What's the proper way to round a decimal in 2 digits but as zero. i.e if the number is 561.82 to be rounded as 562.00 ?

What I would like is a method to convert a double to a string which rounds using the half-up method - i.e. if the decimal to be rounded is 5, it always rounds up to the next number. This is the standard method of rounding most people expect in most situations.  I also would like only significant digits to be displayed - i.e. there should not be any trailing zeroes.  I know one method of doing this is to use the String.format method:  String.format("%.5g%n", 0.912385);   returns:  0.91239   which is great, however it always displays numbers with 5 decimal places even if they are not significant:   String.format("%.5g%n", 0.912300);   returns:  0.91230   Another method is to use the DecimalFormatter:  DecimalFormat df = new DecimalFormat("#.#####"); df.format(0.912385);   returns:  0.91238   However as you can see this uses half-even rounding. That is it will round down if the previous digit is even. What I'd like is this:  0.912385 -> 0.91239 0.912300 -> 0.9123   What is the best way to achieve this in Java?


When should the keyword 'this' be used within C# class definitions?    Is it standard to use the form "this.Method()" from within class? Or to just use "Method()"?  I have seen both, and usually go with the second choice, but I would like to learn more about this subject.

I was curious about how other people use the this keyword. I tend to use it in constructors, but I may also use it throughout the class in other methods. Some examples:  In a constructor:  public Light(Vector v) {     this.dir = new Vector(v); }   Elsewhere  public void SomeMethod() {     Vector vec = new Vector();     double d = (vec * vec) - (this.radius * this.radius); }


cont = "y";         while (cont == "y")         {             System.out.println("Enter money.");             money = input.nextInt();             TestMachine.insertMoney(money);              System.out.println("Enter more money? ('y' for yes, anything else for no.)");             cont = input.nextLine();         }          System.out.println("Enter how many tickets do you want.");   When I enter my code, at this part, this is what happens.  Enter money. 34 Enter more money? ('y' for yes, anything else for no.) Enter how many tickets do you want.   The code will break the while loop before It's recieved input from the user and even though the variable 'cont' appears to still be "y". Could someone help me by explaining why this happens? Thanks.  I've been told to use .equals() instead of == in my code. It now looks like this.          cont = "y";         while ("y".equals(cont))         {             System.out.println("Enter money.");             money = input.nextInt();             TestMachine.insertMoney(money);              System.out.println("Enter more money? ('y' for yes, anything else for no.)");             cont = input.nextLine();         }          System.out.println("Enter how many tickets you want.");   however when I run the code the same problem arises. It breaks the loop before waiting for an input from the user.  Enter money. 34 Enter more money? ('y' for yes, anything else for no.) Enter how many tickets do you want.

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


How do I know when to use lay and when to use lie, and what are the different forms of each verb? I'm always getting them confused.


i need help on this problem: how can i prove that the metric d(x,y)=|x-y|/(1+|x-y|) from (ℝ,d) satisfies the triangle inequality?  Greetings

Let $(X,d)$ be a metric space and for $x,y \in X$ define $$d_b(x,y) = \dfrac{d(x,y)}{1 + d(x,y)}$$ a) show that $d_b$ is a metric on $X$  Hint: consider the derivative of $f(t)$ = $\dfrac{t}{1+t}$  b) show that $ d$ and $ d_b $ are equivalent metrics. c) let $(X,d) $ be $(\mathbb{R}, |\cdot|)$ Show that there exists no $ M>0$ such that $ |x-y| $ $\leq$ $Md_b$ $(x,y)$ for all $ x,y$ $\in$ $\mathbb{R}$  I have calculated $f(t)$ and $f'(t)$ and from this I know $f(t)$ is an increasing function as $f'(t)$ is strictly positive. But I don't know where to go from here or how to do parts b) and c)


I think that whenever a post gets edited by someone other than the person who wrote it and when the edit changes a MathJax formula, then, no matter how small the change was technically, the author of the post should be warned that that editon took place. A small change in a mathematical formula can have huge consequences.

Your summary page shows "N Edits to your posts" for the selected time period but you really have to be looking for it.  Could we add edits to the notification feed? You could put the reason for the edit (entered--or not--when the editor changes it) and just a link to the post.


Is there a breakdown of SO user distribution? I would like to know how many users SO gets from different countries. This query is not supported in the JSON API unfortunately.

I wanted to know more about . Is there any way I could get more data for this? Are there any more maps or charts to further identify where users are coming from across the world? How could I go about generating my own maps or charts?  Note: The original statistics and images provided with this question in 2009 are available in the .


I’ve just started second year at the University of Bristol, of which one of my modules is Metric Spaces.  I looked up what it means for a set to be well defined and also saw that $X = \{\emptyset\}$ is considered non-empty.  Continuing with that though process I wondered if the set defined below,  Let $X = \{\emptyset, \{\emptyset, \{\emptyset, ... \}\}\}$  is well defined.  My questions are is $X$ countable, could you define a metric on it and does it have any interesting properties or applications.  EDIT: Within ZFC set theory, $X$ violates the axiom of foundation. However, I still am interested in knowing if the set above has ... replaced with strictly finite repetitions, is defined as a set.  And if so, can you not define the set such that it has n repetitions. Then, the set would be defined $\forall n\in\mathbb N$, exept in the case of infinity  Thanks

I am trying to understand   How can a set contain itself? Can you show example of set which is not a set of all sets and it contains itself.


