921091130DEUTSGSGXXXX28705821270911234} {3:{103:MEP}{113:NORQ}{108:10ROTRM911250002}} {103:MEP} {113:NORQ} {108:10ROTRM911250002}      The pattern it follows is : Pattern = {key:value}  where value can   contain nested Pattern   I tried to form one : ({\d*:[\s\S][^}]*}) But this one fails in case of substring 3 i.e. in case of nested expression.


trouble understanding some parts of integration,

what does $dx$ mean in: $$\int f(x)dx$$ and is it true that, if $\frac{df(x)}{dx} = g(x)$, then: $$\int g(x)dx = \int df(x)$$


Let $G'$ be the commutator subgroup of $G$. Prove that if $H$ is a subgroup of $G$ and $G'\subset H$, then $H$ is normal in $G$.  I do not know how to prove it. I have tried different ways but all of them were unsuccessful. However, I know that $G'$ is normal in $G$ and quotient group $G/G'$ is abelian.  Can anyone demonstrate how to solve that problem.


Let $(I_n)_{n\ge2}$, $I_n=\int_0^{\pi/4}{\tan^n x \, dx}$  Find $\lim_{n\to\infty}\int_0^{\pi/4}{\tan^n x \, dx}$. $I_n$ is a sequence of (definite) integrals. I don't know any other way to calculate a limit of such sequence than using the Squeeze Theorem.    I can't find two bounds for $I_n$ whose limits as $n\to\infty$ are equal. First thing I tried was considering the double inequality $0 \le x \le \pi/4$ and rewriting it I got $0 \le I_n \le \pi/4$. I realize this is only true for $n \ge 0$ which is not the case in this exercise because $n \ge 2$. $I_2 = 1 - \pi/4$ so this is the upper bound of the $I_n$, then the double inequality becomes:  $$0 \le I_n \le 1 - \frac{\pi}{4}$$ I can't apply Squeeze Theorem because limit of left term is not equal to the right term and this is often the case with a lot of exercises of this kind that I attempt. I realize that I need to find two functions (of $n$) that can substitute the bounds for $I_n$, but I just have no clue what those would be, please give me a hint.


Why I can't change my username in Terminal?

I started working recently with Ubuntu and changed my username. I changed the "v" tiny by capital "V", but in Terminal remains the same.


The union of two linearly independent subsets

This is a question from Finite-Dimensional Linear Algebra by Mark S. Gockenbach page 57 (exercise 2.5.15). I hope to check my proof.  Let $V$ be a vector space over a field $F$, and suppose $S$ and $T$ are subspaces of $V$ satisfying $S \cap T = \{0\}$. Suppose $\{s_1,s_2, ..., s_k\} \subset S$ and $\{t_1,t_2, ..., t_l\} \subset T$ are both linearly independent sets. Prove that $\{s_1,s_2, ..., s_k,t_1,t_2, ..., t_l \}$ is a linearly independent subset of $V$.  My proof) Suppose that $\alpha_1 s_1 +...+ \alpha_k s_k + \alpha_{k+1}t_1 +...+ \alpha_{k+l}t_l = 0$ for some $\{ \alpha_i\}_{i=1}^{k+l} \subset F$ Then $\alpha_{k+1}t_1 + ... + \alpha_{k+l} t_l = -(\alpha_1 s_1 + ... + \alpha_k s_k) \in S$ Since $\{ t_1,...t_l \} \subset T$ and $T$ is a subspace of $V$, $\alpha_{k+1}t_1 + ... + \alpha_{k+l} t_1 \in T $. Since $S \cap T = \{0 \}$, $\alpha_{k+1}t_1 + ... + \alpha_{k+l} t_l = 0$. Since $\{t_1, ... , t_l \}$ is a linearly independent set, $\alpha_{k+1} = ... = \alpha_{k+l} = 0$. By doing similarly, we can show that $\alpha_1 = ... = \alpha_k = 0$. Therefore, $\{s_1,s_2, ..., s_k,t_1,t_2, ..., t_l \}$ is a linearly independent subset of $V$. $\blacksquare$


Changing the Windows 7 same folder file copy naming pattern?

On my Windows 7 machine, when I make a copy (Ctrl+C, Ctrl+V) of a file in the same folder I get the new file created with " - Copy" added to the file name:  1st copy: "foo.txt" -> "foo - Copy.txt". 2nd copy and so on: "foo.txt" -> "foo - Copy (2).txt".  Is there a way to change this naming pattern?  Particularly I'm interested in changing the naming from " - Copy (index)" to "_index", so that the files would be named foo_1.txt, foo_2.txt and so on.  I know there are 3rd party file managers that can do this, but I would like to know if there is a way to change this naming pattern in explorer.


The correct usage of tags Chat Support mobile-web 'bug-feature request discussion support'

I am new here. I was wanting to know if you can use tags whenever I am answering another person's questions? Tags have me a bit confused?   Chat Support mobile-web 'bug-feature request discussion support'.


Regex for finding the text inside parentheses followed by @en : "example"@en

I was using "(.*?)"@en but it does not detect an input with three dots : "..."@en  This is the guilty line:  <http://dbpedia.org/resource/%C2%85> <http://www.w3.org/2000/01/rdf-schema#label> "…"@en .  Is there a way to make it detect all characters?  I am using Java's Pattern and Matcher.


USB charger - tell the phone it can draw more power

I have 8A 6port usb charger. It has two ports marked as fast charing, and the phone here actually charges faster than in the two other ports. When I dismantled it, all the USBs were on the same power line, so the charger is definitely somehow telling the phone how much current can it use.  There are bunch of resistors around the ports, looks like connected to the data pins, but I will have to desolder the USB's to see how they are connected, as most of the paths are on the PCB covered by the ports. I would like to be able to make the third port also fast charge (don't worry, I know there are current limitations and the other ports are used for handsfree and smartwatch cahrging which takes ~500mA, and as the phones draws ~2A, it will still be in the power source's limits). I tried to find a schematics for the resistors connections, but only thing I was able to find is about how it's done for Apple and tons of articles about quickcharge with no tech specs.  Only thing I need is to tell Android phone it could draw more than 1A from the USB. I'm also going to build charging station from PSU (5V 30A) and here I would also want to tell the phones that they could draw more power. Thanks for any help.


When I try to install tor I get:  Reading package lists... Done Building dependency tree Reading state information... Done Package tor is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package tor has no installation candidate   I was able to install it a few days ago, then I had to remove it sudo apt-get remove --purge tor  And now I cannot install it.  Any idea why?


Applications for the class equation from group theory

I have seen and studied this class equation for a finite group acting on itself by conjugations. The only applications I know are Cauchys' theorm and Sylow's theorem. Are there more?


Common style for global TOC, LOF, LOT and titletoc partial TOCs (with hyperref & caption)

I am currently writing my PhD thesis, and I have trouble defining a common style for my global TOC and the partial TOCs generated by titletoc.  Basically if you check the following MWE, I like the general style of the global TOC, in particular the fact that hyperref links include the labels. However, I find that the dotted lines in the global TOC are not dense enough, and prefer those of the partial TOCs.  \documentclass[12pt,a4paper]{book}  \usepackage{caption} \usepackage{titletoc} \usepackage[colorlinks]{hyperref} \usepackage{lipsum}  \renewcommand{\cleardoublepage}{\clearpage}  \newcommand{\PartialToc}{\vspace*{0.5pc}\vbox{\bf\large\noindent Chapter contents}\vspace*{0.3pc}\startcontents[chapters]\vspace*{0.3pc}\printcontents[chapters]{p}{1}{}\vspace*{0.3pc}}  \begin{document}  % Custom style for partial TOCs \titlecontents{psection}[3.6em]{\small\bfseries}{\contentslabel{1.8em}}{}{\mdseries\titlerule*[0.25pc]{.}\contentspage\hspace*{1.8em}}{} \titlecontents{psubsection}[6.0em]{\small}{\contentslabel{2.4em}}{}{\titlerule*[0.25pc]{.}\contentspage\hspace*{1.8em}}{}  \tableofcontents \listoffigures \listoftables  \chapter{Chapter 1}  \vfill \lipsum[1-2] \vfill\PartialToc\clearpage  \section{Section 1} \lipsum[1]  \begin{figure}[t]     \caption{Figure 1} \end{figure}  \section{Section 2} \lipsum[1] \subsection{Subsection 2.1} \lipsum[1] \subsection{Subsection 2.1} \lipsum[1] \section{Section 3} \lipsum[1]  \begin{table}[t]     \caption{Table 1} \end{table}  \end{document}   Therefore, I tried to increase the density of the dotted lines in the global TOC, by adding the following titletoc style declarations after \begin{document}:  \titlecontents{section}[3.8em]{}{\contentslabel{2.3em}}{\hspace*{-2.3em}}{\titlerule*[0.25pc]{.}\contentspage}{} \titlecontents{subsection}[6.2em]{}{\contentslabel{2.9em}}{}{\titlerule*[0.25pc]{.}\contentspage}{}   However, in this case, the hyperref links are changed, which I would like to avoid (no I am not a maniac...). Is there a way to achieve this ? And can this also be used to make the hyperref links in the partial TOCs include the labels ?  And as a subsidiary question, how do I assign the same style to entries in the List of Figures and List of Tables ?  Thank you for your help


How to download Ubuntu 10.04 (Lucid)'s repository?

Since Lucid's packages where moved from archive.ubuntu.com to old-releases.ubuntu.com I'm a bit worried about availability of the repository and want to provide a full local mirror.  Are you aware of a way to download the whole Ubuntu package repository (lucid, lucid-backports, lucid-security and lucid-updates) other than wget -r? I cannot connect with rsync or ftp to old-releases.ubuntu.com.  Edit: This question is not a duplicate of  since the question is about how to mirror from old-releases.ubuntu.com without knowing which packages to mirror (otherwise I could have simply used apt-proxy).


