I am trying to start supervisor service supervisor start, as root, but it gives me     env: /etc/init.d/supervisor: No such file or directory    Yet, I can clearly see that file exists:     [root@master vagrant]# ls -l /etc/init.d/                    total 256      -rwxr-xr-x. 1 root root  2062 Oct 17  2014 atd   -rwxr-xr-x. 1 root root  3378 Jun 22  2012 auditd   -rwxr-xr-x. 1 root root  2826 Nov 23  2013 crond   -rw-r--r--. 1 root root 18586 Oct 10  2013 functions   -rwxr-xr-x. 1 root root  5866 Oct 10  2013 halt   -rwxr-xr-x. 1 root root 10804 Nov 23  2013 ip6tables   -rwxr-xr-x. 1 root root 10688 Nov 23  2013 iptables   -rwxr-xr-x. 1 root root   652 Oct 10  2013 killall   -r-xr-xr-x. 1 root root  2134 Nov 23  2013 lvm2-lvmetad   -r-xr-xr-x. 1 root root  2665 Nov 23  2013 lvm2-monitor   -rwxr-xr-x. 1 root root  2989 Oct 10  2013 netconsole   -rwxr-xr-x. 1 root root  5428 Oct 10  2013 netfs   -rwxr-xr-x. 1 root root  6334 Oct 10  2013 network   -rwxr-xr-x. 1 root root  6364 Nov 22  2013 nfs   -rwxr-xr-x. 1 root root  3526 Nov 22  2013 nfslock   -rwxr-xr-x. 1 root root  3852 Dec  3  2011 postfix   -rwxr-xr-x. 1 root root  5383 Mar 30 08:29 postgresql   -rwxr-xr-x. 1 root root  1513 Sep 17  2013 rdisc   -rwxr-xr-x. 1 root root  1822 Nov 22  2013 restorecond   -rwxr-xr-x. 1 root root  2073 Feb 22  2013 rpcbind   -rwxr-xr-x. 1 root root  2518 Nov 22  2013 rpcgssd   -rwxr-xr-x. 1 root root  2305 Nov 22  2013 rpcidmapd   -rwxr-xr-x. 1 root root  2464 Nov 22  2013 rpcsvcgssd   -rwxr-xr-x. 1 root root  2011 Aug 15  2013 rsyslog   -rwxr-xr-x. 1 root root  3085 May 11 21:07 salt-master   -rwxr-xr-x. 1 root root  3332 May 11 21:07 salt-minion   -rwxr-xr-x. 1 root root  1698 Nov 22  2013 sandbox   -rwxr-xr-x. 1 root root  2056 Feb 27 15:57 saslauthd   -rwxr-xr-x. 1 root root   647 Oct 10  2013 single   -rwxr-xr-x. 1 root root  4534 Nov 22  2013 sshd   -rwxr-xr-x. 1 root root  1345 Jun 11 10:20 supervisor   -rwxr-xr-x. 1 root root  2294 Nov 22  2013 udev-post   -rwxr-xr-x. 1 root root 15634 Mar  7  2014 vboxadd   -rwxr-xr-x. 1 root root  5378 Mar  7  2014 vboxadd-service   -rwxr-xr-x. 1 root root 20887 Mar  7  2014 vboxadd-x11   And it contains some script, as expected.  What am I doing wrong?

I've created a bash script but when I try to execute it, I get   #!/bin/bash no such file or directory   I need to run the command: bash script.sh for it to work.  How can I fix this?


I have ubuntu 14.04 lts and it's always freezes.When I wrote this message they froze 5 times.I have notebook with intel core i3,8gb ram and nvidia 740m.How to prevent it?

All operating systems freeze sometimes, and Ubuntu is no exception. What should I do to regain control when...   just one program stops responding? nothing at all responds to mouse clicks or key presses? the mouse stops moving entirely? I have an    In what order should I try various solutions before deciding to pull the power plug?  What should I do when starting up Ubuntu fails?  Is there a diagnostic procedure I can follow?


with no answers.  But still the text of the bounty message says     This question had a bounty worth +50 reputation from juergen d that ended yesterday; you must award this bounty as soon as possible   Please remove the highlighted text if the question has no answers. I can't award it.

The bounty I offered on  is now in its grace period and the information box tells me:     you must award this bounty as soon as possible   But there are no answers - what do I do?


I am writing a C++ code. here The goal of the program is to create single buffer from two or three different buffers. Here is the code I wrote.  #include <iostream> #include <cstdint> #include <cstring>  int main() {     uint8_t LLDP_STANDARD_DST_MAC_STRING [] = {0x01,0x80,0xc2,0x00,0x00,0x0e};     uint16_t LLDP_EtherType={ 0x88CC};`     uint8_t* buf=new uint8_t[14];`     uint8_t LLDP_STANDARD_SRC_MAC_STRING[] = {0x11,0x81,0xC3,0x01,0x01,0x1e};`     memcpy(buf,&LLDP_STANDARD_DST_MAC_STRING,6);     memcpy(buf+sizeof(LLDP_STANDARD_DST_MAC_STRING),&LLDP_STANDARD_SRC_MAC_STRING,6);      std::cout << "first data " << sizeof(buf) << std::endl;     std::cout << "firt data " << (uint8_t) buf[12] << std::endl; }   When I run the code, size of buf  the code is priting 8. It is wrong? The value is not clear text. some different charatcter.   Thanks for your help.  Best regards Sothy

First off, here is some code:  int main()  {     int days[] = {1,2,3,4,5};     int *ptr = days;     printf("%u\n", sizeof(days));     printf("%u\n", sizeof(ptr));      return 0; }   Is there a way to find out the size of the array that ptr is pointing to (instead of just giving its size, which is four bytes on a 32-bit system)?


I was watching a video, and they showed that they were establishing a float array like this:  private final float x[];   I have always done this:  private final float[] x;   I tested both and neither produces an error.  Is there a difference or is this just preference?

I have recently been thinking about the difference between the two ways of defining an array:   int[] array int array[]   Is there a difference?


I'm using a method getTableContent that fetch some values from the db and returns as String array. The methods goes as follows,   public static String[][] getTableContent(Connection con){      ResultSet rs = null;     Statement st = null;             String [][] data = null;      String sql = "select COF_NAME, SUP_ID, PRICE, SALES, TOTAL from COFFEES";      try {          st = myConn.createStatement();         rs =  st.executeQuery(sql);          if(rs.last()){              data = new String[rs.getRow()][5];             rs.beforeFirst();         }          int count =0;          while ( rs != null && rs.next() ){              data[count][0] =rs.getString(1);             data[count][1] =rs.getString(2);             data[count][2] =rs.getString(3);             data[count][3] =rs.getString(4);             data[count][4] =rs.getString(5);           }     }       catch (SQLException e) {          e.printStackTrace();     }      return data;         }   I get the table values in another array and trying to print as following,   String [][] myData =  getTableContent(conn);      for ( int i =0; i < myData.length; i++ ){          for (  int j =0; j < myData.length; j++ ){              System.out.print( (myData[j]) + " ");         }          System.out.println();     }   All I'm getting some machine values provided below as sample ,      [Ljava.lang.String;@314e4baf [Ljava.lang.String;@4cb71983    I used myData[j]).toString() but that doesn't help me. How can I improve the code ? There are no error in the program.

In Java, arrays don't override toString(), so if you try to print one directly, you get the className + '@' + the hex of the  of the array, as defined by Object.toString():  int[] intArray = new int[] {1, 2, 3, 4, 5}; System.out.println(intArray);     // prints something like '[I@3343c8b3'   But usually, we'd actually want something more like [1, 2, 3, 4, 5]. What's the simplest way of doing that? Here are some example inputs and outputs:  // Array of primitives: int[] intArray = new int[] {1, 2, 3, 4, 5}; //output: [1, 2, 3, 4, 5]  // Array of object references: String[] strArray = new String[] {"John", "Mary", "Bob"}; //output: [John, Mary, Bob]


I would like to alternate row colors in a tabular environment. I found colortbl useful. To simplify writing, I built the following macros to alternate row colors (see MWE below). However, I cannot understand why the \crc macro cannot coexist with a \multicolumn, whereas \rca or \rcb work like a charm.  And, more important, how can I simplify writing such as I always use the same macro name to alternate colors, even when I'm using \multicolumn?  \documentclass {article}      \usepackage {colortbl}  \begin {document}  % define row colors A and B \def\rca{\rowcolor [rgb] {0.90, 0.95, 1.0}} \def\rcb{\rowcolor [rgb] {0.80, 0.90, 1.0}}  % This one works like a charm \begin {tabular} {|l|l|} \hline     \rca \multicolumn {1} {|c|} {one} & 1 \\ \hline     \rcb two & 2 \\ \hline     \rca three & 3 \\ \hline \end {tabular}  % use current row color and set color for next row \def\cseta{\gdef\crc{\rca\csetb}} \def\csetb{\gdef\crc{\rcb\cseta}} \cseta          % (re)set \crc to the row color A  % This one does not want to compile! % ! Misplaced \omit. % \multispan ->\omit %                   \@multispan % l.23     \crc \multicolumn {1} {|c} {one} %                                          & 1 \\ \hline \begin {tabular} {|l|l|} \hline     \crc \multicolumn {1} {|c} {one} & 1 \\ \hline     \crc two & 2 \\ \hline     \crc three & 3 \\ \hline \end {tabular}  \end {document}

I want to use row coloring with \multicolumn. The MWE below works, but if I change  to the commented, colored line, I receive a "misplaced \noalign". What do I wrong?  \documentclass{article} \usepackage{booktabs,colortbl,xcolor} \begin{document}  \begin{tabular}{p{1.7cm}p{1.3cm}p{1.3cm}p{1.35cm}p{1.35cm}p{1.35cm}p{1.35cm}p{1.7cm}} % \toprule % \multicolumn{1}{>{\rowcolor{lightgray}}c}{}  &\multicolumn{7}{>{\rowcolor{lightgray}}c}{String length}\\  \multicolumn{1}{c}{}  &\multicolumn{7}{c}{String length}\\ \rowcolor{lightgray} Function & 16,384 & 32,768& 65,536 & 130,072 & 262,144 & 524,288& 1,048,576\\ \midrule lower1  & 0.19 & 0.77 & 3.08 & 12.24 & 49.39 & 198.42 & 791.22\\ lower2& 0.0000 &  0.0000 & 0.0001 & 0.0002 & 0.0004 & 0.0008 & 0.0015\\ \bottomrule \end{tabular}  \end{document}   I was experimenting with a solution like this, because I receive strange table heading, like below. The code you suggested works fine in MWE, but in my real text, with copy&paste from the answer, it produces the strange heading. Any idea, what can change the behavior?


Let Y denotes the subspace $[-1,0)\cup(0,1]$ of real line $\mathbb{R}$. How the each set $[-1,0)$ ,  $(0,1]$ are open in Y . The definition of Open Set is that it must not contain its boundaries. the author (Munkres) says that the Sets $[-1,0)$ ,  $(0,1]$  are open in Y but not in $\mathbb{R}$.The question may sound easy but please try to explain. thanks !. what i think is that if i take a point $-1$ and  make a open ball of radius $\epsilon$ then it will cross the boundary $-1$ hence the set can't be open.