I posted this question earlier, but as I don't know if a comment reply or edit will refresh this so people actually see, I'm going to post it again in hopes that someone knows what's going on. Here's the initial question:  Replacing the sequence:  $x_{n}=1+\frac{1}{\sqrt{2}}+...+\frac{1}{\sqrt{n}}-2\sqrt{n},\,\,\,\, n=1,2,....$  By the corresponding series, invesigate it's convergence.  Hint: Take $a_{1}=x_{1}$ and $a_{n}=x_{n}-x_{n-1}$ for $n>1$. Then $x_{n}$ is a sequence of partial sums for $\sum_{k=1}^{\infty}a_{k}$. Use an expicit formula for $a_{n}$ and use the comparison in limit test to show that the series converges.  Solution: Computing $x_n - x_{n-1}$, we get:  $x_{n}-x_{n-1} = \left(\sum_{k=1}^{n}\frac{1}{\sqrt{k}}-2\sqrt{n}\right)-\left(\sum_{k=1}^{n-1}\frac{1}{\sqrt{k}}-2\sqrt{n-1}\right)$  $a_{n} = \left(\sum_{k=1}^{n-1}\frac{1}{\sqrt{k}}+\frac{1}{\sqrt{n}}-2\sqrt{n}\right)-\left(\sum_{k=1}^{n-1}\frac{1}{\sqrt{k}}-2\sqrt{n-1}\right)$  $a_{n} = \frac{1}{\sqrt{n}}-2\sqrt{n}+2\sqrt{n-1}$  Now, the comparison test states that:  If $\lim_{n \to \infty} \frac{a_n}{b_n} = c$ for some limit $c$, then either both $a_n$ and $b_n$ converge or diverge. Trick is, I'm really struggling to find a series $b_n$ that lets me show that $a_n$ diverges (i.e. that my fraction has a finite limit, hence $a_n$ diverges).

Actually not sure how to approach this... but I may be missing something:  Replacing the sequence:  $x_{n}=1+\frac{1}{\sqrt{2}}+...+\frac{1}{\sqrt{n}}-2\sqrt{n},\,\,\,\, n=1,2,....$  By the corresponding series, invesigate it's convergence.  Hint: Take $a_{1}=x_{1}$ and $a_{n}=x_{n}-x_{n-1}$ for $n>1$. Then $x_{n}$ is a sequence of partial sums for $\sum_{k=1}^{\infty}a_{k}$. Use an expicit formula for $a_{n}$ and use the comparison in limit test to show that the series converges.  Note: This looks easy, but as I said... there's something not quite connecting. When writing out the summation, I'm not entirely sure if they're compatible, as one would go from k=1 to n, and the other would go from k=1 to n-1, yet still vary with k... so do I need to use another pronumeral for it? Or can I simply use k-1 instead of k?


I wish to upgrade my current Ubuntu 13.04 to 13.10. While upgrading via software updater, it popped up a window with information that "Ubuntu 13.10 is beta".   So, may I know when it would be beta-free? As it's beta, so can it be reckoned stable or once it's free of beta then only it's stable? Is it preferred or advantageous to not upgrade my system now and put off until it's beta-free?

I want to know where I can find updated information about all the stable and in-development versions of Ubuntu, where I can find this information?     This question is meant to be a canonical question. It expects to answer the following questions:         Is X version stable yet?   Is X version in beta?   Is X version still supported?   What versions are still supported?   What are the versions in Beta/Alpha?   Until where X version will be supported?   Have X version ceased support?   When will be X version released?   Where I can download any release?   When will the next LTS version of Ubuntu be released?         The list is not exhaustive.


I want to show $\sqrt{x}$ is uniformly continuous on $[0, \infty)$. I know it is uniformly continuous on $[0,1]$ and I can show it's uniformly cts. on $[1, \infty)$, so if I choose $x=1/2$ and $y\in [1,\infty)$, is it uniformly continuous on $[0,\infty)$?

Prove that the function $\sqrt x$ is uniformly continuous on $\{x\in \mathbb{R} | x \ge 0\}$.  To show uniformly continuity I must show for a given $\epsilon > 0$ there exists a $\delta>0$ such that for all $x_1, x_2 \in \mathbb{R}$ we have $|x_1 - x_2| < \delta$ implies that $|f(x_1) - f(x_2)|< \epsilon.$  What I did was $\left|\sqrt x - \sqrt x_0\right| = \left|\frac{(\sqrt x - \sqrt x_0)(\sqrt x + \sqrt x_0)}{(\sqrt x + \sqrt x_0)}\right| = \left|\frac{x - x_0}{\sqrt x + \sqrt x_0}\right| < \frac{\delta}{\sqrt x + \sqrt x_0}$   but I found some proof online that made $\delta = \epsilon^2$ where I don't understand how they got? So, in order for $\delta =\epsilon^2$ then $\sqrt x + \sqrt x_0$ must $\le$ $\epsilon$ then $\frac{\delta}{\sqrt x + \sqrt x_0} \le \frac{\delta}{\epsilon} = \epsilon$. But then why would $\epsilon \le \sqrt x + \sqrt x_0? $ Ah, I think I understand it now just by typing this out and from an earlier hint by Michael Hardy .


I want to write a shell script where i change directory and then execute a command inside that directory. How come i cannot change directory? It does not work whenever i do:  #!/bin/bash  cd /something/something   What am i doing wrong? /Daniel

I'm trying to write a small script to change the current directory to my project directory:  #!/bin/bash cd /home/tree/projects/java   I saved this file as proj, added execute permission with chmod, and copied it to /usr/bin. When I call it by: proj, it does nothing. What am I doing wrong?


Kreacher is the house-elf of Grimmauld Place. From the death of the last black inhabitants, he was left alone until Sirius moved in. Then his ownership passed on to Harry.  Harry had him work at Hogwarts until DH when he had him back to Grimmauld Place. Some trust started to build between them, but after the Ministry of Magic chaotic escape, the house became accessible to Death Eathers (or at least presumably). Harry even thought about Kreacher for some time, and how he would be saddened by their disappearance and the invasion of the Death Eaters.  Nevertheless, we never get to know what happens to him afterward, IIRC. Is there any information about him after Harry, Ron and Hermione broke into the Ministry of Magic?