Why are salons which serve both genders called Unisex Salons?

Apparently the prefix 'uni' means 'one' and 'bi' means two (or double) So why are salons that caters to both sexes called unisex?  Flowers which are both male and female are called bisexual flowers... So...


Error when using greek symbol in subscript in beamer presentation

I am working on a beamer presentation which will include many mathematical symbols. I use MiKTeX 2.9 and the TeXstudio IDE.  I have run into a problem when I attempt to use certain mathematical symbols. Here is a MWE:  \documentclass{beamer}  % Document \begin{document}  \begin{frame}   \begin{itemize}     \item This is normal text     \item This item has a greek symbol: $\alpha$     \item This item uses it as a subscript $C_\alpha$   \end{itemize} \end{frame}  \end{document}   I use \alpha twice, once normally and once in a subscript. However, this only compiles without the third item. If that is included, this produces the error:  !pdfTeX error: pdflatex.exe (file mathkerncmssi10): Font mathkerncmssi10 at 657  not found ==> Fatal error occurred, no output PDF file produced!   I have made a web search for similar error texts and found nothing. I have no idea how to further proceed, and would appreciate any hints at what is actually going wrong.  Update 1  It seems this is not related to the \alpha symbol at all, but instead just caused by any letters I try to typeset in mathmode. Including  \item $a$   already causes this error and fails to produce any output document.


Consider:  $ find . -name *.css ./style.css ./view/css/style.css  $ ls view/css/ consultation.css  jquery.scombobox.min.css  page-content.css  style.css   Why might find have missed the files in view/css? This is on Ubuntu 15.10, an obscure Debian derivative.


I attempt calculate this expression: $$\cos\dfrac{\pi}{5}-\cos\dfrac{2\pi}{5}$$ Please, help me, somebody. Thanks.


Cross Product of vectors in 7 Dimensions

While reading a geometry book I came across something like....... Cross Product is possible only in 3 Dimension system and 7 Dimension system. Why?(or How?)


Normalizing a truncated normal distribution

If I have a normal distribution $X\sim N(\mu, \sigma)$, but I want to truncate it at 0, so that for all values below 0, the density is equal to 0 (like the blue density on the left plot below):  The density would be the truncated normal distribution:  I'm unsure how to calculate the pdf for the situation where $a=0$ and $b=\infty$.


Why did Professor X smile before being killed by the Phoenix?

In the  where Professor X and Magneto go to Jean Grey's house after she woke up and escaped, he says something like      Do not let it control you.   Then, Wolverine manages to open some door, and makes eye contact with Professor X. Professor X smiles at him, and is killed.  Why the smile? Did it have a deep meaning? Or was it just death acceptance?


What are the conditions of applicability of linear regression?

I am looking for a list of "Conditions of applicability of linear regression" to finish a work, but I cannot find any reference of this in any book.  I founded something in several links, but in one of this the conditions are 5, in another 4, in another 10, so I am not sure what are the correct list of "Conditions of applicability of linear regression"  Thanks.


Mojave - disabling trackpad from terminal

I tried to disable trackpad on my MacBook Pro 2015 my operating system is Mac OS X Mojave there is not have Accessability menu in System properties. So, how to disable it from Terminal?


What causes this to happen to Luke in TLJ?

Near the end of The Last Jedi, after       astral projecting himself to the battlefield and allowing the rebels to escape, Luke just disappears, causing his body to disintegrate.    As far as I know, this isn't a side-effect of "too much force usage", so what is the actual cause of      his conversion (presumably) to the Force?    I understand from a purely plot perspective, it could be argued that      he intentionally converts in order to provide more "power" to Ray (for lack of a better word), as the Force keeps balance and would provide either Kylo Ren with enough power to match both Luke and Ray, or would send something over to the Dark side as an equalizer. This explanation however does not seem to show us why he disintegrates unless by choice, which given the timing seems like a bit of an odd choice to make as we don't have hard evidence that Ray has been fully trained in not only fighting with a lightsaber, but also in basics of how the force works.   I just want to know how it worked in the movie, so please only canonic sources.  Note: The linked duplicate asks how he astral projects himself, which I am not questioning in this. I'm asking closer to       what was the cause of his disappearance, seeing as we've never seen a "running out of Force power" as an actual side-effect of using the force.


sensing the existance of the AC power line

I have more than one AC power source and I want to detect which one of them is ON which one is OFF using a Microcontroller. So my question here is what is the cheapest and smallest in size method to detect whether an AC power line is there or not?   From 100~240 VAC to 3.3V Steady DC


function and getElementById not working in Javascript

I have created a page where if the input length is 0, it shows an alert. And if input length is not 0, it does the function that href"mailto:info@company.com" property does(Did it with document.getElementByID). I want that after clicking on Send button, it sends an email or does the function that Html's href"mailto:info@company.com" property does. But it is not working. The code is: HTML: <form action="index.html">    <input type="submit" class="btn" value="Send" onClick="auth(event)">

 </form>  JavaScript:     function auth(event) {   event.preventDefault();    var username = document.getElementById("username").value;    if (username.length === 0) {     alert("Please enter your email");     return;   } else if (username.length === 5) {     document.getElementById("SendMail")   }    }


Symbol for "corresponds to" (equals sign with hat)

Recently in some LaTeX documentation I noticed that there is a special LaTeX command for the symbol meaning "corresponds to", which is similar to an equal sign with a hat on top. \hat{=} or \widehat{=} both do not give satisfying results (my personal view). Unfortunately, I cannot remember which documentation it was! Does anyone know the command or the documentation where to find it?   The symbol I am looking for:    PS: I have already tried  but it didn't produce anything useful! Also, browsing  wasn't successful.


The way to earn the 'Analytical' badge is: Visited every section of the FAQ (retired). What does (retired) mean? Does it mean that it is no longer available?


I want to add 30 days to today date and here how i tried Thanks in advance!  var date = new Date();     document.getElementById("demo").value = (date.getMonth() + 1) + '/' + date.getDate() + '/' + date.getFullYear();


How do I install the Nvidia driver for a GeForce GT 630

I recently installed 14.04.  But now I need a new driver for my nVidia GeForce GT 630. The former driver was rejected as not compatible with the 64-bit. I found that other driver and when I wanted to install it in the terminal with sh I was called first to stop the x-server. It cannot be installed with running x-server.  So how do I install them?


As the title already indicates, I have a problem with the page numbering.  At first I am in roman numbering mode and then I switch to arabic. But even though my \pagenumbering{arabic} statement is after my \listoftables command, the list of tables has the pagenumber 1.  \documentclass[10pt,a4paper,headsepline,footsepline,DIV13,BCOR12mm]{scrbook} \usepackage[english,ngerman]{babel} \usepackage[T1]{fontenc} \usepackage[latin1]{inputenc} \usepackage{scrpage2} \pagestyle{scrheadings} \usepackage{graphicx} \usepackage{hyperref} \usepackage[toc,numberedsection]{glossaries} \makeglossaries \newacronym{fap}{FAP}{Fundamental Architectural Principles}  \begin{document}  \selectlanguage{ngerman} \thispagestyle{empty}  \begin{table}[h] \centering \begin{tabular}{ccc} \hspace{0.7cm} & \end{tabular} \end{table}  \vspace{8mm} \begin{center} {\Large {\bfseries \scshape Institut Software \&  Engineering}\\  6a \hspace{0.25cm} D- \\ } \end{center}  \vspace{1cm} %title \begin{center} {\Huge \bfseries asd  \\[2mm] in   \\[5mm] asdasd } \end{center}  \vspace{1.5cm} %author \begin{center} {\Large Christian Vaas} \end{center}  \vspace{1cm} \begin{center} {\Large \bfseries Masterarbeit  Software Engineering} \end{center}  \vspace{1cm} \begin{center} \includegraphics[width=.4\linewidth]{img/logos/LogoSEengl} \end{center}  \newpage \thispagestyle{empty} \mbox{} \newpage \thispagestyle{empty}  \begin{table}[h] \centering \begin{tabular}{ccc} \hspace{0.7cm} & \end{tabular} \end{table}  \vspace{1cm} \begin{center} {\Large {\bfseries \scshape Institut Software \& Systems Engineering}\\  6a \hspace{0.25cm} D- \\ } \end{center}  \vspace{2.5cm} %title \begin{center} {\Huge \bfseries  Patterns \\[2mm] in   \\[5mm]  Architectures} \end{center}  \vspace{1cm} %author \begin{center} \begin{table}[h] \centering \begin{tabular}{ll} Matrikelnummer: &  \\ Beginn der Arbeit: & XX.\ X. XXX 20XX \\  Abgabe der Arbeit: & XX.\ X.XXX 20XX \\ Erstgutachter: & Prof.\ Dr.\ \\ Zweitgutachter: & Prof.\ Dr.\ YYY YYYYYY \\ Betreuer: &  S.  \\ \end{tabular} \end{table} \end{center}  \vspace{1.25cm}  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%% Statement-Page \newpage \thispagestyle{empty} \mbox{} \newpage \thispagestyle{empty}  \centerline{\bfseries ERKLAERUNG}  \vspace{5cm} Hiermit versichere ich, dass ich diese Masterarbeit selbstaendig verfasst habe. Ich habe dazu keine anderen als die angegebenen Quellen und Hilfsmittel verwendet.  \vspace{1cm} \begin{flushleft} %select german for formatting the date \selectlanguage{ngerman} Augsburg, den \today \hfill ZZZ ZZZZZZ \end{flushleft}  \newpage \thispagestyle{empty} \mbox{}   \newpage  %select english as language! \selectlanguage{english}  \vspace*{1cm} \section*{\centering Abstract} \vspace{1cm}  \paragraph*{CONTEXT}  \pagenumbering{roman}  \tableofcontents \newpage \listoffigures \newpage \listoftables  \pagenumbering{arabic}  \chapter{Introduction} \section{Motivation/Challenges} \section{Approach} Blubber \gls{fap}  \printglossaries  \end{document}


I'm new to ubuntu and i'm having all sorts of problems,   My wifi connection is super slow and intermittent, sometimes it randomly disconnects so I was wondering how do I go about to update the drivers for the adapter?  Also, it keeps blinking when transfering data which I find extremely annoying, I have read and tried diferrent solutions about editing the wlan.conf file and adding options iwlwifi led_mode=1 but it doesn't work for me, and I'm guessing it has something to do with the driver, I feel like i'm missing a line or using a setting for an intels adapter rather than an atheros.  I'm using Ubuntu 14.04 64 bits in a HP Pavilion DV7-1245dx.   *-network                       description: Wireless interface        product: AR242x / AR542x Wireless Network Adapter (PCI-Express)        vendor: Qualcomm Atheros        physical id: 0        bus info: pci@0000:09:00.0        logical name: wlan0        version: 01        serial: 00:24:2b:21:93:d7        width: 64 bits        clock: 33MHz        capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical wireless        configuration: broadcast=yes driver=ath5k driverversion=3.13.0-29-generic firmware=N/A ip=192.168.2.7 latency=0 link=yes multicast=yes wireless=IEEE 802.11bg


One if statement taking precedence over another if, despite it being lower?