Let $X=\mathbb{R}$ and $S=[-1,1]$, i don't quite understand why $[-1,0)$ is open in $S$ but not open in $X$. As far as i know, to show a set is open, we need to show there exist an open ball $B(x,r), r> 0$ st for all $x\in [-1,0)$ ,$x\in B\subset S$, however, i still can't see why  $[-1,0)$ is open in $S$ but not open in $X$. When we look at -1, i don't think this is a interior point of S.


The image below shows option chains in thinkorswim. Note the percentages on the right hand side:  The percentage on the right hand side is the overall volatility for options in each expiration (while the number in parenthesis is the expected move based on the volatility) (). I can't seem to figure out how they're determining the volatility. It's not available in the API. Is this some sort of average of all the underlying strikes?

By searching online, I have found three methods to compute the expected move of a stock based on option prices and implied volatilities: Method 1: Extract the price of a Straddle ATM of the front month  --> Exp_Move = (call ATM + put ATM) Method 2: Take the price of a Straddle ATM of the front month and multiply it by 0.85  --> Exp_Move = (call ATM + put ATM)*0.85 Method 3: Compute the expected move by scaling the implied volatility of the nearest expiration  --> Exp_Move = Stock_Price * IV/100 * SQRT(n/365) DOUBT NO. 1: Which one is the most accurate one between method 1 and method 2? Where does the "0.85" come from? DOUBT NO. 2: To compute the Exp_Move with Method 3 I need the IV... I still do not understand how I can compute the IVx of the front month expiration based on the implied volatility of the options with that expiration. Is that a sort of weighted average of the implied volatilities? I noticed on tastyworks's website this description:  Implied Volatility (IVx): The implied volatility (IVx) metric displayed in the option chain is calculated using the VIX-style calculation described at the following link.  However, this seems something almost impossible to reproduce based on historical option data provided by OptionMetrics. Is there a way to reach very accurate estimation of the IVx based on the implied volatilities or the prices of the options of that precise expiration? I attach a couple of pictures of the same option chain where I explain what I am trying to compute... (By the way... I have no idea why two different brokers platforms provide slightly different IVx values...). Image 1 - Option chain on tastyworks IVx:  Image 2 - Option chain on thinkorswim IVx:


I'd like to install rasmover.py which I've been able to find in github  ... I'm working with rasters that cannot be georeferenced precisely ... rasmover may allow me to adjust rasters to a best fit ... any advice on how to install plugins not listed in plugin manager?

Due to various IT policies at my workplace, QGIS is installed on a machine that is not connected to the internet. I wish to install a couple of QGIS plugins on this system.  I have downloaded the required plugins from . How do I install them in QGIS?


Yeah, simple as that.  Why do most of the people use a plane which emits light (in most cases) and not a lamp? What's the difference between them? When do I use a lamp and when the emission node?  Thanks in advance.

Both an area light and an emissive polygon can be used to create lights. What is the difference between the two?


In my program, I create an attraction and fill out the number of ticket types, is title and cost, and then I exit the program and run it again.  I have a constructor that reads elements from a file. When I then try to read an array element, it gives me a NullPointerException error even though the element is not null.  When I comment out the code block below where the error is located, I get a NumberFormatException error instead for the input string, "Tour Only", so I know it's not null.  fileScanner.nextLine(); for (int i = 0; i < getTicketTypesNum(); i++)     this.ticketTypeTitle[i] = fileScanner.nextLine(); fileScanner.nextLine();   The code in full is below.  Attraction.java  // The constructor. public Attraction(Scanner fileScanner) {   ...    // The data read before the error.   fileScanner.nextLine();   this.ticketTypesNum = Integer.parseInt(fileScanner.nextLine());   fileScanner.nextLine();    fileScanner.nextLine();   for (int i = 0; i < getTicketTypesNum(); i++) {     // Line where the error is located.     this.ticketTypeTitle[i] = fileScanner.nextLine();   }    fileScanner.nextLine();   for (int i = 0; i < getTicketTypesNum(); i++)      this.ticketTypeCost[i] = Integer.parseInt(fileScanner.nextLine());   fileScanner.nextLine();    ... }   // Store the attraction information and write it to file. public void writeData(PrintWriter pw) {   ...    pw.println("Number of Ticket Types:");   pw.println(getTicketTypesNum());   pw.println();    pw.println("Ticket Titles:");   for (int i = 0; i < getTicketTypesNum(); i++)     pw.println(getTicketTypeTitle()[i]);   pw.println();    pw.println("Ticket Costs:");   for (int i = 0; i < getTicketTypesNum(); i++)     pw.println(getTicketTypeCost()[i]);   pw.println();    ... }   If you need more code, I'll edit my question to include more.  Thank you for your help!  UPDATE  I tried commenting out the line where I had the error out and continued running the code, and I get a NullPointerException whenver I have to read an array element.

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


I had run apt upgrade a couple of days back, and restarted my PC a while after, when the top bar and the launcher disappeared. I have tried all the following solutions, but none of them worked:     and reinstalled it again.   Running unity --reset or initctl restart unity-panel-service just flashes the top bar and the launcher and disappears again.  Removing the .compiz folder   EDIT:      I have been searching for solutions for days now without any luck. Although the above solutions have been working for others, none of them seem to work for me. How do I fix this?  Currently running Ubuntu 16.04.3 LTS.

When I login, nothing happens.   I am presented with my desktop wallpaper.    No Dash, no Launcher, nothing.


The limit the following sequence is $\frac{1}{p+1}$. I have tried to prove it, but I don't success. Could you help me?  $$x_n=\frac{1^p+2^p+...+n^p}{n^{p+1}}$$  $$p\in\mathbb{N}$$  Thanks in advance!

What is the result of the next limit:   $$ \lim_{n \to \infty} \frac{ \sum^n_{i=1} i^k}{n^{k+1}},\ k \in \mathbb{R} $$  Why (theorem)?


I've just looked through every printed book I've bought over the past year and noticed a curious pattern that I'd never given much thought until now (due to currently preparing a manuscript for publication).  Why is it that some books (maybe all books?) don't indent the first paragraph directly after a chapter or subsection title but then proceed to indent all others?  Is this the standard approach? Has it always been this way, and I've simply not noticed such a minor detail? And should I mimic this?

A colleague explained to me that it is a typographical rule to not set an indent for the first line of the very first paragraph of a text, the one that starts right after the headline. Instead, the indentation should start with the second paragraph. However, I am finding examples in various publications where the indentation starts right with the first paragraph. Then again, others do it the way it was told me.  Is there a "right" way to do it, and if so, why? If not, what are the advantages/disadvantages of either method?


I noted today that I got -15 points on an .    Going to that answer, I however cannot see where the negative score came from:    How were these -15 points computed?

On Stack Exchange, users may gain a certain level of reputation.  What does reputation do? How can a user gain or lose reputation?   See also   in the Help Center  - Maximum amount of votes a user can use in a day and reputation requirements to vote.  - How to get an exact overview of the actions that got you your reputation.  - A full list of all privileges granted at each reputation level on all sites.


I have installed Ubuntu 13.04 but Wobbly effect is not there.. I need that effect.. I searched CCSM but the option to enable is not there. Help.

I've recently set up the compiz cube again, and I was very happy to find that that flickering window glitch is gone! However, the cube reflection and deformation plugins are also gone.  I am running a fresh 12.10 install, and I have every compiz plugin package installed (including compiz-plugins-extra, which supposedly contains everything that compiz-fusion-plugins-extra package used to have), but those two plugins are still missing. I haven't been able to find anyone with the same problem.   Any ideas? (thanks!)


I have a vector of Moves, and a vector of scores. I would like to sort the vector of moves (based on the other vector), without creating an intermediate container. (and preferable without writing my own sort, there are already so many good). The reason I don't want an intermediate is performance reason, this portion is currently the primary bottleneck. Do someone know a neat fast hack that accomplish this? Note: making score part of Move wasn't a good idea, Move grew to much and I got loads of cache-misses that way. Also, most move-vectors wont need sorting.  struct Move { unsigned char f,t,p,m; }; std::vector<Move> mvlst; std::vector<int> scores;   Sort mvlst based on scores  Update: I found , It seams to work.

I have several std::vector, all of the same length. I want to sort one of these vectors, and apply the same transformation to all of the other vectors.  Is there a neat way of doing this? (preferably using the STL or Boost)?  Some of the vectors hold ints and some of them std::strings.  Pseudo code:  std::vector<int> Index = { 3, 1, 2 }; std::vector<std::string> Values = { "Third", "First", "Second" };  Transformation = sort(Index); Index is now { 1, 2, 3};  ... magic happens as Transformation is applied to Values ... Values are now { "First", "Second", "Third" };


Since I have upgraded my system from Ubuntu 18.04 to 18.04.1, I am facing a weird problem.  I am unable to open any directory placed on the desktop by double-clicking on it. However, when I Right-Click on the folder icon and select Nautilus it opens up. I can even access them by opening Nautilus from the menu. I don't know why is this happening. Is this some bug of 18.04.1? Should I revert back to 18.04?.  Update  I tried following things which didn't worked   Tried reinstalling gnome-shell  sudo apt-get install --reinstall gnome-shell  Tried reinstalling nautilus  sudo apt-get purge nautilus sudo apt-get install nautilus  Checked the permission of folders in desktop, they are ok Checked mouse setting in the Settings menu, they are ok   I also tried installing Ubuntu 18.04.1 in a virtual box with same iso file, what I found is that in VM newly installed Ubuntu works fine I can open the folder by double-clicking on them. Hence I believe I might have installed some drivers along the way which are creating a problem.

When I try to open folders (and the trash can) by double-clicking on them on the desktop nothing happens. However, when I right-click on the folder, select "Open with another application", and then select Nautilus it opens normally. I think that it has something to do with the default file manager maybe? (I can open other files that aren't folders normally)


I would like to know whether someone could tell me   1) some of the online programs that will predict the top microRNAs that bind to 3`UTR of a specific gene (for eg-GAPDH).   I am relatively new to the field.  thanks

I am trying to find miRNAs that bind to the 3'UTR of a specific gene. What is the best way of doing that (that is, with a good scoring analysis that is most commonly used by researchers in this area)? I would also like to know the other possible methods if there are multiple ways of doing this.


I was having issues with pulseaudio and had to every time type in 'pulseaudio -D' in terminal each time I booted up. However, this was quite frustrating and so I was looking forward to make pulseaudio to startup each time at bootup by editing .bashrc  I added these lines at the end of the .bashrc file :  until [[ `ps aux | grep "pulseaudio -D" | grep -v grep | wc -l` -eq 1 ]] do     pulseaudio -D >/dev/null 2>&1     if [[ `ps aux | grep "pulseaudio -D" | grep -v grep | wc -l` -gt 1 ]]     then         kill -9 `pidof pulseaudio`         pulseaudio -D     fi     But since after that I have been getting the error of 'unexpected end of file' as enclosed in the .   How can I solve it?