In  Deathly Hallows, when Harry, Ron, and Hermione are at No. 12, Grimmauld Place, Harry summons Kreacher from the kitchens at Hogwarts where the elf has been working on Harry’s orders given a year previously.  When the trio’s heist in the Ministry of Magic ends with Hermione inadvertently bringing Yaxley inside the perimeter of the Fidelius charm that protects Grimmauld Place, the trio leg it and dare not return there for fear that it’s now crawling with Death Eaters.  Before they leave for the Ministry in the morning, Kreacher is talking about making a stew or pot roast or something for dinner. After the trio go on the run and camp out in the tent, Harry thinks of poor Kreacher preparing a dinner they’ll never return to eat, but they dare not summon him lest a Death Eater tag along (like how Dobby ‘tagged along’ with Kreacher when Harry called him to have him follow Draco in Half-Blood Prince).  The next time we see Kreacher is during the Battle of Hogwarts where he leads the house-elves from the kitchen with battle-cries of “For Master! For Harry Potter!” (or something like that), so he’s clearly lost none of his new-found loyalty to Harry.  Harry is still Kreacher’s master throughout the book, and since he does not communicate at all with Kreacher after their escape from the doorstep, he cannot have ordered Kreacher to return to Hogwarts to work there again.  We know that house-elves can go against their masters’ wishes, but this usually entails them punishing themselves rather brutally, and Kreacher does not seem to have been constantly injuring himself for the better part of a year at Hogwarts.  So when and how does Kreacher leave his master’s house without orders and return to Hogwarts?


Could somebody correct this statement to stop sql injection, I have read through lots of answers but don't understand how to do it.   $conn = new mysqli($servername, $username, $password,   $dbname);  if ($conn->connect_error) {  die("Connection failed: " . $conn->connect_error);  }    $sql = "UPDATE daydxx SET $T1 ='$Dsc', $T2 = '$SV'  WHERE date = '$Dt' AND   $T1 = '' OR date = '$Dt' AND $T1 IS NULL ";   if ($conn->query($sql) === TRUE) {  etc etc

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


I am new to expect scripting, I have a case where I need to run a script on a on a server that contains our backups that will send a command to my firewall device that will send a backup to an internal FTP server. My snippet is  #!/usr/bin/expect set PASS="password" spawn ssh admin@10.3.0.1 -p 4118   #Firewall Device IP expect "Password:"  send "$PASS\r"   For some reason when running this small snippet of code by itself it still asks for a password to be entered.  I applied the changes suggested by Joao Vitorino, it' no longer asking for a password but it is throwing these errors:     TEST.sh: spawn: not found    TEST.sh: expect: not found    TEST.sh: send: not found

How can I use expect to send a password to an ssh connection.  say the password was p@ssword and the ssh command was ssh me@127.0.0.1  What would I do with expect to a make it input the password when it says  me@127.0.0.1's password: ?  The proper action of using an SSH key pair isn't an option because I would have to use ssh (scp) to put the key on the server, which would ask for a password.


I noticed that my vi editor changes inodes when editing files, except when that file is under /tmp. Why is this?

When I edit a file in "vi" editor the inode value of the file is changing. But when edited with cat command the inode value is not changing.


It's not entirely obvious to me that the group of permutations of a set A under permutation multiplication / function composition has $n!$ functions in it. Would someone be able to provide an intuitive explanation?   I am taking an undergraduate course on abstract algebra at the moment.

I have been working on this exercise for a while now. It's in B.L. van der Waerden's Algebra (Volume I), page $19$. The exercise is as follows:     The order of the symmetric group $S_n$ is $n!=\prod_{1}^{n}\nu$. (Mathematical induction on $n$.)   I don't comprehend how we can logically use induction here. It seems that the first step would be proving $S_1$ has $1!=1$ elements. This is simply justified: There is only one permutation of $1$, the permutation of $1$ to itself.  The next step would be assuming that $S_n$ has order $n!$. Now here is where I get stuck. How do I use this to show that $S_{n+1}$ has order $(n+1)!$?  Here is my attempt: I am thinking this is because all $n!$ permutations of $S_n$ now have a new element to permutate. For example, if we take one single permutation $$ p(1,\dots,n) = \begin{pmatrix} 1 & 2 & 3 & \dots & n\\ 1 & 2 & 3 & \dots & n \end{pmatrix} $$ We now have $n$ modifications of this single permutation by adding the symbol $(n+1)$:  \begin{align} p(1,2,\dots,n,(n+1))&= \begin{pmatrix} 1 & 2 & \dots & n & (n+1)\\ 1 & 2 & \dots & n & (n+1) \end{pmatrix}\\ p(2,1,\dots,n,(n+1))&= \begin{pmatrix} 1 & 2 & \dots & n & (n+1)\\ 2 & 1 & \dots & n & (n+1) \end{pmatrix}\\ \vdots\\ p(n,2,\dots,1,(n+1))&= \begin{pmatrix} 1 & 2 & \dots & n & (n+1)\\ n & 2 & \dots & 1 & (n+1) \end{pmatrix}\\ p((n+1),2,\dots,n,1)&= \begin{pmatrix} 1 & 2 & \dots & n & (n+1)\\ (n+1) & 2 & \dots & n & 1 \end{pmatrix} \end{align}  There are actually $(n+1)$ permutations of that specific form, but we take $p(1,\dots,n)=p(1,\dots,n,(n+1))$ in order to illustrate and prove our original statement. We can make this general equality for all $n!$ permutations: $p(x_1,x_2,\dots,x_n)=p(x_1,x_2,\dots,x_n,x_{n+1})$ where $x_i$ is any symbol of our finite set of $n$ symbols and $x_{n+1}$ is strictly defined as the symbol $(n+1)$.  We can repeat this process for all $n!$ permutations in $S_n$. This gives us $n!n$ permutations. Then, adding in the original $n!$ permutations, we have $n!n+n!=(n+1)n!=(n+1)!$. Consequently, $S_n$ has order $n!$.  How is my reasoning here? Furthermore, is there a more elegant argument? I do not really see my argument here as incorrect, it just seems to lack elegance. My reasoning may well be very incorrect, however. If so, please point it out to me.


Is it possible to grep the buffer?  For instance if I execute a build process in my VxWorks shell, linux shell, etc, is there a rolling file that contains buffer (e.g. data while scrolling)/previous output?