I'm trying to make an if statement that would allow the user to exit the program by typing quit. My problem lies in that another if statement I have in the same block, albeit lower down, catching to ensure that the string entered is no longer than 3 characters long (required for the program) and that if statement takes precedence and cancels out the "quit" if statement. What am I doing wrong that is causing this?          System.out.print("Guess #"+numGuess+": ");             guess = input.nextLine();             guess.toUpperCase();         if(guess == "quit" || guess == "QUIT"){             done = true;             System.out.println("You lose.");             display();         }         if(guess.length() != 3){             while(guess.length() < 3){                 System.out.println("Guess too short");                 System.out.print("Guess #"+numGuess+": ");                 guess = input.nextLine();                 guess.toUpperCase();             }             while(guess.length() > 3){                 System.out.print("Guess too long");                 System.out.print("Guess #"+numGuess+": ");                 guess = input.nextLine();                 guess.toUpperCase();             }         }


Bluetooth not working on fresh Ubuntu 17.10

I installed a fresh Ubuntu 17.10 and tested my Bluetooth settings. I have two Logitech X100 Bluetooth speakers. hciconfig -a returns this when I turned on my bluetooth:  hci0:   Type: Primary  Bus: USB         BD Address: E4:A7:A0:56:DC:A8  ACL MTU: 1021:4  SCO MTU: 96:6         UP RUNNING PSCAN ISCAN          RX bytes:15707 acl:0 sco:0 events:2449 errors:0         TX bytes:601048 acl:0 sco:0 commands:2441 errors:0         Features: 0xbf 0xfe 0x0f 0xfe 0xdb 0xff 0x7b 0x87         Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3          Link policy: RSWITCH SNIFF          Link mode: SLAVE ACCEPT          Name: 'Bluemoon Universal Bluetooth Host Controller'         Class: 0x000000         Service Classes: Unspecified         Device Class: Miscellaneous,          HCI Version: 4.2 (0x8)  Revision: 0x100         LMP Version: 4.2 (0x8)  Subversion: 0x100         Manufacturer: Intel Corp. (2)   Now the first issue was, that when I connect to the speakers, it disconnects after a few seconds and it disappears in the audio settings. More strange, the Bluetooth speakers and Ubuntu are still paired (the LED is still on (not blinking) and Ubuntu shows me its connected). In Ubuntu I cannot disconnect the speakers anymore, because I got a timeout for this action (seen in the sys-logs).  So I tried installing Blueman, and it didn't help, so I uninstalled it again. Now I cannot find the first Bluetooth box anymore (it never appears in the scan-list) and I cannot connect to the second speakers (at least, Ubuntu bluetooth can find them). More strange, Ubuntu thinks it connects and pairs with the 2nd speakers, but the speaker itself shows me, nothing happened.  And again, disconnect won't work because Ubuntu receives a timeout.  Any ideas?


Recent achievements shows +1, but nothing listed

I know it corresponds to a downvoted answer deleted, but I have no idea where on the network it is.  (And then it disappears.)  This is a duplicate of  but I want it mentioned separately because it's not just a different count to what's displayed.  Perhaps a solution could be a tooltip that just mentions all network sites with changed reputations in the last seven days, just to give us a hint where to look.


Recently in our team, we had a requirement to paginate a set of content. Where we decided to go with  pagination. i.e.    Fetch the whole content with one DB call  Paginate using jQuery Database table (most likely like a client side pagination)   My concern here is, we are holding the whole object in the memory for pagination which would affect performance.   My alternative here is to hit the database using offset and max for each pagination, here DB hit might be another concern.  So my question here is Which is the best approach for pagination considering performance as the main factor?  Holding the whole content in memory or hitting the DB for each page ?


My bike seems to all of a sudden developed a creaking sound when I pedal. It appears to be there in every gear. Bu t I noticed it appears to only happen when I put pressure on the left pedal. What could it be ?


Do I need a transit visa if I am travelling from Marrakech to Oakland, California, with connections in Oslo, Norway and Barcelona, Spain. I have a 12-hour layover in Oslo and a 2-hour layover in Barcelona. I am a Moroccan passport holder and I am a US permanent resident.


Classical mechanics without coordinates book

I am a graduate student in mathematics who would like to learn some classical mechanics. However, there is one caveat: I am not interested in the standard coordinate approach. I can't help but think of the fields that arise in physics as sections of vector bundles (or maybe principal bundles) and would love an approach to classical mechanics or what have you that took advantage of this.  Now for the questions:   Is there a text book you would recommend that phrases the constructions in classical mechanics via bundles without an appeal to transition functions?   What are the drawbacks to this approach other than the fact that it makes computations less doable? (if it does that)   Are there benefits to thinking about things this way, ie would it be of benefit to someone attempting to learn this material to do it this way?


Can a player give an enchanted item on Xbox One?

I found all info for this question here:   I get an error when typing The following:  /give @p diamond_sword 1 0 {ench:[{id:17,lvl:2},{id:19,lvl:30}]}   The error:     x Line 1, Column 2: Missing '}' or object member name   Can the "component:json" field be used on Xbox One or PC only?


What is the probability to get sum $k$ by throwing a die?

Suppose we start at the number zero, and repeatedly roll a fair $6$-sided die, adding the resulting number to the total. We win if we reach the total $k$, and lose if we overshoot, for example by reaching a total of $k-1$ and then rolling a number greater than $1$. What is the probability to win?


20 hours layover in Paris. Can I get tourist visa on arrival?

I am travelling from Chicago, USA to Hyderabad, India. I have a valid USA student visa on my Indian passport. I requested my booking agent for a 20-hour layover in Paris to visit the city (Been a dream for so long). Do I need a tourist visa before starting my journey or can I get one at the airport?  While coming to the USA two years ago, I had a 16-hour layover in London Heathrow and I got a 24-hour transit visa. I was able to go into the city. Can the same be possible for Paris?


Why has iTunes not found/downloaded all of my purchased songs?

I have just purchased a new Macbook pro and I began to set up iTunes and download my 1000+ songs that I have purchased on iTunes. Upon going through the 'purchased' button on the iTunes store, only 580 songs have been downloaded and iTunes is now telling me there are no more songs to download, though clearly there are still 500+ more songs that I own but cannot find anywhere. Why is this and where can I find the rest of the songs? Thank you


Do I need Turkish transit visa to visit Northern Cyprus?

I am a Palestinian citizen living in lebanon. I am a student (aircraft engineer) in university of balamand and i basically have a paper that confirms this. My question is do i need a visa to enter North Cyprus on easter vacation for like maximum 6 days?last time i traveled with visa but I entered turkey for one day because there was a problem in aircraft so i slept one day in Istanbul which I entered turkey with this visa.in addition, last time i applied  visa to turkey but now i dont have this visa. Therefore,I booked tickets to Northern Cyprus im afraid they wont let me reach ercan because some offices told me i need transit turkish visa. I took ticket transit to adana to reach ercan. I have many friends with my case reached but im afraid.I hope u now understood my explanation.


Null Pointer Exception in copying files from remote

This question is related to the following answer posted by Zon.     I used the following code to copy a folder from remote to local.  public void downloadDir(String sourcePath, String destPath) throws SftpException { // With subfolders and all files.     // Create local folders if absent.     try {         new File(destPath).mkdirs();     } catch (Exception e) {         System.out.println("Error at : " + destPath);     }     sftpChannel.lcd(destPath);      // Copy remote folders one by one.     lsFolderCopy(sourcePath, destPath); // Separated because loops itself inside for subfolders. }  private void lsFolderCopy(String sourcePath, String destPath) throws SftpException { // List source (remote, sftp) directory and create a local copy of it - method for every single directory.     Vector<ChannelSftp.LsEntry> list = sftpChannel.ls(sourcePath); // List source directory structure.     for (ChannelSftp.LsEntry oListItem : list) { // Iterate objects in the list to get file/folder names.         if (!oListItem.getAttrs().isDir()) { // If it is a file (not a directory).             if (!(new File(destPath + "/" + oListItem.getFilename())).exists() || (oListItem.getAttrs().getMTime() > Long.valueOf(new File(destPath + "/" + oListItem.getFilename()).lastModified() / (long) 1000).intValue())) { // Download only if changed later.                 new File(destPath + "/" + oListItem.getFilename());                 sftpChannel.get(sourcePath + "/" + oListItem.getFilename(), destPath + "/" + oListItem.getFilename()); // Grab file from source ([source filename], [destination filename]).             }         } else if (!".".equals(oListItem.getFilename() || "..".equals(oListItem.getFilename())) {             new File(destPath + "/" + oListItem.getFilename()).mkdirs(); // Empty folder copy.             lsFolderCopy(sourcePath + "/" + oListItem.getFilename(), destPath + "/" + oListItem.getFilename()); // Enter found folder on server to read its contents and create locally.         }     } }   But I am getting a null pointer exception at the following line which I am unable to resolve.  Vector<ChannelSftp.LsEntry> list = sftpChannel.ls(sourcePath); // List source directory structure   I get that it has problem reading the source path but why? Please suggest.  Edited:  This is the stacktrace:  Exception in thread "main" 4:      at com.jcraft.jsch.ChannelSftp.ls(ChannelSftp.java:1720)     at com.jcraft.jsch.ChannelSftp.ls(ChannelSftp.java:1526)     at org.gradle.CopyTest.downloadDir(CopyTest.java:68)     at org.gradle.CopyTest.main(CopyTest.java:97) Caused by: java.lang.NullPointerException     at com.jcraft.jsch.ChannelSftp.ls(ChannelSftp.java:1543)     ... 3 more   This exception is getting thrown:           throw new SftpException(SSH_FX_FAILURE, "", (Throwable)e);   From this statement I believe:  ((MyPipedInputStream)io_in).updateReadSide();


Using "Material Preview" HDRI in Renders?