How can I run scripts automatically when Ubuntu starts up so I don't have to run them manually after startup?


I've been active in SO for about 3 months and i was wondering why sometimes SO show those top 5% this month and others top 2% this quarter.      My questions are:   How SO decide to show monthly, quarterly, etc. Which one is better to show? (if there is any) Are this rank links showed to every user with enough rep? If so, how much rep is "enough"?

I always wondered on what algorihm the best league of mine is chosen.    I am in the 0.16% of this quarter. That is rank 171 this quarter. But I am also ranked 113th this month.  Why is the stat for the quarter displayed when I have a better ranking in the month?


What is the difference between CURRENT_TIMESTAMP and GETDATE() in SQL Server?  SELECT CURRENT_TIMESTAMP, GETDATE()

Using SQL Server - which is the fastest or best practice method to use for date retrieval? Is there a difference?


I would like to have optional variables in my script, because I don't always need to use them. For example in my script I have: hiveParams="" if [ "$1" == hiveParams=* ]; ### if the first param starts with hiveParams= then echo "$hiveParams" spark submit --conf spark.sql.hive.conf.list=\$hiveParams fi  And when I run the script I would like that the script takes "TestHiveParams" and replace it in $hiveParams sh test.sh hiveParams="TestHiveParams"  How can I make this run? Update: I have added:  set -o --  and run the job: sh test.sh --hiveParams="someParams"  and I get that the numbers of parameters is 0. How should I define it , so that it recognizes it?

Say, I have a script that gets called with this line: ./myscript -vfd ./foo/bar/someFile -o /fizz/someOtherFile  or this one: ./myscript -v -f -d -o /fizz/someOtherFile ./foo/bar/someFile   What's the accepted way of parsing this such that in each case (or some combination of the two) $v, $f, and  $d will all be set to true and $outFile will be equal to /fizz/someOtherFile?


I am trying to RDP into a machine, but it has exceeded its maximum number of users. How do I go about kicking one of them (assuming I have admin rights).

We use Windows "Remote Desktop" to log into server machines. At the moment, I am getting the following error message:  The terminal server has exceeded the maximum number of allowed connections.   Now, the cause is obvious (2 other people are logged on right now!). I recall that in the past I solved this by logging on to some other machine in the same domain and then going to some admin tool which I cannot recall. From there I could see who was logged in and remotely terminate their session (assuming I had sufficient privileges) -- thereby freeing up one of the connections.  Does anyone know how to do this?


Im reading Set theory of Jech and its said that     Let $X,Y$ sets, then $X\times Y:=\{(x,y):x\in X\land y\in Y\}$. Then $X\times Y$ is a set because $X\times Y\subseteq\wp(\wp(X\cup Y))$.   Note: here $\wp$ means "power set". It is also assumed that $(x,y):=\{\{x\},\{x,y\}\}$.  Im not sure why if something is contained in a set then it is also a set, I assume that it is because there exists a formula such that $X\times Y$ could be defined by the axiom schema of separation. Im right, or there is other reasons to say that $X\times Y$ is a set?

In ZFC set theory, every element object is a set. We know or feel that if $X$ and $Y$ are sets, their cartesian product $X\times Y$ is a set.  My question is: Why if $X$ and $Y$ are sets, their cartesian product $X\times Y$ is a set?


It seems that the commands \xrightarrow, etc. in mathtools package don't allow me to put text above or below two arrows (\rightrightarrows). Is there any way to do this with extensible arrows? A crude way would be  \overset{b}{\underset{a}{\rightrightarrows}}   but the arrows are not extensible. For that matter, it also doesn't support \twoheadrightarrow, etc.


Once one is within the Schengen union.  Is it necessary to have one's passport crossing from one Schengen country into another? For example, a Paris tour bus provides a Brussels guided tour for the day.

My current situation is that I have residence permit of Germany (as a stamp in passport) and I wish to apply for UK visa in next few days from Germany and won't have my passport anymore during the processing time.  Instead of waiting for the process, I wish to travel to Scandinavian countries immediately on holidays, later receive my passport from visa center after I return back to Germany.   I am wondering if photocopy of passport and residence permit suffice as identity proof to border control (if I face them)? What else are valid documents that I can show as valid identity proof to border control? What are the exact problems I will face if I face the border control, and they are not satisfied with my travel documents?


I had windows 7 installed before I install ubuntu, I downloaded ubuntu when I had windows and installed it but I removed all my data by accident and I lost my windows 7, now I'm trying to install windows back but I completely fail doing that!   Why do you fail?  Actually I downloaded windows ISO file, I searched online how to install windows using ubuntu and I knew that I have to formate my USB  to NFTS using gparted, I did, everything is fine now I opened UneBootIN but I can't find my USB, can't be detected then error message pop-up saying I have to formate my USB to FAT32, and I know that I can't do that to install windows 7 or boot it, but I gave it try and formatted my USB to FAT32, everything went well and it made the usb boot-able I restarted my device and pressed F2, it showed my USB, I choosed it and pressed enter, it said in the top: UnEbootIN and there's something in the list called 'Default' and message down saying 'Boot or whatever will happen, install or boot after 10 seconds, I wait 10 seconds and it recount again, I press enter and nothing happen just re count the 10 seconds! and I can't find any similar programs like UneBootIN to do that for me so i'm stuck on ubuntu only, I wanna install ubuntu as alternate os when I install windows but I'm just stuck on it now..  I wanna something to make me make windows 7 bootable instead of UneBootin because it doesn't detect NTFS Formatted USB, and I can't go with FAT32 cuz it doesn't work!

I'd like to create a Windows bootable USB stick, but I don't have a Windows machine with me at the moment to do so. How could I achieve the same using Ubuntu?


The question  is :  Let be $X$ a separable normed vectorial space and $S$ a subspace de $X$ $ \varphi : S \rightarrow \mathbb{F}$. Show without use Hahn- banach' Theorem (and zorn's lemma) that exists an extension $f$ of $\varphi$ with $\|\varphi\| = \|f\|$.  I have no idea how I start. I only know that $X$ has a subset dense and countable. I think to extend $\varphi$ for the S ' s Closure, but I don't know if "S" is the subset dense in$ X$.

I was reading about the Hahn-Banach Theorem, its many versions and their proofs. It's known that in the proofs we need Zorn's Lemma. But in the book that I'm reading, the author said if $X$ is a separable space then it's possible to prove the Hahn-Banach Theorem without the Zorn's Lemma.  How can we show there is a suitable extension of a linear functional without Zorn's lemma?


How can I remove the title of my list of figures? I am able to do it for the table of contents but not for the list of tables or figures.

I'd like to modify the names used to typeset some of my document elements. For example, the caption of figure floats should change from "Figure" to "Fig.", and my \tableofcontents sectioning heading shouldn't read "Contents", but "Table of Contents". How can I do that?  \documentclass{article} % \usepackage[english]{babel} \begin{document} \tableofcontents \section{foo} \begin{figure}[h] \centering \rule{1cm}{1cm}% placeholder for graphic \caption{A figure} \end{figure} \end{document}


Suppose we have n jointly distributed random variables $x_i,i=1,...,n,$ with mean and variance $E(x_i)=\mu_i$, $Var(x_i)=\sigma^2_i$ and covariance $Cov(x_i,x_j)=\sigma_{ij}.$ Then the weighted sum of the n random variable has mean  $E\bigg(\displaystyle\sum_{i=1}^n\omega_ix_i\bigg)=\displaystyle\sum_{i=1}^n \omega_i\mu_i$  and variance  $Var\bigg(\displaystyle\sum_{i=1}^n\omega_ix_i\bigg)=\displaystyle\sum_{i=1}^n\displaystyle\sum_{i=1}^n\omega_i\omega_j\sigma_{ij}$  How to prove both these formulas?  Any member may show its correct proof along with examples.

I understand the proof that  $$Var(aX+bY) = a^2Var(X) +b^2Var(Y) + 2abCov(X,Y), $$  but I don't understand how to prove the generalization to arbitrary linear combinations.  Let $a_i$ be scalars for $i\in {1,\dots ,n}$ so we have a vector $\underline a$, and $\underline X = X_i,\dots ,X_n$ be a vector of correlated random variables. Then $$ Var(a_1X_1 + \dots a_nX_n) = \sum_{i=1}^n a_i^2 \sigma_i^2 + 2 \sum_{i=1}^n \sum_{j>i}^n a_i a_j \text{ Cov}(X_i,X_j)$$  How do we prove this? I imagine there are proofs in the summation notation and in vector notation?


I have an array of type double storing 3 values I want to increment the value by 3 cents but I get a bunch of decimal places I can't seem to figure out what the problem is   double [] cupsPrice = {0.93, 1.65, 2.77};     for(int i=0; i<7; i++){     for(int l=0; l<3; l++){         cupsPrice[l] += 0.03;     } }////expecting 0.96 in second run but is returning 0.0960000000000001


How to edit .pdf files in Kubuntu 13.04 ? Is there any supported software like "Adobe Acrobat" with the help of which I could do editing ?

I typically have two needs:  Scenario A. Change a single PDF page.  In this case I have a PDF but not the original source file used to create the PDF. I don't want to try to recreate the document from scratch. I'd like to open the PDF and change a few things. A good example of this scenario: I was responsible for planning a big event at a campground site, I had a PDF of the site. I wanted to start with that document, highlight some parts, add some labels, remove some parts that weren't relevant.   or   Scenario B. Combine PDFs or extract page(s) from a PDF  This scenario usually arises because I want a single PDF deliverable that is made up of parts that are best created in different programs. In this case I have the source files for all the documents but they don't play well enough together to easily create a single PDF deliverable. For part of it, I may want to use Libre Office Writer. For another page I may want to use Gimp. Still another page I may use Libre Office Calc. I could use Writer as the master document and embed images or the Calc object into that, but for ultimate control, you can't beat separate PDF documents that are then combined.  What are the best tools / processes for editing PDFs in Ubuntu?


So I have a dictionary in python in which I have a number for the key with a value attatched to it.   myDictionary = {"0" :0, "1":0, "2":0, "3":0, "4":0, "5":0, "6":12, "7":0,"8":0,"9":0,"10":0,"11":0, "12":0,"13":12}   I run a doctest that says:  >>> myDictionary = {"0" :0, "1":0, "2":0, "3":0, "4":0, "5":0, "6":12, "7":0,"8":0,"9":0,"10":0,"11":0, "12":0,"13":12} >>> new_Val = 0 >>> method0 = WordClass (new_Val, myDictionary) True   I was doing some debugging ad printed out my dictionary to make sure I was going through the right values in the dictionary. When I printed it out, it looked like this:  {'11': 4, '10': 4, '13': 0, '12': 4, '1': 4, '0': 4, '3': 4, '2': 4, '5': 4, '4': 4, '7': 4, '6': 0, '9': 4, '8': 4}   They are all out of order. Does python do that by default when storing memory or something? If so, is there some documentation somewhere that I can look at?   Thank you

Here is the dictionary I have  propertyList = {     "id":           "int",     "name":         "char(40)",      "team":         "int",     "realOwner":    "int",      "x":            "int",     "y":            "int",      "description":  "char(255)",      "port":         "bool",     "secret":       "bool",     "dead":         "bool",     "nomadic":      "bool",      "population":   "int",     "slaves":       "int", }   But when I print it out with "\n".join(myDict) I get this  name nomadic dead port realOwner secret slaves team y x population id description   I know that a dictionary is unordered but it comes out the same every time and I've no idea why.