Is there any way to search the scrollback buffer in Terminator? I'd like to be able to search in the logs that are displayed when something is run from the terminal.


I have a model of a skeleton and a full armature but when it parents to the mesh with automatic weights , it says "Bone Heat Weighting: failed to find solution for one or more bones".

Here is the .  Picture:   It's nothing special but I cant figure out why I get problems rigging this mesh. It would be important and a great Help! Thanks for reading and I know there are a lot of guides answering this question but I tried all and it doesn't seem to work.


I'm confused on how to go in both directions and how to start this proof.

Let $R$ be a commutative ring with identity. Show that $R$ is a field if and only if the only ideals of $R$ are $R$ itself and the zero ideal $(0)$.  I can't figure out where to start other that I need to prove some biconditional statement. Any help?


I've just installed Ubuntu 16.04 LTS on a laptop. This laptop had previously w7. It's a dv6 pavilion, with dedicated radeon graphics card and integrated Intel graphics.  As far as I know, this laptop is 6 years old, and the only problem it had, was that the dedicated graphics don't work anymore. Basically if you install the drivers of this dedicated graphics, it gets blue screens and doesn't work. So since I found it out, I used it with Intel graphics, and no problem.  I put Ubuntu on it, and I just updated files. As soon as I tried to restart, it got completely frozen. Turning off and on the laptop again, every time I try to reboot it, it does the same thing.  SSD 250GB, completely formatted, just with Ubuntu 16.04 LTS on it.  Do you think the OS is trying to communicate with the dedicated graphics and gets frozen? How can I fix this?  Thanks.

I get the below errors when I start the system.  Now I am using the recovery mode, what should I do?  *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!! *ERROR* UVD not responding, trying to reset the VCPU!!!


I am trying to solve a simple problem using C++. The problem statement is this :  N triangles are given. And Each triangle is identified by the coordinates of its three corners in the 2-D cartesian plane. The job is to figure out how many of the given triangles are right triangles. A right triangle is a triangle in which one angle is a 90 degree angle. The vertices of the triangles have integer coordinates and all the triangles given are valid( three points aren't colinear ).    Input : The first line of the input contains an integer N denoting the number of triangles. Each of the following N lines contain six space separated integers x1 y1 x2 y2 x3 y3 where (x1, y1), (x2, y2) and (x3, y3) are the vertices of a triangle.  Output : Output one integer, the number of right triangles among the given triangles.  My C++ Program is this :   #include<bits/stdc++.h> using namespace std; int main() {     int n;     cin>>n;      cout<<"\n";      int ans = 0;     for(int i=0;i<n;i++)     {         int x1,y1,x2,y2,x3,y3;         cin>>x1>>y1>>x2>>y2>>x3>>y3;          double side1 = (double)sqrt( ( (x1-x2) * (x1-x2) ) + ( (y1-y2) * (y1-y2) ) );         double side2 = (double)sqrt( ( (x2-x3) * (x2-x3) ) + ( (y2-y3) * (y2-y3) ) );         double side3 = (double)sqrt( ( (x1-x3) * (x1-x3) ) + ( (y1-y3) * (y1-y3) ) );          double A = side1 * side1;         double B = side2 * side2;         double C = side3 * side3;          cout<<"A = "<<A<<"  B = "<<B<<"  C = "<<C<<"\n";          cout<<"A+B = "<<A+B<<" , ";         cout<<"B+C = "<<B+C<<" , ";         cout<<"A+C = "<<A+C;          cout<<"\n";          if( (A + B) == C )         {             ans++;             cout<<"first\n";         }         else if( (B + C) == A )         {             ans++;             cout<<"second\n";         }         else if( (A + C) == B )         {             ans++;             cout<<"third\n";         }          cout<<"\n\n";     }      cout<<"ans = "<<ans;  }   Output of above program is this :    But the Correct Output should be ans = 3 , because the first triangle and the last two triangles of the input example are right triangles.   I am not getting why my program is giving wrong output.

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


Q There are $t_n$ bounded sequence and $s_n$ tending to zero. Then, prove that $$\lim_{n\to\infty}s_nt_n=0$$ A  Since $t_n$ is bounded, There exists $M>0$ such that $$\left| t_n \right| \le M$$ for all $n$.  Since $\displaystyle\lim_{n\to\infty}s_n=0$, for any $\varepsilon_1\gt0$, there exists $N_1$ such that $$\left| s_n \right| \lt \varepsilon_1$$ for $n \ge N_1$.  In order to prove this proposition, it is enough to find $N_2$ satisfying that, for any $\varepsilon_2\gt0$, there exists $N_2$ such that $$\left| s_nt_n \right| \lt \varepsilon_2$$ for $n \ge N_2$  If $N_2=\text{_____}$, then $$\left| s_nt_n \right| \le \left| s_n \right| \cdot \left| t_n \right| \lt M \cdot \varepsilon_1 \le \text{_____} \le \varepsilon_2$$ for $n \ge N_2$    I proved until here. Can someone let me know what should be filled in the blank?

How can you prove that $(a_nb_n)$ is a null sequence given that $(a_n)$ is a null sequence that converges to zero and $(b_n)$ is bounded above by $A$?  The conditions of $(a_n)$ are: For every $\varepsilon > 0$ there exists an $N$ in Natural numbers such that $|a_n| < \varepsilon$ for all $n \ge N$.  The conditions of $(b_n)$ are: $b_n$ is a function natural numbers -> reals such that there exists $A$ with $|b_n| \le A$ for all $n$ in natural numbers.


While trying to install SQL server 2012, I get the error: "SQL server language media doesn't support the language of the OS"  I've downloaded the SQL server 2012 in English language only (2 times to make sure due to this silly feature/bug) and the Format dropdown in Control Panel Regional Settings is English only.  Attached is the error that I get:    I already followed this link:   My Windows Server 2012 is a fresh install. No DB has ever been installed. Please suggest what should I do? Should I download the whole 5 Gbs 3rd time or any better option? Thanks Microsoft!