I know that I can use default HDRI maps in Rendered mode in Blender right now, but the problem is when I wan to render the image by F12 (or render movie), my settings are changed to use "scene world". Is there a hidden button somewhere in rendering tab or somewhere else? If I have HDRI correct in rendered mode, why I can't have the same result after F12 render?


Activating my locked iPhone after wrong passcode

I can't use my iPhone any longer after my son wrongly entered my passcode to unlock my phone and I am finding it difficult to activate it after his action. How can I get it working again?


I'm new to MySQL, I've created my first data driven website but have some questions about how to best structure it for multiple users.   To explain: The website allows companies to keep track of promotions they are offering. Many companies will use the website and from each company there will be many promotions and many users. The database will contain several table describing the products being offered, sales data etc.  Assuming they successfully login,I assume it's best for each company's info to be stored in separate databases, I see three options for how to structure the data:   Should I also have a distinct database for each promotion?(This will lead to a very large number of databases). Would it be better to only have a single database with data from all promotions appended within the same tables and distinguished the records with a column describing the promotion id? (This strikes me as the simplest conceptually, however, with this approach the tables would become large, and when the user sorts the tables they will have to sort data from all promotions even though they are only interested in a single promotion) Or should I have a single database and create separate tables for each promotion, perhaps by adding the promotion name as a suffix.(This will lead to a very large number of tables within the database over time as each company may have 100 promotions a year).   Sorry for the long question, any help appreciated.  Thanks


Approximate distribution of product of N normal i.i.d.? Special case μ≈0

Given  $N\geq30$ i.i.d. $X_n\approx\mathcal{N}(\mu_X,\sigma_X^2)$,  and $\mu_X \approx 0$, looking for:   accurate closed form distribution approximation of $Y_N=\prod\limits_{1}^{N}{X_n}$ asymptotic (?) approximation of same product    This is a special case $\mu_X \approx 0$ of a more .


Fix LS Colors for directories with 777 permission?

When I run ls on a folder with directories that have a 777 permission, the ls colors are purple text with a green background, which is unreadable:    What can I do to make this more pleasant to look at?


How to get an intuition to draw the eigenvectors for PCA?

For exam preperation I want to know how to get an intuition to draw in the eigenvectors corresponding to the smallest and largest eigenvalue. Student friends say "just get the direction of the largest variance" but I don't quite get it still.   For example for this plot   the first Eigenvector is from the bottom left to the upper right. How would the Eigenvector corresponding to the smallest Eigenvalue look like?  And on the other hand for this plot:    It is (instead of a horizontal line between the both class, which would be my inutitive solution) a line which is horizontal but slightly tilted. How do I get an intuition for this?


If I have multiple pictures that I want as my wallpaper how do I set it that my wallpaper changes say, every 5 min or so? Is there a option like this or must I manually change it?


Hard Science Fiction/ Space Opera about vast wormhole like structure

for the life of me, I can't remember the name or author of this book (or series). In it, there is this huge (infinite) wormhole like structure, that is home to a number of alien species, and can be exited at various points into strange universes etc, and through which the main characters (or some of them) are travelling. It is reminiscent of Baxter, Reynolds, Stephenson, Hamilton, Brin, etc...but if one of those authors, I cannot find the book/s (proabably a series). Any help much appreciated. Not that old, maybe 10 years ago or so (though I could be wrong)


Prevent displayport disconnection when MBP sleeps

I have an external monitor connected by displayport. My issue is, when the display sleeps (after one hour idle), the displayport connection is completely shutdown effectively disconnecting the monitor. When I wake the computer up again, all the windows are re-arranged diabolically on the laptop's built-in display. I use a program called "Stay" to automatically attempt to rearrange the windows how I like them on the external display, but it doesn't always work and I just get irritated by the delay when I need to get back to work. Is there any kind of low-level setting or additional system extension I can use to keep the displayport alive when the computer is sleeping or just energy-saving by turning off the displays? Computer: MacBook Pro (13-inch, 2017, Four Thunderbolt 3 Ports) External monitor:  Adaptor cable:  Issue posted on LG user forum, ignored by manufacturer for 6 months so far:


Where is the right place to start a topic regarding Microsoft certifications?

What site in the Stack Exchange network (meta/SO/programmers) is the best for starting a topic about a Microsoft certification? I'm not after technical assistance - I would like opinions on being 'ready' for the exam etc.


Applying Insufficient Explanation Post Notice to One-line Questions?

Moderators currently have a tool to add a Post Notice that says:     insufficient explanation       We're looking for long answers that provide some explanation and   context. Don't just give a one-line answer; explain why your answer is   right, ideally with citations. Answers that don't include explanations   may be removed.   However, there seems to be no equivalent wording for one-line questions.  Could the wording be changed to something like below to cover both one line questions and one-line answers?     insufficient explanation       We're looking for longer posts that provide some explanation and context.          Don't just ask a one-line question; provide some background like a brief description of your research prior to asking   Don't just give a one-line answer; explain why your answer is   right, ideally with citations.          Questions and answers that don't include explanations may be removed.   Sometimes such questions can simply be closed for being unclear or too broad but on the two sites I moderate there is an aversion to closing questions from new users, so to give them some guidance about what is expected, without spending time writing the same comment over and over, a post notice like this would provide a good "couple of clicks" alternative.


What are the rules about using an underscore in a C++ identifier?

It's common in C++ to name member variables with some kind of prefix to denote the fact that they're member variables, rather than local variables or parameters. If you've come from an MFC background, you'll probably use m_foo. I've also seen myFoo occasionally.  C# (or possibly just .NET) seems to recommend using just an underscore, as in _foo. Is this allowed by the C++ standard?


In relation to , I am curious about what exactly are the normal subgroups of a dihedral group $D_n$ of order $2n$.  It is easy to see that cyclic subgroups of $D_n$ is normal. But I suspect that case analysis is needed to decide whether dihedral subgroups of $D_n$ is normal.  A little bit of Internet search suggests the use of semidirect product $(\mathbb Z/n\mathbb Z) \rtimes (\mathbb Z/2\mathbb Z) \cong D_n$, but I do not know the condition for subgroups of a semidirect product to be normal.  I would be grateful if you could suggest a way to enumerate the normal subgroups of $D_n$ that does not resort to too much of case analysis.


Is there any criteria for voting in any phase of election ? If yes then What eligibility is needed  for vote in election to vote in any or every phase.


Charecters are showing like this "?????" in PHP pdo connection

<?php class dbConnect{ public function __construct() {  global $pdo;   try{   $pdo = new PDO('mysql:host=localhost;dbname=quran','root','');   } catch(PDOException $e){    exit('Database error');   } } } class get_data{  function __construct(){ $connect = new dbConnect(); } public function get_sura_list() {   global $pdo;   $query = $pdo->prepare("SELECT * FROM sura ORDER BY sura_no");   $query->execute();   return $query->fetchALL(PDO::FETCH_ASSOC); } }  ?> <meta http-equiv="content-type" content="text/html; charset=utf-8"><?php $all_sura_list = new get_data();$sura_list = $all_sura_list-> get_sura_list(); foreach($sura_list as $sura){       echo $sura['sura_no'];    echo '-';    $sura_name = rawurldecode($sura['sura_name']);    echo $sura_name;    echo '-';    echo $sura['total_ayat'];    echo '
';   } ?>    Using This Script I'm trying to listing data from my database. non-English Charecters are showing Like this "???????".  I have some non-english charecter in my Database like this "ফাতিহা". Using this script they are showing like this '??????'.   I Used  This code in HTML Head but nothing happend.  How Can I show thoes non-english words properly?


How is it possible to save the vim file without to close it? I do a change, save it immediately and continue to work with the file without to reopen it again... I have found of course the question , anyway the proposed solutions close the file after the job execution.


I got diff text from  how do I patch it into a kernel source? I am using debian


I recently had Linux Mint running as my sole OS, which I later decided to remove to reinstall Windows 8. Windows Update is current, however after the installation I found some missing functionality (USB ports, FN Keys, etc.).  I want my computer to run as if I just bought it. Is there a one-stop shop to ensure that all of my Windows drivers are up-to-date?


Why didn't the hotel's angels become real?

In , the Doctor and his companions encounter      two weeping angels, that are merely illusions and therefore discarded as harmless.   However, back in , it was established that      "That which holds the image of an Angel becomes itself an Angel".   So, why didn't they become real, or probably more correctly, why didn't the hotel or at least the room effectively become one?


Where can I find Dogmeat after dismissing him to Sanctuary Hills?

I recently dismissed Dogmeat in favor of Codsworth, and I'm fairly sure I sent him to Sanctuary Hills. However, I've had a fairly detailed look around the place and I haven't found him yet. Does anyone know where he is?