I'm using QGIS 2.14 (Mac), but I have had the same problem with 2.8 (Ubuntu). When I am editing a shapefile, QGIS seems to spontaneously corrupt the data in unpredictable and catastrophic ways that include:   Duplication of features Deletion of features Scrambling of attribute data   Most recently, this occurred while using the Table Manager plugin to rename a column of the attribute table. Upon saving the change, one of the columns of the attribute table (not the one being renamed) was suddenly scrambled such that features were unpredictably reclassified, completely corrupting the file and forcing me to reload a backup version.    The problem seems to be associated with saving, though I usually don't discover the corruption until some time after it occurred, so I can't say for sure what the circumstances were in most cases, the exception being the case described above.   I realize this might be the same problem described here    If so, it is evidently still a problem in 2.14, and there was never a satisfactory answer provided. If not, does anyone have a clue as to what is going on? This makes QGIS completely unusable.   -------------- EDIT ---------------  I was able to replicate the result by reloading a backup version and repeating the renaming and saving that precipitated the corruption the first time. The problem seems to be specifically with the Table Manager plugin, similar to what was reported here:   Apparently it remains unresolved, so I guess one should stay away from Table Manager for the time being.

I'm hoping someone out there might be able to help or suggest some tests to try and resolve some very odd QGIS behaviour of late...  Our core GIS team of 4 users has been testing v2.10 prior to roll-out for the remainder of the organization.  In the past couple of weeks we have had some very odd shapefile corruption things happening and are yet to isolate or identify a potential cause...  These have included:   Editing one line (using the scissor tool to split into two records) and having the resulting records attributes completely replaced by attributes from another geometry no-where near the edited row (spatially or in the attribute dbf) Line geometries completely disappear while their attributes get associated with an unrelated geometry  Line geometry get partially deleted and replaced with a vertice in infinity (line visually extends beyond the dataset and no matter how far zoomed out you never see the end)   The above is happening in a polyline layer, that we did discover has some multi-line geometries..? Perhaps this is impacting... but never saw this issue with v2.8 and the same layer. The layer has undergone MANY save-as's in the past week and many verify geometry checks as we thought invalid geometry may have been the cause...  In another separate layer yesterday, to a separate user (me) i created a layer with approx 30 polygons... adding, deleting some and doing some 'avoid intersection' to remove overlaps. Layer looks fine in qgis, saved and also a save-as to a completely new file but when i load into ArcGIS online (and later is ArcMap as a test) some of the overlaps and deleted objects are still there. Close and reopen qgis,  reopen the file and they are definitely not.  The project was created in v2.8 that i was editing in (but had been saved in 2.10).  Does anyone have any ideas/suggestions.  We do still have 2.8 installed as well as 2.10? We have never encountered issues like this when testing other new qgis versions while still running old ones?


I have checked the positions of assembler array in this functions and they are not empty. But I am getting the following error Exception in thread "main" java.lang.NullPointerException  While debugging the .equals method is giving this exception. So please help in understanding this problem.  Here is the code snippet.  public static void lc(int i, String[][] assembler, String[][] mc) {         int x = Integer.parseInt(assembler[0][3]),j;         int flag;         for(j=0;j<13;++j) {             flag = 0;             if(assembler[j][1].equals("START") || assembler[j][1].equals("END") || assembler[j][1].equals("STOP") || assembler[j][1].equals("LTORG") || assembler[j][1].equals("EQU") || assembler[j][1].equals("ORIGIN")) {                 flag = 2;                 //System.out.println("Hi");             }             if(assembler[j][1].equals("ORIGIN")) {                 x = Integer.parseInt(assembler[j][3]);                 mc[j+1][0] = assembler[j][3];                 flag = 1;             }             if(assembler[j][2].equals("DS")) {                 x += Integer.parseInt(assembler[j][3]);                 mc[j+1][0] = Integer.toString(x);                 flag = 1;             }             if (flag == 0) {                 x += 1;                 mc[j + 1][0] = Integer.toString(x);             }             if(flag == 2)                 mc[j+1][0] = Integer.toString(x);         }         mc[j][0] = "null";     }

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


I need if element is visible current viewport alerts something message    .wrapper {   margin: auto;   width: 400px;   height: 300px;   outline: 1px solid red;   overflow-y: scroll; }  .element {   font-family: sans-serif;   width: 100%;   height: 50px;   border-bottom: 1px solid grey; }  .element.active{   background: #ccc; }

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Is there an efficient way to tell if a DOM element (in an HTML document) is currently visible (appears in the viewport)?  (The question refers to Firefox.)


I know that this was not possible as a scenario for SQL Server 2012 -> 2008 but I wonder if MS made any changes here with the 2014 version.  We have SQL Server 2014 version with a fairly large database, We’d like to restore a backup of that database to SQL Server 2008 R2 because that physical machine has more space, RAM,…  I’m getting standard error message when I try to restore backup but I was wondering if there is something else in SQL Server 2014 that I might be missing.  Also, are there any tools like Redgate/SQLSentry that will be of any use while working with databases size of hundreds of GB size?

I'm getting an error whenever I restore a testing database on SQL Server 2005 that was backed up from SQL Server 2008 R2. It seems that I cannot restore from a higher version of sql onto lower version, how can I solve this?     The media family on device is incorrectly formed. SQL server cannot process this media family. RESTORE HEADERONLY is terminating abnormally.   I already tested to restore the same file in its own server (SQL Server 2008 R2) and it works, so it's not corrupted.  I cannot install the updated version of SQL into my older server, so how can I use my older SQL Server 2005 as a dev server but with the updated life data from a different instance?


I am a first year graduate student in biostatistics, and I have somewhat of an idea of the difference between REML and ML. However, I want a more in-depth understanding of each estimation method, especially when it comes to Likelihood ratio tests.   I know that you cannot use REML for likelihood ratio tests, and it has something to do with using the residuals of the means. If you take the residuals of the means, the models are no longer nested (nested models are needed for LRT). However, I really want a more thorough explanation as to why we cannot use REML for LRT's.  I will appreciate it if someone can explain this to me.

I have read in the abstract of  that:     "The maximum likelihood (ML) procedure of Hartley aud Rao is modified by adapting a transformation from Patterson and Thompson which partitions the likelihood render normality into two parts, one being free of the fixed effects. Maximizing this part yields what are called restricted maximum likelihood (REML) estimators."   I also read in the abstract of  that REML:     "takes into account the loss in degrees of freedom resulting from estimating fixed effects."   Sadly I don't have access to the full text of those papers (and probably would not understand if I did).  Also, what are the advantages of REML vs. ML? Under what circumstances may REML be preferred over ML (or vice versa) when fitting a mixed effects model? Please give an explanation suitable for someone with a high-school (or just beyond) mathematics background!


We know that in an inelastic collision that total momentum of the system before collision equals the total momentum after collision. But total kinetic energy before collision is not equal to total kinetic energy after collision.   How is possible given that the formula of momentum is $mv$ and the formula of kinetic energy is $\frac{1}{2} mv^2$; both are dependent on mass and velocity.

In inelastic collisions, kinetic energy changes, so the velocities of the objects also change.  So how is momentum conserved in inelastic collisions?


I opened up a remote I had and saw there were two soft "objects" next to the display in it. What is it's name and function?

The LCD below is from a cheap digital clock which was (obviously) damaged (broken glass).    The electrical connection between the PCB and the display was realized with this pink strip.    Its flexible...    ...and consists of alternating rows of conductive and insulating material between the pink boarders.    [above image was altered in contrast/brightness to highlight the alternating strips]  What is this kind of connector called? Is it only used for displays?   I am pretty impressed that the connection is reliable just from the very slight pressure between the strip and the PCB. Also, its easily removable from the display. There seems to be some conductive layer on the glass, from where the signal goes into the displays internals. This connection seems to be damaged for the three rightmost signals, where the glass is broken.


On Fedora, root is coming up invalid.  WHat is solution?

This is a  about Server Security - Responding to Breach Events (Hacking)   See Also:                  Canonical Version I suspect that one or more of my servers is compromised by a hacker, virus, or other mechanism:   What are my first steps? When I arrive on site should I disconnect the server, preserve "evidence", are there other initial considerations? How do I go about getting services back online? How do I prevent the same thing from happening immediately again? Are there best practices or methodologies for learning from this incident? If I wanted to put a Incident Response Plan together, where would I start? Should this be part of my Disaster Recovery or Business Continuity Planning?   Original Version       2011.01.02 - I'm on my way into work at 9.30 p.m. on a Sunday because our server has been compromised somehow and was resulting in a    attack on our provider. The servers access to the Internet   has been shut down which means over 5-600 of our clients sites are now   down. Now this could be an FTP hack, or some weakness in code   somewhere. I'm not sure till I get there.      How can I track this down quickly? We're in for a whole lot of   litigation if I don't get the server back up ASAP. Any help is   appreciated. We are running Open SUSE 11.0.            2011.01.03 - Thanks to everyone for your help. Luckily I WASN'T the only person responsible for this server, just the nearest. We managed   to resolve this problem, although it may not apply to many others in a   different situation. I'll detail what we did.      We unplugged the server from the net. It was performing (attempting to   perform) a Denial Of Service attack on another server in Indonesia,   and the guilty party was also based there.      We firstly tried to identify where on the server this was coming from,   considering we have over 500 sites on the server, we expected to be   moonlighting for some time. However, with SSH access still, we ran a   command to find all files edited or created in the time the attacks   started. Luckily, the offending file was created over the winter   holidays which meant that not many other files were created on the   server at that time.      We were then able to identify the offending file which was inside the   uploaded images folder within a  website.      After a short cigarette break we concluded that, due to the files   location, it must have been uploaded via a file upload facility that   was inadequetly secured. After some googling, we found that there was   a security vulnerability that allowed files to be uploaded, within the   ZenCart admin panel, for a picture for a record company. (The section   that it never really even used), posting this form just uploaded any   file, it did not check the extension of the file, and didn't even   check to see if the user was logged in.      This meant that any files could be uploaded, including a PHP file for   the attack. We secured the vulnerability with ZenCart on the infected   site, and removed the offending files.      The job was done, and I was home for 2 a.m.            The Moral   - Always apply security patches for ZenCart, or any other CMS system for that matter. As when security updates are released, the whole   world is made aware of the vulnerability.   - Always do backups, and backup your backups.   - Employ or arrange for someone that will be there in times like these. To prevent anyone from relying on a panicy post on Server   Fault.


If $A$ is closed in $X$ and $B$ is closed in $Y$,   does it follow that $A \times B$ is closed in $X \times Y$ ?

If $A\times B$ is closed in $X\times Y$, then are $A$ and $B$ closed in $X$ and $Y$ respectively?