I'm getting the following error when i try and install MSSQL 2008 on Windows Server Standard 2008 R2:


Currently, I use Circuitikz to draw my circuits for my LaTeX documents.  My issue is, it really takes a while to draw them and a GUI which would allow me to drag and drop the components would really be so much easier for this kind of thing.  Can anyone suggest to me suggest a GUI?  I also have other issues with Circuitikz that really make me want to find a better option...  Diodes are too big, I have to give coordinates to everything (so I can't really say, put R1 left of C1), and certain things are just a pain to do.  A GUI really would be so much better...  I've looked at XCircuit, but that also seems to have some issues and I failed at getting latex mode to work...

I found  to be a useful tool to help generate code for graphs. I suppose there must be other tools to help draw diagrams such as Sets/Venn Diagrams or Electrical Circuits (Logic Gates). Which ones would you suggest?


I'm looking to download a macOS-Catalina-10.15 but can't find it anywhere on the web nor the apple website. Could anyone help find a safe site, preferably apple to download? Thanks. I have a Macbook-Pro

Sometimes it's hard to search for older versions of macOS & OS X  on the App Store.  This is an attempt to provide the canonical QA for this issue, as per the Meta QA -  I expect it to be modified over time to hopefully become a complete information resource.  How can I get any older version of a Mac OS to be able to run as a VM, or to reinstall on my Mac?


My webhoster seems to have some troubles with DDOS attacks and routing overload. This makes my IP to be not available sometimes and I'd like to add a failover IP for the domain.  However, 2 A-Records means that it's similar to a load balancer which is NOT what i am looking for. I do not want the fallback machine to be accessed any time - except in case of real troubles or downtime of first choice IP.  Is there a out-of-the box solution that allows me such a failover ip?  If not, if it requires a DNS re-configuration: Is there a recommended script or similar that can be run on the secondary machine (of course, this is with a different hoster). This has to check whether the first choice ip is down and must overwrite the A-record, right? This requires my domain hoster to provide an API for the DNS settings...

This is a  about DoS and DDoS mitigation.   I found a massive traffic spike on a website that I host today; I am getting thousands of connections a second and I see I'm using all 100Mbps of my available bandwidth.  Nobody can access my site because all the requests time out, and I can't even log into the server because SSH times out too!  This has happened a couple times before, and each time it's lasted a couple hours and gone away on its own.  Occasionally, my website has another distinct but related problem: my server's load average (which is usually around .25) rockets up to 20 or more and nobody can access my site just the same as the other case.  It also goes away after a few hours.  Restarting my server doesn't help; what can I do to make my site accessible again, and what is happening?  Relatedly, I found once that for a day or two, every time I started my service, it got a connection from a particular IP address and then crashed.  As soon as I started it up again, this happened again and it crashed again.  How is that similar, and what can I do about it?


Could anyone give a specific example where the intersection of two principal ideals in an integral domain is not a principal ideal?

I am currently searching for an integral domain $R$ which allows lcm, but where the intersection of two principal ideals is not necessarily a principal ideal (or at least an example with two certain elements).   As converse example (where the sum of two ideals is not principal but $R$ allows gcd) is $\mathbb Z[X]$. It allows gcd, but obviously $\left<X+1,2\right>$ is not principal.  An example of an integral domain where the intersection of two principal ideals is not principal would be $\mathbb Z[\sqrt{-5}]$ with the ideal $\left<2\right> \cap \left<1+\sqrt{-5}\right>$, but this doesn't allow lcm.  Since I can't find a nice example, I put the question here. Maybe someone has already seen this? (I am not completely sure, one even exists, but pretty certain there is an example. In the case my hunch is wrong, I would be happy, if someone could proof me wrong.)


Correction on previous post.   I have a log linear regression model where the dependent variable is logged and an independent variable is linear. The slope coefficient for a key independent variable is negative: -.0564. Not sure how to interpret.  Do I use the absolute value of .0564 and then turn it into a negative like this: ((exp.(.0564)-1) * 100 = -5.80)  OR  Do I plug in the negative coefficient like this: ((exp.(-.0564)-1) * 100 = -5.48)  In other words, do I use the absolute figure and then turn that into a negative or do I plug in the negative coefficient? As you can see they produce 2 different answers.

I have a linear regression model where the dependent variable is logged and an independent variable is linear. The slope coefficient for a key independent variable is negative: $-.0564$. Not sure how to interpret.   Do I use the absolute value then turn it into a negative like this: $(\exp(0.0564)-1) \cdot 100 = 5.80$  or  Do I plug in the negative coefficient like this: $(\exp(-0.0564)-1) \cdot 100 = -5.48$  In other words, do I use the absolute figure and then turn that into a negative or do I plug in the negative coefficient? How would I phrase my findings in terms of a one-unit increase in X is associated with a __ percent decrease in Y? As you can see, these two formulas produce 2 different answers.


I want to hide some of the list from boot menu.Is it possible?

So basically I have a pretty flooded Grub bootloader, with older linux versions, 3 operating systems and memtests. What I want is to leave the operating systems only. I need to know how to do it manually, and I need someone to tell me what should I be aware of when a new kernel is released. Thanks in advance.


On a German keyboard layout I just need to press Alt Gr+m to get a 'µ' (micro) symbol.  How to do so on a English (US) keyboard?

The title pretty much says it all: how can I type Unicode characters - specifically the em-dash —?


I have two different accounts for Stack Exchange.  One account for  (entering E-Mail + password), and another for  via (also E-Mail + password, no Google or Facebook connection). I don't want the two connected for... reasons.  When I log into Stack Overflow, Science Fiction & Fantasy prompts me to connect my account to the site, instead of offering the option to use the other account.  Can I log in with two different accounts on different Stack Exchange sites at the same time, and if yes, how (with the same browser)?