Proving : $A \cap (B-C) = (A \cap B) - (A \cap C)$

I have proved this using Venn diagram but when I am trying to prove this using the rule that "If $ A \subset B \text{ and } B \subset A $ then $ A = B $", I am having some problems with my understanding of the same,here is how I  did so far:  Let $x \in A \cap (B-C) \Rightarrow x \in A  \text{ and }  x \in (B-C) \Rightarrow x \in A \text{ and } (x \in B \text{ and } x \notin C)  $  How to proceed next? Since if I am do something like this: $ x \in A \text{ and } x \in B \text{ and } x \in A \text{ and } x \notin C $, it's not giving the correct results, what exactly I am missing here?


Can I find out which tags I have created? This would be interesting to know.  The tags could be highlighted on the users page for example.


What is a canonical way to find the actual maximum argument list length?

Following  it seems like ARG_MAX is wrongly (or at least ambiguously) defined on my Mac Mini 3,1 running Ubuntu 12.04:   $ getconf ARG_MAX # arguments  2097152 $ locate limits.h | xargs grep -ho 'ARG_MAX[ \t]\+[0-9]\+' | uniq | cut -d ' ' -f 8 131072   The actual limit seems to be somewhere between these:  $ cd "$(mktemp -d)" $ touch $(seq 1 131072) && find . -mindepth 1 -printf x | wc -c && rm * 131072 $ touch $(seq 1 131073) && find . -mindepth 1 -printf x | wc -c && rm * 131073 $ touch $(seq 1 $(getconf ARG_MAX)) && find . -mindepth 1 -printf x | wc -c && rm * bash: /usr/bin/touch: Argument list too long   I did a small search:  cd "$(mktemp -d)" min=131072 max=2097152 while true do     search=$((min + (max - min) / 2))     if touch $(seq 1 $search) 2>/dev/null     then         min=$search     else         max=$search     fi     [[ $((max - min)) -le 1 ]] && echo "ARG_MAX = $min" && break done   Eventually this resulted in ARG_MAX = 314290, which doesn't seem to have any relation to either of the ARG_MAX values found before. Is this normal? Is there a simpler way to find the actual ARG_MAX?  Did I misunderstand the definition of ARG_MAX? It seems it's actually the  (or possibly character) length of the arguments with or without (?) the separating spaces. If it's really the byte length, are there also ?


How do I prevent an Ice from freezing in faction base walls?

I made a huge base from bottom to the top I also made walls it almost finished I need water to protect it from TNT but how do I stop it from freezing the water?  Someone did there's duplicate of this question IT'S NOT there's nothing about on faction bases like on walls


Is openssl rand command cryptographically secure?

I'm wondering if the openssl rand command produces cryptographically secure random bytes. For example when in need for a random password or token:  openssl rand -hex 32   The man page unfortunately does neither state it's cryptographically secure, nor that it's not.  On the one hand, I think this is openssl, its sole purpose is to do cryptography. On the other hand, the man page states something about reading and writing seed data instead of directly querying a CSPRNG.  So it is somewhat unclear for the end user. Does someone know?


Why does the action $S=\int L dt=\int (T-V) dt$ have to be minimised (or maximised) to produce Newton's Second Law?

We have recently covered the Lagrangian in our lectures, whereby it was shown that all equations of motion ($x(t)$) satisfying the Euler-Lagrange equation with Lagrangian $L=T-V$, where $T=\frac{1}{2}mv^2$ and $F=-\frac{\partial V}{\partial x}$, must also satisfy $F=m\ddot{x}$.  However, to me, it wasn't intuitive at all why this must have been the case: why, if we minimise (or maximise) some arbitrary quantity $L$, which didn't even have to be conserved, we for some reason get Newton's Second Law, which also implies that $L$ is in fact energy and has to be conserved.  Is there any intuitive way of understanding why ALL possible types of motion MUST minimise this arbitrary quantity $S$ and why, if we do minimise it, we get that $L$ is conserved and happens to represent the total energy of an object?


Cannot find results of MakeFeatureLayer, cannot use SelectFeatureByAttribute

I have a goal: take a feature class, select some of the records by attribute, and make a layer for further processing. Should be simple, but I am having multiple problems. Note: I am working in a Python 2.65/ArcGIS 10 environment (may be cause of some of these issues). I start with my gdb   master_dict = {'Alabama': ['01009', '01013'], ...}  statePath = "<...>/gdb/master_merge_footprints.gdb"   I want to iterate through the gdb and find specific features based on state names. This part works. I can even print the fields just to test that the feature class exists:   stateNames = ['Alabama', 'Alaska'...]  for name in stateNames:      arcpy.env.workspace = statePath     featureclasses = arcpy.ListFeatureClasses()     fip_merge_list = []     for fc in featureclasses:         if name in fc:             print fc             fipslist  = (master_dict[name]):             for fip in fipslist:                  ### Here's where the problem occurs   Here is where the problem occurs. As I mentioned if I've tried several things to make sure that fc exists,  including fieldnames = [field.name for field in arcpy.ListFields(fc)]. I am able to print the field names and verify that the field for the where clause also exists. I create a hard output path to an existing gdb just to make sure the process will work. When I run this however, nothing shows up in my gdb when I check in ArcMap. I can manually run a selectByAttributes function in ArcMap directly on this fc as well.   select = arcpy.MakeFeatureLayer_management(fc, statePath + "/%s_temp_lyr_%s"%(name, fip),"FIPS_CODE = '%s'"%(fip))   The process runs and doesn't throw an error, but nothing is showing in my gdb. So I tried just using the SelectLayerByAttributes_management with fc and it throws an error:  select_1 = arcpy.SelectLayerByAttribute_management (fc, "NEW_SELECTION", "FIPS_CODE = '%s'"%(fip))      Traceback (most recent call last):   File "", line 1, in          select_1 = arcpy.SelectLayerByAttribute_management (fc, "NEW_SELECTION", "FIPS_CODE = '%s'"%(fip))   File "C:\Program Files   (x86)\ArcGIS\Desktop10.0\arcpy\arcpy\management.py", line 4259, in   SelectLayerByAttribute       raise e ExecuteError: Failed to execute. Parameters are not valid. The value cannot be a feature class ERROR 000840: The value is not a   Raster Layer. ERROR 000840: The value is not a Mosaic Layer. Failed to   execute (SelectLayerByAttribute).   So, I can't make a layer from my feature class, I can't select by attributes, and I am stuck. I have manually verified that the feature class exists (both in Python and ArcMap), I have verified that the field exists, and I have verified that the fip exists. Any advice on what I am doing incorrectly here?


Combining two arrays without the repetition

My goal is to find places in the chess board where I can put a figure of a king. I can put max. two towers in a row and/or a column. I cannot put king in a row or a column where any tower appears. Input is a matrix nxn with '1's (places where I put towers). Output: coordinates where I can put a king. Matrix with towers is not generated automatically.  Really important: I cannot use any loop  My question is: how to combine two arrays together to have such pairs: in:[2, 3, 4] and [1, 3, 4], where 1st array is a row, 2nd is a column out: [2, 1], [2, 3], [2, 4], [3, 1], [3, 3], [3, 4], [4, 1], [4, 3], [4, 4]  import numpy as np a = np.matrix([[1, 0, 0, 0, 0], [0, 0, 1, 0, 1], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 1, 0, 0]]) print(a) print('*for 0*') y = np.argwhere(a == 0) z = np.argwhere(a == 1) rowsy = np.unique(np.array(y[:,0])) print('rows where 0 appears') print(rowsy) colsy = np.unique(np.array(y[:,1])) print('columns where 0 appears') print(colsy) print('*for 1*') rowsz = np.unique(np.array(z[:,0])) print('rows where 1 appears') print(rowsz) colsz = np.unique(np.array(z[:,1])) print('columns where 1 appears') print(colsz) print('**') print('diff between rows:') r0 = np.setdiff1d(rowsy, rowsz) print(r0) print('diff between columns:') r1 = np.setdiff1d(colsy, colsz) print(r1) print("**")   shortened version:  import numpy as np a = np.matrix([[1, 0, 0, 0, 0], [0, 0, 1, 0, 1], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 1, 0, 0]]) y = np.argwhere(a == 0) z = np.argwhere(a == 1) rowsy = np.unique(np.array(y[:,0])) colsy = np.unique(np.array(y[:,1])) rowsz = np.unique(np.array(z[:,0])) colsz = np.unique(np.array(z[:,1])) r0 = np.setdiff1d(rowsy, rowsz) r1 = np.setdiff1d(colsy,colsz)   I know it's very general solution but to finish this I need just to combine those last arrays r0 and r1


C# - Collection was modified; enumeration operation may not execute

There's a  button click event in a lengthy code I've written. I have a list of objects in it. Each time the button is clicked, the list should be modified ( for example, some items should be removed ) and then iterated using a foreach loop.  List<Person> lp=new List<Person>(); lp.RemoveAt(2);  foreach(Person j in lp) {     // do something }   When I try to execute the above code, it results in an exception.  InvalidOperationException : Collection was modified; enumeration operation may not execute.  I found some solutions on the internet and tried them. One of them is,  foreach(Person j in lp.ToList()) {     // do something }   But nothing could stop the exception.  can someone help with this ?


I found these "things" by chance on my wild strawberries which I grow in my organic garden. Basically, some strawberries are completely covered with them.    They're transparent, they have dots equally aligned and they don't move. I've tried searching for transparent slugs and worms and also faeces but to no avail.


Why don't we study algebraic objects with more than two operations?