I'm writing a python script that creates a fishnet in a specified area (parcel shapefile) that accepts user input to create a polygon shapefile that represents a building, and polyline shapefile that represent parking area in the parcel.  In ArcMap, you're able to choose the optional parameter of "Template Extent" that automatically populates the Y-Axis, and Origin Coordinates that the tool requires.  I keep getting this error when running my script:  ExecuteError: Failed to execute. Parameters are not valid. ERROR 000735: Fishnet Origin Coordinate : Value is required ERROR 000735: Y-Axis Coordinate : Value is required Failed to execute (CreateFishnet).   In my CreateFIshnet syntax, using "#" in the origin_coord and y_axis coord results in an error instead of passing the request to the optional {template}.    Is there a way around this? I'd like the optional {template} parameter to take priority, but I'm wondering if I have to create points within the specified area and pass those coordinates to the fishnet parameters?

I can’t use the tool arcpy.CreateFishnet_management because define the parameter “templateExtent” with a shapefile it is not filling automatically the  parameters “originCoordinate” and “yAxisCoordinate”.   import arcpy from arcpy import env env.overwriteOutput = True env.workspace = r"D:\Users\julia\erste_aufg"  #Process: Create Fishnet outFeatureClass = r"D:\Users\julia\erste_aufg\at001l_wien\at001l_wien\wien.shp" cellSizeWidth = '200' cellSizeHeight = '200' templateExtent = r"D:\Users\julia\erste_aufg\at001l_wien\at001l_wien\at001l_wien.shp"  arcpy.CreateFishnet_management(outFeatureClass, "", "", cellSizeWidth, cellSizeHeight, '0', '0', "", "NO_LABELS", templateExtent, "POLYGON")     It is working in the ModelBulider, so something is running in the background of the ModelBulider that it could create the parameters “originCoordinate” and “yAxisCoordinate” when it has a “templateExtent”.  How can I get this tool running in ArcPy by having just the parameter “templateExtent”?  I would be really happy if someone has a solution because I need the Fishnet in a scripttool and cannot go one without because in the end there is a loop so the values of the extent are always different.


A question with just a required tag isn't really a tagged question.  doesn't really explain what topics the discussion is about... it's basically a meta tag. A useful meta tag, but quite not enough tagging.  Whenever I see  on Meta Gaming, , but it would be nicer if it was the asker who did this.

From this quote from , referring to the recent mass retagging here:  It left questions untagged. Yeah, it's meta, so there's required tags but those required tags are meta tags... literally. If a question doesn't have any tags other than the required tag, it's untagged! We don't prevent this, but maybe we should.  Do you agree with the point of view that questions here only consisting of required tags are effectively untagged? Should we prevent questions here on meta from only having one or more of the required tags , , , or ? I'm neutral about it; I just want to see what others think.


I was working on creating a grass plane and during the process of creating it, I made a plane on which the particle system was to be applied and an object - grass blade which is to be dispersed on the plane. I created a small number of varied grass blades and joined them. Upon choosing the group of grass blades ad the hair emission object of the plane, the result appears to be: the grass blades spawn half on one side and the other half on the other side (shown in the picture) and the grass blades sometimes seem to lay horizontally on the plane rather than vertically. The grass blades also overflow the borders of the plane as shown in the picture. best, Jassim

I made a hair particle system and set the Dupli Group to a group of 3 objects. Each of the 3 objects has:   it's origin set to be touching the XY plane (on layer 2) it's Scale applied to 1 and it's Rotation applied to 0     I am trying to get each of the objects to sit directly on top of the ground, but instead, they are centered in the plane, half above the plane and half below the plane:      What am I doing wrong? Here is .


I have a database in full recovery mode with five tables. I accidentally deleted one table. I don't have any old backups. Can I restore the database with five tables?

I mistakenly deleted around 2,000,000 records from a remote SQL Server 2008 table.  The server is not granting me access to the backup files on the server side.   Is there any way to get back these records?


Hi I've spent hours trying all the suggestions listed on Forums on this problem all over the Internet and I still can't get my wireless working. It's very discouraging because it might force me to go back to Windows which I hate. Can someone help?  Perhaps I can give you some information to help identify what the issue is? b43 isn't coming up in my list of drivers...just Broadcom STA which doesn't work.  I think I've removed all the blacklisted stuff.

I'm having serious problems installing the Broadcom drivers for Ubuntu. It worked perfectly on my previous version, but now, it is impossible.   What are the steps to install Broadcom wireless drivers for a BCM43xx card?  I'm a user with no advance knowledge in Linux, so I would need clear explanations on how to make, compile, etc.    lspci -vnn | grep Network showed:   Broadcom Corporation BCM4322 802.11a/b/g/n Wireless LAN Controller [14e4:432b]      iwconfig showed:  lo        no wireless extensions. eth0      no wireless extensions.   NOTE: Answer below is updated every time new information is added and confirmed working.


I have this reference picture that I put into the side view of my project.  I used a cylinder and then booleaned the bottom part to make the cutout. Now my subsurf modifier doesn't work. What is going on here?     I tried insetting and extruding the bottom to see if that would fix anything but it didn't. Did the boolean mess up the subsurf or is it because I have some tris left over?    Here is the subsurf mod view:

I'm pretty new to blender and used it to model a castle and print it. Now I want to extend the model by textures and render it, but even when I render it with basic material i get some strange output.  Does somebody know my error? I already corrected the normals and they look fine.


From what I know, limits only exist if both side limits exist and are equal: $${\lim_{x\to a}f(x) = L}$$ $$if$$ $${\lim_{x\to a^+}}f(x) = {\lim_{x\to a^-}f(x) = L}$$   But can this be applied to limits at infinity? In that case: $${\lim_{x\to \infty}f(x) = L}$$ $$if$$ $${\lim_{x\to +\infty} f(x)} = {\lim_{x\to -\infty}f(x) = L}$$  Is this correct or ${\lim_{x\to \infty}f(x)}$ should be taken as ${\lim_{x\to +\infty}} f(x)$ ?

I am studying limits at infinity, and I have a doubt about evaluating them. From what I know, limits only exist if both sides of the limit exist and are equal. For example, take a look at the following limit:  $$\lim_{ x\to \infty}\frac{x}{e^{-x}}$$  As $x \to +\infty$ the function goes to $+\infty$. However, as $x \to -\infty$ the function goes to $0$.   Does this mean that the limit does not exist or I only have to evaluate the limit as x goes to $+\infty$?


I want to extract a zip archive to "C:\\" (just for testing purpose). Therefore I need admin rights, so I am trying to elevate the current user to get admin rights.  if __name__ == "__main__":     ASADMIN = 'asadmin'      if sys.argv[-1] != ASADMIN:         script = os.path.abspath(sys.argv[0])         params = ' '.join([script] + sys.argv[1:] + [ASADMIN])         shell.ShellExecuteEx(lpVerb='runas', lpFile=sys.executable, lpParameters=params)         main()   The invoking message from UAC is comming as it should but when I want to extract the zip I am still getting "IOError: [Errno 13] Permission denied".  What am I doing wrong here?

I want my Python script to copy files on Vista. When I run it from a normal cmd.exe window, no errors are generated, yet the files are NOT copied. If I run cmd.exe "as administator" and then run my script, it works fine.  This makes sense since User Account Control (UAC) normally prevents many file system actions.  Is there a way I can, from within a Python script, invoke a UAC elevation request (those dialogs that say something like "such and such app needs admin access, is this OK?")  If that's not possible, is there a way my script can at least detect that it is not elevated so it can fail gracefully?


Using 18.04 LTS. Update this morning shows a 10.2 Mb file to be downloaded but there are no details of the update nor any technical description. Seems suspicious to me, is it?

Today I received an update notification for three updates but update manager doesn't say what updates are they.    Does anyone have a clue what this is about? How am I to check what is to be updated?


I have the dreamspark MS license. However, everytime I have to install Windows on my PC, I get many updates and this process is long and boring. Is there any way to download the lastest Windows ISO with updates?   I'm trying to install Windows 7 (but Windows 8 would also be helpful).  Note: I don't want just download windows. I want to download the OS with the lastest updates, those that are downloaded with Windows update after installing it!!  Thanks!

Possible Duplicate:          I have lost my Windows 7 installation DVD, but I do have the license key. How can I get a Windows 7 DVD? Can I download an ISO image somewhere? While installing can I use my original Windows 7 Key?


I have always had a doubt in the definition of the Newton's first law. In general, it is stated in a form like:     An object at rest remains at rest, or if in motion, remains in motion at a constant velocity unless acted on by a net external force.   However, we know that there are reference frames in which the first law is not valid, these are the called non-inertial reference frames. So the first law should be stated as "there are reference frames in which an object at rest remains at rest, or if in motion, remains in motion at a constant velocity unless acted on by a net external force". But the most books don't care about this and state the first law like the first way, what to me is incorrect.  I understand a high school book doesn't talk about non-inertial reference frames (this is not simple), but I have already seen a lot of undergraduate and graduate physics books do this. What do you think? This statement is really incorrect?

If you consider  as laws, then there must be independent definitions of  and  but I don't think there's such definitions.  If you consider them as definitions, then why are they still called laws?


How can I print all of the output on the same line? Something like ",,,key, value". The below creates a newline for every preceding ','.  for i in range(0, depth):     print(',') print("{}, {}".format(key, value))

I'd like to do it in Python. What I'd like to do in this example in C: #include <stdio.h>  int main() {     int i;     for (i=0; i<10; i++) printf(".");     return 0; }  Output: ..........  In Python: >>> for i in range(10): print('.') . . . . . . . . . . >>> print('.', '.', '.', '.', '.', '.', '.', '.', '.', '.') . . . . . . . . . .  In Python print will add a \n or space, how can I avoid that? Now, it's just an example, don't tell me I can first build a string then print it. I'd like to know how to "append" strings to stdout.


So I have a div footer on my page that lets say has a height of 200 pixels. Now this div has a button that reveals some html objects that are within the div and therefore increases the height of the div, to lets say, 400px.  So my div that was originally 200px is now 400px and is aligned to the bottom of the page. The problem is that when the div is expanded my browser doesnt automatically scroll down the window in order to show all the div. As a result, i only see the top 200 pixels of my div ( the original size ) and I have to manually scroll down my browser window in order to see the complete div.  Is there a way using html css that I can make my browser automatically scroll down when the div expands? If not, I guess it is possible with javascript at least..