There has been some recent behavior change on SE (around July 2015).  I have two accounts I use, one Google openId based for one set of sites (call it Account-A) and another SE login based for a different set of sites (Account-B).  Used to be that I could be logged into one set of sites with the first user and a different set with the other users.    But now I am logged in with the Account-A on Site-1.  When I go to one of the sites I use the other account for and click "log in" under the SE menu, I go to a page where I only have an option to confirm creation of an account based on my Google login.  It does not present a way to log in with an SE account.    How can I log in with my other account here?  (and before you flag this as a duplicate, please ensure the other question is recent enough and that the answer is relevant.  This behavior has definitely morphed over the years... and I am having trouble finding something that is relevant.  For instance this question  simply points out how to merge the accounts which is NOT what I want  .  This question  talks about presenting different user info on each site but that's not what I want -- I want totally separate accounts).


If someone's boggart was a Dementor, could they get Kissed and lose their soul?  Related:

If a boggart appeared to someone as a basilisk, would direct contact with its eyes kill that person?


I'm running Ubuntu 14.04 LTS and I would like to upgrade to Ubuntu 16.04 LTS.  When I launch the Software Updater, I am not prompted to upgrade to Ubuntu 16.04 LTS.  Anyway, settings for the Software Updater are correct.  Thanks for your help.

I'm following the , but on launching the upgrade tool I get this response:  Checking for a new ubuntu release No new release found   Am I doing something wrong? Is there a workaround?


Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


agree:  When you make an attack and succeed with a natural 20 (the number on the die is 20), or if the result of your attack exceeds the target's AC by 10, you achieve a critical success (also known as a critical hit).   disagrees:  If you rolled a 20 on the die (a “natural 20”), your result is one degree of success better than it would be by numbers alone. This means that a natural 20 usually results in a critical success and natural 1 usually results in a critical failure. However, if you were going up against a very high DC, you might get only a success with a natural 20, or even a failure if 20 plus your total modifier is 10 or more below the DC.  So if I roll a 20 on my third attack, but it is stil lower than the enemy AC (because of MAP for example), is it a critical hit, or a normal hit?

I was going over the degrees of success rules in relation to the above question and it's answers and came across a bit of rules that seem contradictory.  (Core Rulebook, General Rules, Checks p445)  You critically succeed at a check when a check’s result meets or exceeds the DC by 10 or more. If the check is an attack roll, this is sometimes called a critical hit. You can also critically fail a check. The rules for critical failure—sometimes called a fumble—are the same as those for a critical success, but in the other direction: if you fail a check by 10 or more, that’s a critical failure. If you rolled a 20 on the die (a “natural 20”), your result is one degree of success better than it would be by numbers alone.  We are, in general, pretty familiar of this concept introduced in the playtest era. However, there are more rules that seem like they may be more specific.  (Core Rulebook, Equipment, Weapons, Attack Rolls p278)  When you make an attack and roll a natural 20 (the number on the die is 20), or if the result of your attack exceeds the target’s AC by 10, you achieve a critical success (also known as a critical hit). If you critically succeed at a Strike, your attack deals double damage (page 451). Other attacks, such as spell attack rolls and some uses of the Athletics skill, describe the specific effects that occur when their outcomes are critical successes.  This second section makes no accounting for "would have been a success/hit", and says that "When you make an attack and roll a natural 20 [...] you achieve a critical success." Does this make attack an exception to the rules that natural 20's only take you one degree higher on success?


Accidentally updated to 9 version from 7. It lags a lot so I want to downgrade it at least to 8 version. Is it possible?  Via standart restore feature i get “This device isn’t eligible for the requested build”

I'm trying to downgrade my iPhone from the current iOS to an older one, as per .  But every time I try, I always receive this error:     The iPhone could not be restored. This device isn't eligible for the requested build.     I have tried many times with and without DFU mode. Any ideas regarding this?


This question always bothers me! Last time for 4.9 I tried the commands mentioned in . The same trick doesn't work now:  sudo add-apt-repository ppa:ubuntu-toolchain-r/test sudo apt-get update sudo apt-get install gcc-5.1 g++-5.1   results in...  E: Unable to locate package gcc-5.1 E: Couldn't find any package by regex 'gcc-5.1' E: Unable to locate package g++-5.1 E: Couldn't find any package by regex 'g++-5.1'   What is the correct command for directly installing the latest g++ in Ubuntu? Is there any magic command which works uniformly for all the updates of g++?  Update:  I found that the correct command to install it is:  sudo apt-get install g++-5   This works now! Though in the , the version is 5.1.

I want to compile my program with the latest version of gcc.  Ubuntu 14.04 comes with gcc 4.8.2, however there's 4.9.0 available, moreover, I see that it is available as a package: . I tried to install it  sudo apt-get install gcc-4.9   but it says  Reading package lists... Done Building dependency tree        Reading state information... Done Note, selecting 'gcc-4.9-base' for regex 'gcc-4.9' gcc-4.9-base is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.   Looks like it is already installed, just not as the default one? How do I utilize it to build my program?


Does anyone know how to calculate the distribution of $$X/(X+Y)$$ X  ~ G(p,a)  Y~G(p,b)  G is gamma distribution

Let IG denote Inverse-Gamma distribution   .   If $X\sim IG(\alpha,1)$ and $Y\sim IG(\beta,1)$. Show that   $\frac{X}{X+Y}\sim Beta(\alpha,\beta)$   I tried with jacobian transformation taking $Z=\frac{X}{X+Y}$ and $W=Y$ then $$X=\frac{WZ}{1-Z};Y=W$$  $$\frac{\partial(z,w)}{\partial(x,y)}=\frac{1}{(1-z)^2}$$  $$f_{z,w}(z,w)=f_x(\frac{wz}{1-z})f_y(w)(1-z)^2$$ $$f_{z,w}(z,w)=\frac{1}{\Gamma{(a)}}(\frac{wz}{1-z})^{-\alpha-1}e^{-\frac{(1-z)}{wz}}\frac{1}{\Gamma{(\beta)}}w^{-\beta-1}e^{-\frac{1}{w}}(1-z)^2$$  but I'm stuck, in some place I read that $\frac{X}{X+Y}$ is a type 3 Beta distribution, but I can't show that.