Undergraduates learn about algebraic objects with one operation, namely groups, and we learn about algebraic objects with two "compatible" operations, namely rings and fields. It seems natural to then look at algebraic objects with three or more operations that are compatible, but we don't learn about them. I asked one of my professors why this is so and she posed this question in response: we have left-modules and right-modules, but there are no top-modules or bottom-modules, or any other ways of combining two elements to produce a third. I can't think of any satisfactory answer to either of these questions. Can anyone shed any light on them?  Edit: Now that I know these objects are studied, what I meant by "we" is essentially "Why are these objects not introduced to undergraduates (at least in a standard curriculum) given how natural they seem?"


Is the 75% code coverage requirement to deploy to production per class or overall?

My developer org's overall code coverage is 76%, but some classes are still 0% while others are 100%.  Will I be able to deploy all my code or does Salesforce require a 75% coverage per class?


JSLink (js)file is updated, but still can't see any changes, maybe caching?

I am using SharePoint 2013 online (Office 365). I am following some JSLink tutorial where I am showing indicator icons in columns. It looks like the .js file is working, but when I change the file and check it in, I don't see any changes.   I have created a custom list with a column with choices : Green, Red, Yellow. After this I created a page and added this list as a webpart.   On this webpart I have set a path of my .js file. In this .js file there is some logic where the control is overridden with an icon. I see a broken image. I did some changes in my js file, but I still see the old path of the image. Is there some caching in SharePoint which is using the js file??  This is the tutorial:


Upper bound on $\chi(G)$ for a triangle-free graph

I'm struggling with the following question;     For every graph $G$ such that $K_3 \not\subseteq G$ (i.e. $G$ does not contain a triangle), prove that $\chi(G) \leq 2\sqrt{n} +1$ (where $\chi(G)$ denotes the chromatic number).   Any hints? I really cannot see the connection between the triangle-free nature of $G$ and a chromatic number being bounded above by $O(\sqrt{n})$.


How to remove restrictions in latest IOS?

This is probably a duplicate, but the &@$#& app won’t let me scroll through the suggestions.  I keep getting “page is restricted” in Safari for pages that are obviously quite innocent.  (Some of them confirmed so by checking on laptop.)  Multiple web pages say Settings: General: Restrictions, but there is no such path in IOS 12.1 and I have so far failed to find anything anywhere in settings.  Checked Privacy, Safari, and several other places.  One of those pages claimed to be telling us that it was for IOS 13.


Smooth Approximation of Staircase Function

What is a function $f(x)$ that is smooth and approximates a staircase function (a function composed of a set of equally spaced jumps of equal length)?  With , I know of $f^n(x)$, where n is an integer and $f(x)=x-\sin(x)$, but it requires quite a large amount of terms to get to a desired sharpness. So, I'm looking for approximations that is not recursive and requires only a finite amount of terms.


How do I merge the the two values of two objects that share a common key together and return it?

Write a function called mergeCounters which accepts two objects where all of the values are numbers and returns a new object with the total of both objects. The order of your returned object does not matter, as long as it contains the correct keys and values!   function mergeCounters (object1, object2) {   var myObj = {};   for (key in obj1) {     for (key2 in obj2) {       var val = myObj[key + key2];     }   }   return myObj; }  var obj1 = {a: 1, b:2, c:3}; var obj2 = {a: 3, b:6, c:7}; console.log(mergeCounters(obj1, obj2)); // {a:4, b:8, c:10}  var obj3 = {a: 1, c:3, d:5}; var obj4 = {a: 3, b:6, c:7, z:20}; console.log(mergeCounters(obj3, obj4)); // {a:4, b:6, c:10, d:5, z:20}


I need to update incremental code in a custom field on accounts so that if user changes the Type then no. should be incremented by 1

I need to update incremental code in a custom field on accounts. So that, If user changes the Type from Prospect to customer then no. should be incremented by 1.  For example:   For account1, it will be C1 For account2, it will be C2 For account3, it will be C3   Whenever user changes the type from Prospect to Customer, It will pick the last no. of previous record and then it will increment. Code will be unique for each account as we need to use the same code for integration purpose.


How can I see which application is using Bin, so that it cannot be emptied?

How can I see which application is using the Bin, so that it cannot be emptied?  I've so many tasks and projects open, so I'd rather not restart the macOS Catalina.  I have tried looking in Activity Monitor, but couldn't figure it out.


Great Weapon Master Critical Hit Resolution

My apologies if my unfamiliarity with the rules makes this an easy question to answer...  I am considering taking Great Weapon Master, but was curious how this would affect my critical hits. I am currently a level 20 Half-Orc Barbarian, meaning that when I land a crit, I can add a bunch of extra damage dice (I believe I am able to add 3 extra dice from Brutal Critical, and Savage Attacks allows me to add another extra die).  However, how are critical hits affected by Great Weapon Master? If I take the -5 penalty before rolling, and then roll a nat 20, will the critical still hit, AND will I then get to add the extra +10 to damage dealt? Or would the roll become a 15, thereby negating the critical hit altogether?   states:     Before you make a melee attack with a heavy weapon that you are proficient with, you can choose to take a -5 penalty to the attack roll. If the attack hits, you add +10 to the attack’s damage.   This becomes even more important given the other feature of Great Weapon Master:     On your turn, when you score a critical hit with a melee weapon or reduce a creature to 0 hit points with one, you can make one melee weapon attack as a bonus action.   So how does Great Weapon Master affect critical hits?


Identifying a children's fantasy book series (gem-based powers, sea monsters attacking tower)

There's this children's fantasy series I've been trying to find for years from one book I've read in my youth. From what I recall it was a long-ish series (7-8 books?) and I believe that the powers in the books were based on gems, or some kind of stones. I read this series about 8-7 years ago and it was finished by then - hopefully that gives a rough time period for people to pin it too.   I know the one book I read was either the last or near last book in the series, and the only part of the plot I can vividly remember were incredibly large sea monsters arriving from the ocean/sea to attack some sort of...tower? I believe there were also illustrations of these monsters (though I'm not sure if I'm not just mistaking those illustrations for my imagination).  I think I also recall a segment about a character trying to escape some sort of mine, where there were Underseers/Overseers, though that may not have been in this same book (I don't remember if I only read one or two books of the series, haha). I also remember there being some sort of love story if that's any help (probably not).  Sorry this is so vague, and I hope someone can give me an answer eventually! It's been really bugging me, and I can't seem to find any series like it anywhere.


There are 2 ways to create a thread in the Java language, one is by implementing 'Runnable' and the other is by extending the 'Thread' class. In the book I am reading (Herbert Schildt), It's written that implementing the 'Runnable' interface is better, they have duly provided the reasons but I couldn't understand. Could anyone elucidate why there are 2 methods of creating a thread in java and why implementing the interface is a better solution?


How can I use ffmpeg to output a screenshot gallery / mosaic?

I am wondering how to use ffmpeg to create video thumbnails something like this (taken from a VLC forum):  I know totem can do this but totem does not support the video format that I am using  says that ffmpeg can do it.


I first noticed it during an interview a journalist was doing with a presidential candidate. The journalist asked questions. Each time the candidate started his answer with the word "so". Now I am hearing this strange usage everywhere. It is as though the word "so" is replacing "um" and "uh" or something. I'm no linguist. My punctuation and sentence structure is probably pedestrian at best. However, this use of "so" is getting out of hand.  "What did you do today?"  "So, I walked the dog."  Also starting to see, "Okay, so..." and "sure" thrown in too.  Is "so" the elite form of "like"?


Part of my object disappears In camera view

Hi newbie in blender here.   does anybody know how to solve the problem?   Outside view show the whole 3d model, but on camera and rendered it comes out like this:


I don't know how to solve the following:  Let $(x_n)_{n=1}^\infty$ be a sequence with property $\sum_{n=1}^\infty |\frac{x_n}{n}|<\infty$. Find a limit $\lim_{n\to\infty}\frac{x_1+x_2+\dots+x_n}{n}$.  Any hint is welcome. Thanks in advance.


I have these 2 command lines that I use very frequently First: ps xw, the output will look something like this     PID TTY      STAT   TIME COMMAND  670571 ?        Ss     0:00 /lib/systemd/systemd --user  670572 ?        S      0:00 (sd-pam) 2398632 ?        S      0:00 sshd: ubuntu@pts/0 2398643 pts/0    Ss     0:00 -bash 2398864 pts/0    Sl     0:03 ./main 2757354 pts/0    R+     0:00 ps xw  Then I copy the PID of ./main and run the 2nd command, in this case it is: kill 2398864. Is there any way I can combine these 2 commands together so that I don't need to copy the PID every time?


How to fix "AWT-EventQueue-0" java.lang.NullPointerException when using audio files