Hopefully, this will be an easy answer for someone with Javascript time behind them...  I have a log file that is being watched by a script that feeds new lines in the log out to any connected browsers.  A couple people have commented that what they want to see is more of a 'tail -f' behavior - the latest lines will always be at the bottom of the browser page until the viewer scrolls back up to see something.  Scrolling back to the bottom should return you to the auto-scrolling behavior.  My google strikeout on this one is - hopefully - just a matter of not knowing anything at all about javascript and therefore, not knowing what keywords to search for.  I don't need a complete solution - just a 'close enough' that lets me jump in and get my hands dirty.  EDIT:  I've been attempting the scrollTop/scrollHeight idea, but am clearly missing something.  I've done next to nothing with Javascript, so again I'm probably asking very low-level questions:       This was one of many permutations.  Obviously, I can't output the log line-by-line in javascript, but I'm just trying to see the correct behavior.  What's the missing link I need here?  EDIT AGAIN: This has turned into a far more interesting problem that I first expected.  The code suggestion using window.scroll does do the trick.  I started playing with restricting the scroll to only take place when the browser was at the bottom of the document body.  This is easy enough to do in theory, but in practice it hits a snag:  Every time you get new text from the server, the size of the body increases and your current scroll position is no longer at the bottom of the document.  You can no longer tell the difference (using scrollHeight, clientHeight and scrollTop) whether the user has scrolled up or if the text has just shot beyond their view.  I think that if this is going to work, I'm going to have to commit myself to having a JS event that fires when the user scrolls and turns off scrolling if they are above the bottom of the window, but turns it back on if they have scrolled down to the point where they are effectively at the bottom of the view.  I'm looking at the onScroll event and, given that the math on the variables I mentioned works out pretty well, I think I am on the right path here.  Thanks for your input, everyone!


In order to understand the technology in a digital camera, I considered the following question:  How does ISO setting change CCD/CMOS sensor behavior?  For example, does ISO setting affect the amount of charge that each photon generates in the sensor, or does it merely change the amplification of a fixed charge from each photon.  High end cameras allow for ISO in the range from 100 to e.g. 51200, thus a factor from 1 to 512, so it appears that the electronics allows for a pretty large range.  A reference to an article would be appreciated.

If I change the ISO settings on my camera, obviously the gain of the system is increased, amplifying the signal from the sensor. What's not clear to me is where the amplification takes place. I see several possibilities:   In the sensor, by increasing voltage or some other mechanism Via an analog amplifier outside of the sensor Digitally, after the signal has been digitized, but before storing data in the RAW file As a parameter applied solely in creating an image from RAW   If #4 is true, then you could take a 4-stop overexposed RAW picture at ISO 1600, and then in post processing produce a JPEG at ISO 100 that would be the same as if the original photo had been shot at ISO 100.  If #1 or #2 is true, then a RAW file shot at ISO 1600 would actually contain more information about shadows, and an ISO 100 RAW would contain more information about highlights.


I am interested why processes are grouped additionally while having already a PPID and PID. What's the advantage of process groups?

What's the difference between a process group and a job? If I type pr * | lpr then is it both a process group as well a job?  What exactly is the difference between a process group ID and a job ID?  Edit: I know it appears similar to , but it is slightly different. Also, I didn't understand this concept from this thread.


Below is a program given for assignment. Request you to help on the below output getting as "Expected output". It providing error as "Exception in thread "main" java.lang.StackOverflowError".  class A {     {         new B();     }      static class B     {         {             new A().new C();         }     }      class C     {         {             System.out.println("Expected output");         }     } }  public class MainClass {     public static void main(String[] args)     {         new A();     } }

What is a StackOverflowError, what causes it, and how should I deal with them?


I have two processes that run using Python and SQlalchemy.  One process runs continously and inserts or updates certain rows in a MySQL table.  Another process runs once every day, reads the rows from the table, moves data into a CSV and deletes the rows. It deletes all the rows through one delete statement  Once in a while I get "Lock Wait Timeout Exceeded" error from MySQL.  What are the advantages and disadvantages to delete one row at a time vs deleting all through one statement ?  In my process that runs once every day, I dont care if it takes more time.   Thanks

I am trying to delete several rows from a MySQL 5.0.45 database:  delete from bundle_inclusions;   The client works for a while and then returns the error:  Lock wait timeout exceeded; try restarting transaction   It's possible there is some uncommitted transaction out there that has a lock on this table, but I need this process to trump any such locks.  How do I break the lock in MySQL?


Grammar Nazi is usually how they describe someone who corrects other people's grammar (or spelling, or other errors).  Is there any expression that shows such a person in a positive light?  I ask because the person being corrected might actually be grateful about it and want to show this Grammar Nazi in a positive light.  For example:      John Doe is a real ____ . If he hadn't pointed out all the mistakes in my résumé , everyone would think I was a fool and I'd still be looking for a job.   I'm not looking for terms implying generic smartness. This term should specifically imply John Doe is good at English (or any other language).    EDIT:  asks for an "alternative expression" which should be  "funny, slightly reproachful, but not really offensive". It accepts the answer 'Grammar police', and other top answers include 'pedant' and 'fascist'.  I'm looking for a positive term. And those answers aren't applicable here.

I'm not a native English speaker, but I do understand and personally appreciate the use of the term "xyz Nazi" to say that someone is a bit dogmatic about their point of view, without necessarily offending them. A related question here on SE is:    But most often, my writing doesn't address only English speakers, but also others. Being a native German speaker (although not from Germany), I'm a bit more sensitive to how this might be received with my every day audience.  What would be an equivalent term with a similar semantics (funny, slightly reproachful, but not really offensive)?


I'm teaching myself 5e from absolute scractch, and I'm trying to roll an attack with a shortbow. AC modifiers + initiatives are fine, but calculating the actual damage is something that's tripping me up.  Does '5(1d6+2) piercing damage' mean Roll 1d6 + 2 for a maximum of 5 damage or something else entirely?  Thanks!

My friends and I are very new to D&D, played like 3 times. In a monster's stats next to weapon damage it says stuff like "+11 to hit" and "Hit: 5 (1d8+1)". For the premade characters it just says things like "+4, 2d6 + 2 slashing", though. Why are there two "hit" numbers for monsters? Which do I use for the d20 roll to hit against a target's AC?  I mean for example like in the Ogre entry in the "" article on monsters.


When I dropped my iPhone on the sink it didn't crack but it did break inside.  I can't use my iPhone. I can turn it on but it isn't fully functional. There are lines and white blocks on the screen.  I am wondering, if I have a warranty, can I get it repaired for free?

My 1 year warranty has just ended within the last week and my daughter dropped my iPad 2 which has resulted in a cracked screen.   Is there a one-time physical damage replacement policy in Washington state, as there is in others?


I am analyzing the past tense of "simple past" and I do not know if the form "were propped up" indicated in the sentence is composed of a verb conjugated in "simple past" and followed by an adjective, or on the contrary, it is part of a clause in passive.  Her flat cloth slippers were propped up on a foot-warmer, and a cat reposed on her lap.

He is loved.   This is something that I've always kind of wondered.  In a sentence like this, is loved a verb or an adjective? Can it be considered either?


Are camera sensors sensitive to UV light? I thought that all modern cameras have UV protection 'built in'.   Do UV filters serve any purpose nowadays other than protecting the lens from dirt, scratches and finger prints? If so, why don't we just put clear filters on the lens?

I'm usually very good at getting water/finger marks on lens, so I must use something for protection. Is there any downside of using an UV filter instead of a protector filter?  Example: Hoya HD Protector or Hoya HD UV?


I already installed gnome-clocks and added some new time zones in it.   In addition, I installed gnome-tweak-tool and enabled Ubuntu appindicators.   I still don't see an option to add world clocks to the top bar. What am I missing?

I make extensive use of the multiple timezone clock feature in 16.04.  After upgrading to Ubuntu 18.04 I found various guides that installing GNOME Clocks and adding time zones I should see them in the dropdown when I click the clock on the taskbar.  However it isn't showing up in there, despite restarting a few times.  I also installed GNOME Weather and its section shows now in the clock dropdown.  Has anyone else had this problem? Ideas on how to fix this?


I am reading Topology by James Munkres and I got the following question:  I understand that a is an element and {a} is a set containing the element a. I can memorize it, but as I reason it I think that I do not have the difference entirely clear in my head.   This is because I thought that a set itself is only defined by the elements it is made of. That is to say, that the set itself it is nothing other than the elements it is made of. Now the only difference I perceive from a and {a} is that the later would content the elements of the  empty set (since it is assumed that the empty set is  a subset of all sets).   If that is not the only difference between both notions, how would you explain it? Again, I can memorize that they are not different and that visually they are not. But I think that I can understand deeper the concept of a set if I get the difference it has with an element very clear. Thanks.

Is ∅ equivalent to {∅}? I think they are, but I am not sure? If anyone could clarify, that would be great. Thank you!


Harry takes the Hogwarts Express to get to school all the six years when he's attending Hogwarts (with the exception of his second year, of course; but he was trying to get on it) and boards the train from platform 9¾.   Are there any wizarding trains other than the Hogwarts Express, and are there any platforms other than 9 ¾ that witches and wizards can take from King's Cross to their world?

In the Pottermore article on  it's mentioned that other fractional platforms exist (7 1/2, for instance). Is it ever stated elsewhere where these platforms lead? Perhaps you could get a connection from your hometown by accessing one of these platforms?


If I were given $\lim_{n\to \infty}(1 + \frac{1}{n})^n$, and asked to solve, I would do so as follows:  $$\lim_{n\to \infty}(1 + \frac{1}{n})^n$$ $$=(1 + \frac{1}{\infty})^\infty$$ $$=(1 + 0)^\infty$$ $$=1^\infty$$ $$=1$$  I'm aware that this limit is meant to equal to $e$, and so I ask:     why don't I get $e$ when I solve $\lim_{n\to \infty}(1 + \frac{1}{n})^n$?

I am trying to identify what the flaw is exactly when reasoning about a limit such as the definition of $\mathbf e$:  $$ \lim_{n\rightarrow \infty}\left(1+\frac{1}{n}\right)^n={e} $$  Now, I know there are ways of proving this limit, such as by considering the binomial expansion of $(1+\frac{1}{n})^n$ and comparing that to the Maclaurin series of $e$. So to make this clear, I am not looking for a proof of the limit definition of $e$.  I tried searching for "limit laws/rules" but none of the rules I found described the above case. Hence, I am looking for a specific rule (or perhaps a certain perspective) that will help me realize why the above does not in fact evaluate to 1.  My train of thought is as follows: at a first glance, if I wasn't already familiar with what the limit evaluates to, I probably would evaluate the expression inside the brackets first, and then apply the limit to the power. So, $$\displaystyle\lim_{n\to\infty}\frac{1}{n}=0\quad\text{and then}$$  $$\displaystyle\lim_{n\rightarrow \infty}\left(1+0\right)^n=\lim_{n\to\infty}1^n=1$$  Why is my reasoning flawed?


Let $\alpha,\gamma$ be ordinals and $A$ be a set of ordinals. Then $$\gamma<\alpha+\sup\limits_{\beta\in A}\beta\implies\exists\beta\in A:\gamma<\alpha+\beta$$   This problem arises when I prove the theorem:     Let $\alpha,\beta$ be ordinals and $A$ be a set of ordinal. Then $\sup\limits_{\beta\in A}(\alpha+\beta)=\alpha+\sup\limits_{\beta\in A}(\beta)$   I'm almost done except for one minor point: $\gamma<\alpha+\sup_\limits{\beta\in A}\beta\implies\exists\beta\in A:\gamma<\alpha+\beta$. This result seems quite obvious, but I don't know how to prove in spite of several attempts.  Could you please shed me some lights on how to prove $\gamma<\alpha+\sup\limits_{\beta\in A}\beta\implies\exists\beta\in A:\gamma<\alpha+\beta$? Thank you very much!