I just watch Star Trek IV and I noticed that Spock was talking to his mother. This baffled me greatly since when I watched the latest Star Trek movie (based on a very young Kirk and Spock) the planet he came from was destroyed, taking with it a very young mother of Spock.   Is there a reason for this or is it a movie mistake?

In the 2009 version of Star Trek, Nero and the Romulans come back through time via Blackhole and kill Kirk's dad and the original Star Trek timeline is altered  creating a whole new reality.  Why would Abrams not just stick to the timeline given by Roddenberry instead of altering it?


Let $R=R_1 \bigoplus R_2$ be the external direct sum of two rings $R_1$ and $R_2$ and let $G$ be an arbitrary group. Is the group ring $RG \cong R_1G \bigoplus R_2G $? Using this, can we extend it for $R=R_1 \bigoplus R_2 \bigoplus R_3$ ?   I have used the natural map and proved it is well defined. How to show it is a homomorphism and further it is one-one and onto?

I know for two groups $G, H$ (not necessarily finite) we have $R[G\times H]\cong (R[G])[H]$, but I was wondering if we had a similar statement for rings $R,\,S$. In other words, if $R,\,S$ are two (possibly noncommutative rings), is it true that $(R\times S)[G]\cong R[G]\times S[G]$?


Alright, I know it's within the rules to create a monster into a playable race. However the method to do so seems to be vague and not well explained. So while previously I asked if it was possible to convert monsters to PC was answered, it didn't answer how to do so in-depth.   If I were to use a CP 2 monster as an example like a Boar, how would this translate into a playable race?

I would like to create a new race which you can play as a PC without it being too overpowered for normal game settings. I would like one with wings, but are wings (even wings with clumsy maneuverability) (or gills or claws or a prehensile tail) potentially game-breaking? And what about racial traits and size categories and spell-like abilities-which ones are acceptable for PC use?


I currently have Nikon D3300 and love it - only use it in manual mode, etc, but I am quite limited with the size of the frame and just in general want to advance further in photography.  I have an opportunity to pickup a D700 that is quite used 250k+ shutter clicks on it, but still works great with no artifacts or any issues what so ever.  So the questions are:  1) D700 is much older than D3300, but is the sensor technology and larger size of sensor make D700 perform better in low light conditions assuming same lens? 2) Is there any reason one would prefer D3300 over D700?

What are the pros and cons of buying an older higher-level camera if the price is about the same as a new entry-level one?


I like to use both US and German keyboard layout but I find the process of switching between them via mouse tiresome. I want a keyboard-only solution.  Is there a predefined shortcut to change between multiple keyboard layouts, or if not, how could I define such a shortcut?

I have to change my language option very often. It is hard when I write something with combination of both "English" & "Bangla", because I have to change that option rapidly.  Is there any way to set a keyboard shortcut, so that I can change my language option by it while typing?  I am using MacBook Pro with OS X.   Here is a screen shot:    Screen Shot of my Preference:


I've installed the last update from yesterday and today I logged in and no terminal, no dash, launcher, nothing is working. I've tried the solutions from here:    and also tried this:  export DISPLAY=:0 ccsm   end enabled Unity and reboot from terminal but I still not working. When I log in guest session it's normal.  Is there a working solution for that? Thanks.

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


On my multimeter, near the 10 A connector it says 10 A MAX 10sec EACH 15min. I usually measure currents less than 1 A so I never cared about this.    Is it correct to assume that if the measured current is lower than 10 A, I can take the measurement in more than 10 sec and I don't have to wait 15 minutes?  I measured only a few times a current of about 4 A and I'm sure I didn't follow those time limits and the multimeter is still working (so far).  I read the manual, there's nothing written about this.

On my multimeter I have two current measurement connection. One for the mA and one for the A.  On the ampere one there's a time limitation but not on the mA one. Also they mention in the manual a kind of "cooldown time" after the measurement for the A one. So, basicaly, probing with this input can really slow down my project. (max 15 sec every 5 minutes)  My question is, I have to switch to that A one for a 600-700mA current (mA input is 500mA), as it's not a "big" current, can I bypass this limitation ? Is it design for higher current only or any measurement done on that input ? It's a middle-end multimeter but even the online datasheet is not complete about what. (Was excepting a kind of measured current/cooldown time graph)


I have a 500+ lines stored proccedure which I am writting and testing using the Microsoft SQL Management studio. Today I encounter the following 'strange' case. My query (in pseudocode) look like the following  create table #TempTable1 (Name varchar(30))  -- Some queries involving #TempTable1  drop table #TempTable1  -- Some queries  declare MyCursor cursor fast_forward for  select ......  open MyCursor  fetch next from MyCursor into @CursorValue while @@fetch_status = 0    begin         create table #TempTable1 (Name varchar(30))         -- Some queries involving #TempTable1         drop table #TempTable1          fetch next from MyCursor into @CursorValue      end  close MyCursor  deallocate MyCursor    My query fails with an error in the second create table     There is already an object named '#TempTable1' in the database.   I know that due to query optimizations the commands are not running in the sequence I am typing them. However this error still seems strange to me. I can put some go commands to force the execution, but this will create some other problems in my code e.g. I will have to redeclare some variables e.t.c. Renaming the tables will solve the problem but it will harm a little the readabillity of the code. So it is more 'curiocity' than an 'actual problem'.  Any suggestions on why this is happening and how I can avoid it?

I've got my code sort of segregated as "coherent blocks" that I can insert into a longer "configuration script" over and over, and one of the patterns I'm using is this:  CREATE TABLE #WidgetSetting  (     WidgetID bigint not null,     Name nvarchar(100) not null,     Value nvarchar(max) not null,     CreateDate datetime not null )  INSERT VALUES  MERGE TABLES  DROP TABLE #WidgetSetting   But now SSMS is complaining that the object already exists by the next time the CREATE TABLE fires. What gives?  I think it's obvious I'm going to have to declare the table once at the beginning of the script, truncate instead of drop, but it's frustrating, naturally, to not be able to just drop the table and use the same name again.