So I am creating an application that plays audio-files in the background using clips() and I added a JSlider that allows the user to alter the volume of the audio-file. However, whenever I click the JSlider it gives me the following errors:   Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException at GoRacer.stateChanged(GoRacer.java:764) at javax.swing.JSlider.fireStateChanged(Unknown Source) at javax.swing.JSlider$ModelListener.stateChanged(Unknown Source) at javax.swing.DefaultBoundedRangeModel.fireStateChanged(Unknown Source) at javax.swing.DefaultBoundedRangeModel.setRangeProperties(Unknown Source) at javax.swing.DefaultBoundedRangeModel.setValueIsAdjusting(Unknown Source) at javax.swing.JSlider.setValueIsAdjusting(Unknown Source) at javax.swing.plaf.basic.BasicSliderUI$TrackListener.mousePressed(Unknown Source) at java.awt.Component.processMouseEvent(Unknown Source) at javax.swing.JComponent.processMouseEvent(Unknown Source) at java.awt.Component.processEvent(Unknown Source) at java.awt.Container.processEvent(Unknown Source) at java.awt.Component.dispatchEventImpl(Unknown Source) at java.awt.Container.dispatchEventImpl(Unknown Source) at java.awt.Component.dispatchEvent(Unknown Source) at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source) at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source) at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source) at java.awt.Container.dispatchEventImpl(Unknown Source) at java.awt.Window.dispatchEventImpl(Unknown Source) at java.awt.Component.dispatchEvent(Unknown Source) at java.awt.EventQueue.dispatchEventImpl(Unknown Source) at java.awt.EventQueue.access$500(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source) at java.awt.EventQueue$4.run(Unknown Source) at java.awt.EventQueue$4.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source) at java.awt.EventQueue.dispatchEvent(Unknown Source) at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.run(Unknown Source)   My code for my audio-player method is:    public void musicPlayer (String filePath, String loopYesNo, float userInput, long position, Clip a){   try{   File fileSong = new File (filePath);    AudioInputStream input = AudioSystem.getAudioInputStream(fileSong);    a = AudioSystem.getClip();   a.open(input);    a.setMicrosecondPosition(position);     FloatControl gainControl = (FloatControl) a.getControl(FloatControl.Type.MASTER_GAIN);    float range = (float) (Math.log(userInput) / Math.log(10) * 20);    gainControl.setValue(range);    a.start();      if (loopYesNo.equals("Yes")) {     a.loop(Clip.LOOP_CONTINUOUSLY);   }  } catch (Exception error) {   errorEnd();  }   }  And the code for the JSlider is:     public void stateChanged (ChangeEvent e) {   if (e.getSource() == volume) {    long clipTimePosition = clipMusic.getMicrosecondPosition();    clipMusic.stop();      programVolume =  (float)volume.getValue() / 100;       musicPlayer(mainFrameMusic, "Yes", programVolume, clipTimePosition, clipMusic); }   }  If I get rid of Clip in input parameters it seems to work fine;however, seeing that I will be needing to listen to multiple audio-files in this program it would be nice to use one method for all of them.


Why do I get a "???" error when I try to install Ubuntu 15.04 64-bit?

I am trying to dual-boot Ubuntu 15.04 64-bit on my laptop, a .  I have created a 241 GB partition. The other OS on the computer is Windows 8.1. The installation media was a DVD+R disk connected via USB drive. Secureboot and fast boot were disabled.  When I get to the installation page, I get this screen:  [Image in comment]  When I click continue, it loads for a few seconds and then this comes up:    When explaining what to do, please also explain why this occurs.


Is there a way to log root commands from SSH on OpenVZ Node? I tried Snoopy and I was not able to exclude everything and leave only SSH commands.   @edit I want log ONLY commands sent through SSH/SFTP from remote host, because on my openvz node root is used to run many other commands locally. For example Snoopy is logging everything that happens on system (that is a lot of trash..), but I want to see what is done by any person on root by SSH/SFTP.


Is the XP for an encounter split among the party members or not?

At this point, I am unclear as to how to handle encounter XP. Does each surviving party member receive a proportional share, or the full amount? That is, assume a 4-character party had completed an encounter worth 400 XP. Would each party member receive 100 XP, or 400 XP?


I would like to have footnotes in tables, but the \footnote command does not work inside a table environment.  Googling one finds that this is , at least in the UK.  That link contains a list of solutions to the problem, but since the author of the FAQ does not believe that this is good style, no comparison is made between the different methods.  I am sure that there are good typographical reasons why in most situations it is undesirable to have footnotes in tables (although I have never come across them), however I have recently felt the need to do just this in a paper I am currently writing.  Therefore I'd like to ask two questions:   What are the arguments against footnotes in tables? If one really must go against the advice in 1., which method (whether considered in the  or not) would you recommend?   Thanks in advance.  Added  In response to ShreevatsaR's comment: I do not much care for where the text of the footnote appears.  I do however insist on the footnote marks being attached to the relevant entries in the table, so that I can avoid having to reference "the second entry in the eighth line of the table", etc...


I have to teach about diagonalization of a matrix to a first year undergrad student and I was wondering what would be a good way to motivate this concept. I would appreciate any suggestions. Thanks!


Product of principal ideals: $(a)\cdot (b) = (a b)$

In which kinds of rings $R$ does the following hold:  $$(a)\cdot (b) = (ab) \; ?$$  With $a, b\in R$, $(a)$ denoting the (two-sided) ideal generated by $a$ and the multiplication of ideals $I, J\subset R$ defined as  $$ I\cdot J = \biggl\{\sum_{i=1}^n x_i y_i : n\in\mathbb{N}, x_i \in I, y_i \in J \biggr\}\, .$$  It seems to me that it only holds for commutative rings with $1$. Is that right?  Ok, I'm trying a proof:     Let $R$ be commutative with $1\in R$. Then $(a)\cdot (b) = (a b)$ for any $a, b\in R$.   First let $I_a := \{ra : r\in R\}$, we're going to show that  $$(a) = I_a\, .$$ $I_a$ is obviously an ideal. Since $1 \in R$ we have $1 \cdot a \in I_a$, so $(a) \subset I_a$. On the other hand, any $x \in I_a$ can be written as $x = ra$ and so must be an element of $(a)$. This proves that $(a) = I_a$.  Then $$(a)\cdot (b) = I_a \cdot I_b = \biggl\{\sum_{i=1}^n x_i y_i : n\in\mathbb{N}, x_i \in I_a, y_i \in I_b \biggr\}  = \biggl\{\sum_{i=1}^n (r_i a)  (s_i b) : n\in\mathbb{N}, r_i, s_i \in R \biggr\} = \biggl\{a b \sum_{i=1}^n r_i s_i : n\in\mathbb{N}, r_i, s_i \in R \biggr\} = \biggl\{a b r : r \in R \biggr\} = I_{ab} = (ab)\, .$$  We obviously had to use that $R$ is commutative. In the last step we also used that every $r \in R$ can be written as $r=\sum_{i=1}^n r_i s_i$. This is because $1 \in R$, so with $n=1$ we have $r = 1\cdot r$.


I want to describe: a job-position that is given to someone as a way to appease the person, but the position holds no real function.  Context:     He was, due to his importance to the secret project, offered an honorary ____ with disproportionally lucrative payment.   The job is given by the authority to the person as a way to basically bribe him with undeserved salary, because he won't be given any real task. The emphasis here is payment, and not power, so "figurehead" would be inappropriate.


Prove that {1,sin(x),sin(2x),sin(3x),…,sin(nx)} is an independent set. I received 1 answer 3 days ago but didn't find the answer very clear.  Please advice, thanks!


Is there a way to fall through multiple case statements without stating case value: repeatedly?  I know this works:  switch (value) {    case 1:    case 2:    case 3:       // Do some stuff       break;    case 4:    case 5:    case 6:       // Do some different stuff       break;    default:        // Default stuff       break; }   but I'd like to do something like this:  switch (value) {    case 1,2,3:       // Do something       break;    case 4,5,6:       // Do something       break;    default:       // Do the Default       break; }   Is this syntax I'm thinking of from a different language, or am I missing something?


Is there an unkindly way to say thank you?

Are you not already being kind by saying thank you to begin with?  I read the comments on this site , and I guess that I am still pretty confused as to the meaning of this.    Obviously, if someone says "Thank you" in a very sarcastic manner then they aren't intending to be kind, but I mean in the general sense of showing gratitude to someone for something, is there a way to do this unkindly?  If there isn't a way, then why would someone say, "Thank you kindly"?


How can I keep Opera installed on Ubuntu live USB?

I have a problem my Hard Disk. So I am using a live USB of ubuntu.  For using Opera browser, I am installing it each time I boot. Is there a way to keep this installation after a system reboot with the live CD?  I want not to persiste all the installation of ubuntu on my USB. I want to know if it is just possible to persiste just one software (Opera) ?


Can I acquire a Windows 8.1 licence by free upgrade from 7 to 10, then downgrading

So, I have Windows 7 pro, and I'm looking to upgrade so that I can use some of the apps that are only available in Windows 8+. I considered just taking advantage of the free Windows 10 upgrade, and actually installed it at one point, but then I found out that there's forced automatic updates and decided that wasn't for me(I'm a bit paranoid after Android 4.4.4 killed Flash Player without telling me. :P). So, I did some research.   From what I read, the Windows 10 upgrade "consumes" your Windows 7 license into a Windows 10 license, and so even if you revert back after upgrading then you can still change your mind later and jump back to Windows 10. () I also read that Windows 10 has "downgrade" rights to Windows 8 and Windows 7, which to my understanding meant that if you have a Windows 10 key, you can also use it to install Windows 8 or 7 if you want. ()  My plan for the process is re-upgrade to 10, pull the license key, downgrade to 8 and use the license key, then upgrade to 8.1 via Windows Store, and end up on 8.1. So my questions are: Is this possible?  Will it wipe all my data in the process?(not a dealbreaker if it does, but I'd need to know that so I can back it up) Do I need to re-upgrade to 10 in order to downgrade to 8?  Any input is definitely appreciated. Thanks!


Yes, the books might have been written on this but not being a technical person, I'd like to understand in short and easy to understand language - How to interpret a histogram to know whether the photo is under or over exposed?


Are there alternatives to multiple buffering?

I'm learning about game programming. So far, my sources lead me to believe that  is the best technique for redrawing in OpenGL.  Are there other redrawing techniques? What are their advantages/disadvantages?  I'm not sure about terminology yet, but googling as best as I can hasn't yielded much result yet. Does anyone have any experience with redrawing techniques besides multiple buffering?


Avoid the "You need to format the disk in drive F:" when plugging a TrueCrypt/VeraCrypt external drive

When plugging a USB external hard drive encrypted with VeryCrypt, VeraCrypt detects it and asks for the password (this is expected, and works well thanks to the Favorite Volumes > Mount selected volume when its host device gets connected feature!)...   ... but this message is also displayed: You need for format the disk...    The reason is obvious: the partition is unreadable for Windows, so Windows suggests to format it.  Is there a way to avoid this message on each USB connection of the encrypted external hard drive?


I want get the the position (screen coordinates) of all divs in an iframe using javascript. No jQuery.  I can get all the divs in an array like this:  var arr = window.frames[0].document.getElementsByTagName("div");   Then i tried to do:  var arr = window.frames[0].document.getElementsByTagName("div").x;   But it didn't work. Console logs undefined. Any ideas?