My idea is to prove that $\alpha+ \sup\limits_{β∈A}(β)$ is the supremum of $\{α+β\mid β∈A\}$. While I'm able to prove that $\alpha+ \sup\limits_{β∈A}(β)$ is a upper bound of $\{α+β\mid β∈A\}$, I failed to show that $\alpha+ \sup\limits_{β∈A}(β)\le\gamma$ where $\gamma$ is an upper bound of $\{α+β\mid β∈A\}$. The addition of ordinals is defined as follows $\alpha+0=\alpha$, $\alpha+(\beta+1)=(\alpha+\beta)+1$, and $\alpha+\beta=\sup\limits_{\gamma<\beta}(\alpha+\gamma)$ if $\beta$ is limit. My attempt: For all $\beta\in A,\beta\le\sup\limits_{β∈A}(β)$, then $\alpha+\beta\le\alpha+ \sup\limits_{β∈A}(β)$ and thus $\alpha+ \sup\limits_{β∈A}(β)$ is a upper bound of $\{α+β\mid β∈A\}$. Assume that $\gamma$ is an upper bound of $\{α+β\mid β∈A\}$, then $α+β\le\gamma$ for all $β∈A$. My questions:  Please leave me some hints to complete my proof!  I meet another proof of this theorem on the Internet:    Could you please elaborate on the sentence Since set inclusion is the ordering, the two are equal. I'm unable to understand what this sentence means. Thank you so much for your help!   For an ordinal $α$ and a set $A$ of ordinals:  $\sup\limits_{β∈A} (α+β) = α+\sup\limits_{β∈A}(β)$  $\sup\limits_{β∈A} (α\cdot β)=α\cdot \sup\limits_{β∈A}(β)$


Suppose that $P_1$ and $P_2$ are coprime between them in $\mathbb{K}[X]$. Show that    $$ \ker ( (P_1 \times P_2 )(f) )=\ker(P_1 (f)) \oplus \ker(P_2(f)).$$   I tried by starting off by showing that the right hand equality is true, that is $\mathbb{K}[X]$ is indeed equal to $\ker(P_1 (f)) \oplus \ker(P_2(f))$.  My first attempt was to show that $$\ker(P_1 (f)) \cap \ker(P_2(f))= \{ 0 \} .$$  But I got nowhere. I think I could have used the Bezout theoreme, that is:      If $P_1$ and $P_2$ are coprime, then $\exists U,V \in \mathbb{K}[X]$ so that $P_1U(X) + P_2V(X)=1$   But nothing comes to my mind.

I have a question related to the Primary Decomposition Theorem for a vector space under a linear transformation.  The following question is a direct corollary of this theorem.  However, I wish to prove it without calling upon theorem.  I am currently studying for a comprehensive exam and ran across this question.  I never really felt comfortable with the proof I saw of the Primary Decomposition Theorem so I hoping with your help with this problem I will understand this particular problem and better understand that proof as I believe their proofs will be essentially the same techniques.   Question:  Suppose we have a linear transformation $T: \mathbb{R^n}\to \mathbb{R^n}$ with minimal polynomial $m(x)=f(x)g(x)$ and $f(x),g(x)$ are relatively prime.  Show that we can write $\mathbb{R^n}=M\oplus N$ where $M$ and $N$ are $T$-invariant subspaces s.t $f(x)$ is the minimal polynomial for $T|_M$ and $g(x)$ is the minimal polynomial for $T|_N$.   So I know that I want to use $M=ker(f(T))$ and $N=ker(g(T))$ but after that I really don't have much.  Since this isn't a homework problem for a class I am essentially looking for someone to present me a proof of this simpler question and walk me through their logic so that I can hopefully understand the general theorem and its proof.  Thanks in advance for the help!


In order to remind myself when I try to use shopt in Zsh instead of setopt, I created the following alias, testing it first at a shell prompt:  $ alias shopt='echo "You\'re looking for setopt. This is Z shell, man, not Bash."'   Despite the outer single quotes matching and the inner double quotes matching, and the apostrophe being escaped, I was prompted to finish closing the quotes with:  dquote > _   What's going on?  It appeared that the escaping was being ignored, or that it needed to be double-escaped because of multiple levels of interpretation...  So, just to test this theory, I tried double-escaping it (and triple-escaping it, and so on) all the way up until:  alias shopt='echo "You\\\\\\\\\\\\\\\\\\\\\\'re looking for setopt. This is Z shell, man, not Bash." '   and never saw any different behavior.  This makes no sense to me.  What kind of weird voodoo is preventing the shell from behaving as I expect?  The practical solution is to not use quotes for echo, since it doesn't really need any, and to use double quotes for alias, and to escape the apostrophe so it is ignored when the text is echoed.  Then all of the practical problems go away.  Can you help me?  I need resolution to this perplexing problem.

I recently learned about , but am having trouble making it work with relatively sophisticated commands. For example, I would like to ask watch to run the following command on zsh every three seconds*: for x in `command_1 | grep keyword | cut -d' ' -f1`; do command_2 "word[word=number]" $x; done  as you can see the line above includes single quotes, double quotes, among other special characters. So I tried: watch -n 3 "for x in `my_command | grep keyword | cut -d' ' -f1`; do command2 "rusage[mem=7000]" $x; done"  but then I got:  no matches found for x in !@#$# ....; done  I tried other combinations without success. Here's one of those attempts: watch -n 3 "for x in $(bjobs -w | grep pre_seg | cut -d' ' -f1); do bmod -R "rusage[mem=7000]" $x; done"  which also results in a similar error. Any ideas how to make this work?  *I would also be intersted in solutions that work on bash


I have a program written in C#, console application. A .exe file is created and when executing the command window opens, writes the output and closes as usual. My problem is that I may need to see the output in the cmd (not always). Is there any command (as I call my exe file through cmd in order not to close the command prompt that specific time only)??

My problem is that in Windows, there are command line windows that close immediately after execution. To solve this, I want the default behavior to be that the window is kept open. Normally, this behavior can be avoided with three methods that come to my mind:   Putting a pause line after batch programs to prompt the user to press a key before exiting Running these batch files or other command line manipulating tools (even service starting, restarting, etc. with net start xy or anything similar) within cmd.exe(Start - Run - cmd.exe) Running these programs with cmd /k like this:  cmd /k myprogram.bat   But there are some other cases in which the user:   Runs the program the first time and doesn't know that the given program will run in Command Prompt (Windows Command Processor) e.g. when running a shortcut from Start menu (or from somewhere else), OR Finds it a little bit uncomfortable to run cmd.exe all the time and doesn't have the time/opportunity to rewrite the code of these commands everywhere to put a pause after them or avoid exiting explicitly.   I've read  about changing default behavior of cmd.exe when opening it explicitly, with creating an  and manipulating its content in these locations:  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Command Processor\AutoRun HKEY_CURRENT_USER\SOFTWARE\Microsoft\Command Processor\AutoRun   (The AutoRun items are _String values_...)  I put cmd /d /k as a value of it to give it a try, but this didn't change the behaviour of the stuffs mentioned above at all... It just changed the behaviour of the command line window when opening it explicitly (Start-Run-cmd.exe).   So how does it work? Can you give me any ideas to solve this problem?


Sorry, I know this is probably simple and covered in another post but I couldn't find it so:  I want to iterate through two lists and then store a result in an array based on the position of the inputs. So, for example:  z = np.array(len(xlist), len(ylist))  for x in xlist:   for y in ylist:     z[index of x, index of y] = f(x,y)   Thanks!

How do I access the index in a for loop like the following?  ints = [8, 23, 45, 12, 78] for i in ints:     print('item #{} = {}'.format(???, i))   I want to get this output:  item #1 = 8 item #2 = 23 item #3 = 45 item #4 = 12 item #5 = 78   When I loop through it using a for loop, how do I access the loop index, from 1 to 5 in this case?


I am looking for a way to quickly switch between keyboard apps while using gboard. My phone is a redmi 5. For e.g if I am writing a message I prefer gboard. But when I have to write code I want to quickly switch to hackers keyboard app. Incidentally on the latter I have the option to jump back to gboard... I want to be sure that there is no option on gboard to do the same.

I have two languages on Gboard and when I want to switch between them, I have to press the globe button. Is there anyway to switch language by swiping spacebar? I've seen this feature on Samsung Keyboard and I was wondering if it's available on the new Gboard.


I heard that $e$ can be defined as the limit as n approaches infinity of $(1 + 1/n)^n$, but I also heard that $e$ is also defined as the sum of the reciprocals of the factorials from $0$ to $\infty$. How are these the same?

How can it be proved that the Euler constant equals the limit of the sum of all $\frac{1}{k!}$ when $k$ goes from $0$ to $+\infty$ ?


I don't know why the following program is generating this error-> clone has protected access in Object. Can't the derived class access the protected methods of the Object class?  If I skip this statement cloned.id=(String)id.clone(); the program compiles successfully!    class Example implements Cloneable{ String id; void display(){     System.out.println("ID="+id);     } public Example clone() throws CloneNotSupportedException{     Example cloned;     cloned=(Example)super.clone();     cloned.id=(String)id.clone();               //troublemaker     return cloned;     } } class CloneInterface{     public static void main(String args[]){         try         {         Example e1=new Example();         e1.id="a";         Example e2=e1.clone();         e2.id="b";         e1.display();         e2.display();         }         catch(CloneNotSupportedException e)         {         e.printStackTrace();         }     } }

The keyword protected grants access to classes in the same package and subclasses ().  Now, every class has java.lang.Object as superclass ().  Hence I conclude that every class may access java.lang.Object's methods even if they are protected.  Take a look at the following example:   public class Testclass {   public Object getOne() throws CloneNotSupportedException {     return this.clone();   }   public Object getTwo() throws CloneNotSupportedException {     return ((Object) this).clone();   } }   While getOne() compiles fine, getTwo() gives   Testclass.java:6: clone() has protected access in java.lang.Object         return ((Object) this).clone();   I neither understand why getTwo() doesn't compile nor what's the difference (regarding the access of java.lang.Objects members) with getOne().


I've heard of certain properties being attributed to things such as dragon tears and scales, are there any established properties for dragon bones in crafting or other applications?

My party recently acquired some dragon bones. We split up the skeleton. I got the head and neck. One got the ribs and front legs. One got the wings and feet and one got the back legs and tail. I bought the rib cage for 125 gp. I don't know if that was a good idea but I did it. I want to know how I can use the neck bones, skull, and ribs.  Can anyone tell me what to do in this situation? Someone once suggested I use the ribs to reinforce my shield, but I don't know if that's allowed by the rules.   What are the guidelines around what can be done with dragon bones? I know I can just use them for cool decorations, but is there any rules support from getting any kind of benefit out of them?


I was playing around with the family of sequences $s(x)$ defined for $x > 0$ as $s(x)_0 = x$, $s(x)_{n+1} = \log(1+s(x)_n)$ and I noticed a strange behavior. Specifically, regardless of the choice of $x$, $s(x)_{10^n} \approx 2\cdot 10^{-n}$ as $n$ grows:  > let logs x = x : logs (log (1 + x))  > logs 1000 !! 1000 2.0066131337990703e-3 > logs 1000 !! 10000 2.0008131530487204e-4 > logs 1000 !! 100000 2.0000966401761077e-5 > logs 1000 !! 1000000 2.000011198587142e-6   Based on this observation, I am wondering whether $n s(x)_n \rightarrow 2$ for all $x > 1$ and if so, why.

Suppose $x_{1}>0$, and consider the sequence, $\{x_{n}\}$ defined as follows: $$x_{n+1}=\log(1+x_{n}) \quad n\geq 1 $$ Find the value of $\displaystyle \lim_{n \to \infty} nx_{n}$  I am having trouble solving it. One thing is clear, that since $x_{n}>0$ and $x_{n+1} < x_{n}$, we can have a sequence which converges an $f$ which satisfies $f=\log(1+f)$, so that $f=0$. Any way as to how we can proceed from here.


Let a Pythagorean triple $(\xi,n,\zeta)$.Prove that at least one of $\xi,n$ is divided by $3$ and that at least one of $\xi,n, \zeta$ is divided by $5$.  That's what I have thought:  We suppose that : 1)$\xi=3n+1 \text{ and } n=3m+1$  2)$\xi=3n+1 \text{ and }n=3m+2$  3) $\xi=3n+2 \text{ and } n=3m+2$  and we show that at no of the above cases it is possible that $\xi^2+n^2=\zeta^2\text{ ,because the remainders will be } 2,8,9, \text{ but  the only possible remainders that can give } n^2,\text{ divided by } 9, \text{ are } 0,1, \text{ so it is a contradicton.}   $  Similarly,we can show that at least one of $\xi,n, \zeta$ must be divisible by $5$.  Is the way I thought right??  Is there also an other way?

Show that if $x$, $y$, $z$ are integers such that $x^2 + y^2 = z^2$, then at least one of them is divisible by $2$, at least one is divisible by $3$, and at least one is divisible by $5$.  I know that $x,y,z$ are sides of a right-angled triangles. If I start putting values, then I can show, but have no clue about mathematical approach.  How do I solve it mathematically, using modular arithmetic?


The Chancellor undoubtably did some really evil things (and/or made Vader do them) after the scene in question, but given only what happened leading up to this scene I wonder if Windu was in violation of the Jedi code or laws of the Republic by trying to kill Chancellor Palpatine.   Chancellor Palpatine was the freely elected leader of the Republic (he was elected to office and his term was extended by a democratic vote). If he had killed anyone or broken any laws, I don't think evidence of that was shown to the viewer, or at least not to Windu, yet Windu:   trespassed onto his private property,  decided to "arrest" him based on an unsubstantiated rumor that he used "the dark side" (which I have a hard time imagining was against any law anyway),    horribly disfigured the elderly man and  subsequently decided that Palpatine was "too dangerous to let live" after he defended himself.    He attempted to kill Palpatine as he lay writhing in pain and begging for his life.    I can understand that this was done to help humanize Anakin's decision to save the Chancellor, but I can't see how Master Windu was representing "good" and the Chancellor or Anakin "evil".   It seems like Windu was acting criminally and attempting to commit murder (?). I don't see how Anakin's protection of the Chancellor or the Chancellor's self-defense could be considered evil or unethical.

If the Jedi Order had arrested Palpatine, would the court have declared Palpatine guilty quickly based on proof that he was a Sith? Is there any rule stating that?  Notes:   The word quickly is important because finding proof of his political crimes would be difficult and time-consuming (it could take decades). I am assuming that the Jedi can prove that Palpatine is a Sith (e.g., using a security hologram of his conversation with Anakin, in which Palpatine declares that he is one). For this question, I am also removing all of Palpatine’s murders of Jedi from the equation.   Update: This is a generic question about any Sith, not just Palpatine. In other words, could a Sith introduce himself to the Republic to have a peaceful life demanding protection from the Jedi if the case arises?


Does anyone know how to find the exact sum of  $$ \sum_{n = 1}^{\infty} \frac{(-1)^{n + 1}}{n} $$  I've only taken second semester calculus and don't see how to go about computing this sum. The only way that I know how to find the sum of an infinite series is if it is a geometric series.  Using WolframAlpha, I found that the sum for this series is $\log(2)$.

I know that the harmonic series $$\sum_{k=1}^{\infty}\frac{1}{k}  = \frac{1}{1} + \frac{1}{2} + \frac{1}{3} + \frac{1}{4} + \frac{1}{5} + \frac{1}{6} + \cdots + \frac{1}{n} + \cdots \tag{I}$$ diverges, but what about the alternating harmonic series   $$\sum_{k=1}^{\infty}\frac{(-1)^{k+1}}{k}  = \frac{1}{1} - \frac{1}{2} + \frac{1}{3} - \frac{1}{4} + \frac{1}{5} - \frac{1}{6} + \cdots + \frac{(-1)^{n+1}}{n} + \cdots \text{?} \tag{II}$$  Does it converge?   If so, what is its sum?


Have $(U,V)$  be a pair of Bivariate Gaussian variables with mean $0$, variance $1$ and $Cov(U,V) = ρ$ where  $0 < ρ < 1$  I'd like help finding the density of $U+V$  So far I have tried to use $P(U+V<=t) = E(P(U+V<=t | V))$ but a am not having much success in advancing. Any help would be appreciated.  Note: This is not a homework problem, but a problem I am doing to help study.

Suppose $x_1\sim\mathcal N(2,0.5),x_2\sim \mathcal N(2,3),$ and $x_3\sim \mathcal N(2.5,7)$ with correlations $\rho_{(1,2)}=0.3,\rho_{(1,3)}=0.1,$and $\rho_{(2,3)}=0.4.$ What is the distribution  of    $x_1+x_2+x_3?$ $x_1+ (3\times x_2)+x_3?$  $x_1+x_2+(0.5\times x_3)?$  Solutions: The distribution of $x_1+x_2+x_3 =\mathcal{N}(6.5,15.275)$. The distribution of $x_1+(3\times x_2)+x_3=\mathcal{N}(10.5,30.077)$ The distribution of $x_1+x_2+(0.5\times x_3)=\mathcal{N}(5.25,8.005)$  But I want to know what is the distribution of $(2\times x_1)-(3\times x_2)-x_3$ and $x_1+x_2-(2\times x_3)?$  The distribution of $(2\times x_1)-(3\times x_2)-x_3$ is $\mathcal{N}(-4.5,41.8407).$   The distribution of $x_1 +x_2-(2\times x_3) $ is $\mathcal{N}(-1,24.1544)$


Bender Rodriguez. The lovable robot with a SERIOUS alcohol problem.  One thing always perplexed me, though. How does he store everything?     How did he get all these treasures? He stored them in his abdomen for years on end. But many of these riches are far larger than his midsection (see the bender to the right, one row back, and the bender one back and one toward the center of the pirate).  And we see him do this with his majestic midriff multiple times throughout the series.   But how is this terrific thorax possible? In- and Out-Of-World explanations welcome.

Bender often pulls large objects from his torso cupboard, but how deep or how much empty space is he capable of storing? Can he bend space around the perimeters of the frame of his torso's door? If that is the case, does it also bend time? I suppose he might bend in more ways than one...


I have set of linux folders and I need to get the permissions of the folders numerically.  For example in the below directory, I need to what is the permission value of the folder... Whether 755, 644 or 622 etc...  drwxrwsr-x 2 dev    puser 4096 Jul  7  2014 fonts

In FreeBSD and also in Linux, how can I get the numerical chmod value of a file? For example, 644 instead of -rw-r--r--? I need an automatic way for a Bash script.


I have a chat client that launches another window when '.play' is sent in. The relevant code follows:  BoardFrame bframe = new BoardFrame(); bframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); bframe.setSize(300,600); frame.setVisible(false); bframe.setVisible(true); BoardPanel bpanel = new BoardPanel(); bpanel.setSize(200,500); bpanel.setOrientation('v'); bpanel.setBackground(Color.GREEN); bpanel.paintComponent(bpanel.getGraphics()); bpanel.setVisible(true); bframe.getContentPane().add(bpanel,"Center"); bframe.pack();   BoardPanel is a class that extends JPanel and BoardFrame is a class that extends JFrame. Frame will be deleted, but for now i just set it to not visible.  I just dont want to go messing around in those other classes if the solution is a quick one here.   Also this is my first post on here so please forgive the hideous formatting.

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


Does anyone know the story about an astronaut stranded on an alien planet who discovers an alien habitat or some sort, that slowly transforms him into  an alien being in order to survive its toxic atmosphere and to enable him to take in the alien food?

This is a story that was read on BBC radio about thirty years ago, and this is about as right as I can remember it: The human pilot of a spacecraft is doing some reconnaissance on an alien planet. He crashes but survives. For some reason, no one will know where to look for him. He sees something in the distance that looks like a building of some sort. When he gets there, it seems to be a home. Very much like a human home. There's furniture, but it's strange and uncomfortable . There's food, but it's inedible. There's a faucet but what comes out of it seems more like acid. Everything looks as though it should be right, but it's not. He leaves the house, wanders and after a few days is desperate for water. But there isn't any water anywhere. He's close to death, crawling on the ground and then something happens. There are cracks in the soil and there appears to be water bubbling up from perhaps some underground stream. The water revives him. He goes back to the house and tries the food again. It's delicious and he eats enough to gain back his strength. Then he decides to try the water again. It's pure and wonderful. He takes a shower and the last line of the story is how refreshing the water is on his skin and something about him lifting his tail.


Is it something like they are by default added to every directory created to facilitate movement outside?

when I used ls -a to view hidden files in folder there were 2 hidden files created by default what is the significance of this two files . and ..?  ls -a   Produces  .  ..


Is there a way of taking a snapchat filter off a saved image? Its a leopard nose and ears and would like to know if i can get them off or if any one else could?

I took a great picture of the sky the other day but it was on snapchat and i covered a tree by painting yellow streaks over it on the snap, that's the only pic I saved to my phone but I wanted to know if there was a way to remove the yellow streaking? can it be done with an online program? thanks


Higgs Boson detected at LHC is massive. It has high relativistic mass means it has non-zero rest mass.  Higgs Boson gives other things rest mass. But, how does it get rest mass by itself?

If the Higgs field gives mass to particles, and the Higgs boson itself has mass, does this mean there is some kind of self-interaction?  Also, does the Higgs Boson have zero rest mass and so move at light-speed?


What is the rule should the Goalkeeper save the penalty, (as in a case I experienced), the ref blows his whistle then the ball which went away from goal had some backspin on it and slowly proceeded to make its way into the net while the keeper was celebrating winning the shoot out with his team.  Objections from the opposing Manager resulted in the kick being taken again and this time they scored and we went from winning to losing the shot out.  Anyone know what should have happened?

If, during kicks from the penalty mark, the ball hits the goalpost and lobs outside the penalty area and then returns back into the goal without touching any player, will it be considered a goal or not?    Please provide a reference to IFAB laws if possible.