Last week I installed Lubuntu 18.10 on a Dell D630 on a new hard drive. I previously had been using Lubuntu17.04 on this machine, but the hard drive quit working  The Wifi card (Dell 1390--BCM4311) didn’t work when I first installed 17.04. I looked around on the Internet and found information that told me to remove the STA driver and replace it using  sudo apt-get install --reinstall b43-fwcutter sudo apt-get install --reinstall bw43-fwcutter firmware-b43-installer  This worked fine in 17.04. I decided to try it for 18.10.  sudo apt-get install --reinstall b43-fwcutter [This seemed to work without problems.] sudo apt-get install --reinstall bw43-fwcutter firmware-b43-installer  [Linux response]  Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package bw43-fwcutter  I tried the following  sudo apt-get install firmware-b43-installer  [Linux response]  E: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable) E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?  I then tried:  sudo apt-get update sudo apt-get --reinstall install bcmwl-kernel-source [This appeared to run to a successful completion—no errors or problems came up.]  The instructions I was following then said to enter  sudo modprobe -r b43 ssb wl brcmfmac brcmsmac bcma  This gave an an error message "module ssb in use". I tried rebooting, but the wireless card didn't become operational. Interestingly, some icons on the task bar disappeared.  I removed the bcmwl-kernel-source and rebooted—the icons on the task bar reappeared.  So what next? It looks like the 18.10 repositories don't contain what the 17.04 repositories contained.


I have a custom module already installed, and I am trying to add a new table to the database with hook_update_N(). So, I edited hook_schema() and hook_update_N() in the my_module.install file as below.  function my_module_schema() {   $schema['my_table'] = array(     'fields' => array(       'application_setup_id' => array(         'type' => 'serial',         'not null' => TRUE,         'description' => 'Primary Key: ID',       ),     ),     'primary key' => array('application_setup_id'),   );   return $schema; }  function my_module_update_8601(&$sandbox) {   $spec = array(     'fields' => array(       'application_setup_id' => array(         'type' => 'serial',         'not null' => TRUE,         'description' => 'Primary Key: ID',       ),     ),     'primary key' => array('application_setup_id'),   );   $schema = Database::getConnection()->schema();   $schema->createTable('my_table', $spec); }   I am running drush updatedb to update the database after the changes. No database changes are done.  What am I missing?


Premise Two wizards hold an action to cast fireball on the first humanoid that walks through a door.  A humanoid walks through the door. Backround   Combining Game Effects (p. 252). This is a new subsection at the end of the “Combat” section: Different game features can affect a target at the same time. But when two or more game features have the same name, only the effects of one of them—the most potent one—apply while the durations of the effects overlap. For example, if a target is ignited by a fire elemental’s Fire Form trait, the ongoing fire damage doesn’t increase if the burning target is subjected to that trait again. Game features include spells, class features, feats, racial traits, monster abilities, and magic items. See the related rule in the “Combining Magical Effects” section of chapter 10 in the Player’s Handbook.  Question Does the humanoid take damage from both fireballs? or does the humanoid only take damage from the "most potent" fireball?


Integer object leading zero changing the value

My apologies in advance as I assume this has already been answered, but I can't seem to find it anywhere.  I'm passing an Integer with a leading zero to a method and instead of resolving as the value passed like I expect (leading zero not an effect) the value is changing.  Here is my call and method:  assertEquals("1800", job.validateTime(1800, 0400));   I test the output:  public String validateTime(Integer startTime, Integer endTime) {         System.out.println(endTime); }   ...and the output is 256 where I would expect it to be 400 or 0400.  Would someone please help me understand what is happening here?  Thank you in advance!


My toddlers like to have ice-cream, candy, sweet, and high sugar cookies. I just worried it could lead to sugar addiction. What are persuasive techniques to reduce sugar intake?


Is it possible to copy to clipboard using Javascript?

I'm working on a sharepoint webpart which has a button pull elements from different text boxes on the same page and collates them together in a single string to then copy to the user's clipboard so they can quickly put together a communication for an issue.  So far I have the below code, but it's not actually copying anything.  I've run it through JSHint and that's not turned up any issues, but I picked up the code at the bottom of the function for copying the text from a tutorial about interacting with the clipboard API for how to copy from a text box, hence why I add everything to the smsToSend text area.  A note for people is that if there's an issue that's brand new and hasn't been sent out before, then the incident update is always 'we are investigating the issue' as this is automatically placed into the field, which is why I testing against it, as both new and update communications would have 'Open' as the incident status.  function generateSMS(){  var issueTitle = document.getElementById("incidentTitle");  var advisorImpact = document.getElementById("advisorImpact");  var incidentUpdate = document.getElementById("incidentUpdate");  var incidentStatus = document.getElementById("incidentState");  var startTime = document.getElementById("startTime");  var endTime = document.getElementById("endTime");  var smsToSend = document.createElement('textarea');  var incidentPriority = document.getElementById("incidentPriority");  var incidentBrand = "TechTeams";  var systemImpacted = document.getElementById("systemImpacted");  var incidentReference = document.getElementById("incidentReference");   if (incidentStatus != "Closed"){      if (incidentUpdate == "We are investigating this issue"){          smsToSend = "P" + incidentPriority + " " + incidentBrand + "IT ISSUE: " + systemImpacted + ": " + issueTitle + ". " + advisorImpact + ": " + incidentReference;      }      else {          smsToSend = "P" + incidentPriority + " " + incidentBrand + "IT UPDATE: " + systemImpacted + ": " + incidentUpdate + ": " + incidentReference;      }  }  else{      smsToSend = "P" + incidentPriority + " " + incidentBrand + "IT RESOLVED: " + systemImpacted + ": " + incidentUpdate + ": Start: " + startTime + " End: " + endTime + " Reference: " + incidentReference;  }   smsToSend.setAttribute('readonly','');   smsToSend.style = {position: 'absolute', left: '-9999px'};   document.body.appendChild(smsToSend);   smsToSend.select();   document.execCommand('copy');   document.body.removeChild(smsToSend); }


Python:embedded for loops: numbering list output

Thank you for clicking. Trying to print a numbered list. Have a for loop for printing list. Ie.  print("COMPOUND:EMBED=okay but not right") # for num in range(1,6+1): #   for error in errors_list: #       num=str(num) #       print(num + ".", error, end=", ") # print()   My wanted output is say:   list_item_1 list_item_2 three,..   Given an exact number of 6 elements, the output is instead:  1. list_item_1 1. list_item_2 1. three,.. 2. list_item_1 2. list_item_2 2. three,.. 3. list_item_1,..list_item_1   Individually, the print is okay. Ie. for item and for range. I've tried embedding the opposite way, list[i] and compounding the two for statements with and. The last of which retrieves: "num is not defined"?


Prove that$ f\Bigg(\sum_{i=1}^n \lambda_i x_i\Bigg) \leq \sum_{i=1}^n \lambda_i f(x_i) $ for a convex function "f"

Let f be a convex function defined on a set I. If $x_1, x_2, ...,x_n \in I$, and $\lambda_1, \lambda_2 ,...,\lambda_n \in [0,1]$ with $\sum_{i=1}^n \lambda_i=1$ then prove that  $$ f\Bigg(\sum_{i=1}^n \lambda_i x_i\Bigg) \leq \sum_{i=1}^n \lambda_i f(x_i) $$   I have no idea where to start, except to use the definition of a convex function: $$ f(\lambda x+(1-\lambda)y) \leq \lambda f(x) + (1-\lambda)f(y) $$  Anyone any ideas of how to approach this problem?


Say $R$ is a commutative ring. Does there exists a subring of $R[x]$ that is isomorphic to $R$?  My approach would be to define the subring of $R[x]$ that generates $R$. Any thoughts?


What does this checkmark icon next to Roblox usernames mean?

I saw someone with this checkmark (✔) symbol next to their username and I am curious about what it means.


A step in the proof of Characterization of $W^{1,\infty}$

In the book of PDE, evans, the proof of the characterization of $W^{1,\infty}$ uses the following argument:  Suppose $u$ has compact support and Lipchitz continuous. Then  $$ \Vert D_i^{-h}u\Vert_{L^\infty(\mathbb{R}^n)}\leq Lip(u), $$ where $D_i^{-h}u$ the difference quotient defined by  $$ D_i^hu=\frac{u(x+he_i)-u(x)}{h}. $$ Then there exists a function $v_i\in L^\infty(\mathbb{R}^n)$ and a subsequence $h_k\rightarrow0$ such that  $$ D_i^{-h_k}u\rightharpoonup v_i \quad\text{weakly in }L^2_{loc}(\mathbb{R}^n). $$  Question: I don't know why such a subsequence exists. Since $u$ has some compact support $\Omega$, then $u\in L^2(\Omega)$. Then there exists a function $v_i\in L^2(\Omega)$ such that  $$ D_i^{-h_k}u\rightharpoonup v_i \quad\text{weakly in }L^2(\Omega). $$ But I don't know why this $v_i\in L^\infty$.


Do all programs running in a computer show up in the processes tab in Task Manager?

The reason I am asking this is because I am curious if there can exist a virus in the computer without me ever being able to know it exists. To be more specific, a virus that emits no signs of any sort.


In the Stack Exchange Android app, where can I see the description, scope and guidelines for each Stack Exchange site?

I posted on  and someone suggested I post on  instead. I wanted to look up the scope and guidelines for each of the two sites, but in the Android app I could not find them.


I see an increased quantity of "are you a bot" captcha.  What can I do to reduce the quantity of these?  I use Google Chrome on iOS. I have "save bandwidth" turned off. (This feature uses a caching compressing proxy at Google). I connect using 3G over giffgaff uk (which uses the o2 network).  I have an account with over 4k rep on the  site. I visit every day, I vote frequently but not anything unusual.