Back in 1992 my friend Richard recommended a fantasy trilogy with a young man called Gill as the main character. Modern day boy gets transported to another fantasy world etc.. The ending of the book where he triumphs over evil, results in the real world (his world, where he is an unknown hero ) having the text on the U.S. Dollar bill changing from "in God we Trust" to "in Gill we Trust". I borrowed the 2/3 books from the local library, however cannot recall the name.

I can't remember any names of characters or locations where the story took place but I do remember the basic plot of this early 90's novel; a human man inherits his father's house. In the basement there is a doorway to a fantastic land where adventure ensues. He fights elves and wins their deadly elf swords which he buries under concrete at the end of the novel (because if you don't get rid of them they will come back and get you).  At the end of the novel he must remake the world in his own imagination, turning the tough Elf King into a cobbler and making Jesse Jackson President. I have been looking high and low and have drawn a blank.  Any help would be appreciated. Thanks!


I am not able to change my default browser from Internet Explorer to Chrome because my company has internal tools which somehow break if my default browser is not IE. I work for a large company and the odds of being able to fix the functionality which breaks when I set Chrome as a default browser is approximately 0%. This is not an answer which will meet my needs.  I previously was able to view a list of all URLs and the default application which opens then and by changing web URLs to open in Chrome, I got 99% of this solution.   Since this, I have a new computer and these settings did not transfer appropriately.   However I cannot figure out how I was able to do this. I distinctly remember a list of all URLs and being able to set what application opens them.  Where can I view this list of hyperlinks and change applications accordingly?

How can I change or set the default application for handling a given file type? What about for some specified actions, like "open web browser" and "preview image"?


How were the colors for white balance chosen? Why is it specifically temperature going from blue to yellow and tint going from violet to green?

I have seen color temperature mentioned with regard to white balance, mixing different sources of light, etc., but I haven't come across a clear explanation of what it means to talk about the 'temperature' of light.  How does  the color temperature of my light sources effect the images I capture? Are some color temperatures inherently better than others?


I just visited  and noticed that my profile picture is not the same as on all other sites.  According to  the image will be synchronized when synchronizing the complete profile. I did that but the image is still the same.  Then I wanted to change the image in the Area51 profile directly - but I can only change to a gravatar image and can't use the new and fancy Stack Exchange image.  Is that a bug?

So I was playing around on Area 51 hoping for further news on the private beta for ebooks, and noticed that my avatar (a hand) was missing. Also the Area 51 has the old toolbar. So I looked at the flair page. The network flair has my hand, the Area 51 flair has a quilt. OK, so time to upload a new image, and WordPress -- WordPress -- I don't want to login to WordPress. Any idea what's up with that?  The following questions did not help, and have different causes and symptoms:


I have to show that $\mathbb{C}/\mathbb{Z}$ is isomorphic to the multiplicative group $\mathbb{C} \setminus \{0\}$.   Proof. Let $f:\mathbb{C} \setminus \{0\} \rightarrow \mathbb{C}/\mathbb{Z}$ be the map $$ f(\alpha) = \alpha \mathbb{Z}.$$ This map has inverse $f^{-1}(\alpha \mathbb{Z})  = \alpha$ so it is bijective. Furthermore, $$f(\alpha  \beta) = (\alpha \beta)\mathbb{Z} = \alpha \mathbb{Z} \beta \mathbb{Z} =f(\alpha) f(\beta)$$ and $f(1) = \mathbb{Z}$, so the map $f$ is also a homomorphism.  Question.  Is this correct? It feels a bit like I am cheating.

Is there a "nice" way to think about the quotient group $\mathbb{C} / \mathbb{Z}$?  Bonus points for $\mathbb{C}/2\mathbb{Z}$ (or even $\mathbb{C}/n\mathbb{Z}$ for $n$ an integer) and how it relates to $\mathbb{C} / \mathbb{Z}$.  By "nice" I mean something like:   $\mathbb{R}/\mathbb{Z}$ is isomorphic to the circle group via the exponential map $\theta \mapsto e^{i\theta}$, and $\mathbb{C}/\Lambda$ is a complex torus for $\Lambda$ an integer lattice (an integer lattice is a discrete subgroup of the form $\alpha\mathbb{Z} + \beta\mathbb{Z}$ where $\alpha,\beta$ are linearly independent over $\mathbb{R}$.)   Intuitively, it seems like it should be something like a circle or elliptic curve.


From running help . or help source     Execute commands from a file in the current shell.      Read and execute commands from FILENAME in the current shell.  The       entries in $PATH are used to find the directory containing FILENAME.   From my point of view, it seems like the dot command (or the source command) is simply running a shell script in the current shell context (instead of spawning another shell).  Question: why doesn't . (or source) requires the file to be executable like when you run a normal script?

With Bash's source it is possible to execute a script without an execution bit set. This is documented and expected behaviour, but isn't this against the use of an execution bit?  I know, that source doesn't create a subshell.


I want to have a figure with subfigures like this:    I tried to use \usepackage{subfig} but I get an error: ! Package subcaption Error: This package can't be used in cooperation(subcaption) with the subfig package.

Is it possible to achieve the following layout with the subfigure package (and any other package/command I don't know about):  ############# ############## #           # #            # #  pic1     # #            # #           # #      pic2  # #           # #            # ############# #            #               #            # ############# #            # #           # #            # #   pic3    # #            # #           # #            # #           # #            # ############# ##############    Each picture should have a subcaption.


There's a handy multiple-choice command case in bash which simplify the condition logic.  Suppose such a minial script:      read -p "Enter selection [0-2]: " num     if [[ $num =~ ^[0-2]$ ]]; then         if [[ $num == 0 ]]; then              echo "num eq 0"         fi         if [[ $num == 1 ]]; then              echo "num eq 1"         fi          if [[ $num == 2 ]]; then              echo "num eq 1"          fi      else         echo "Invalid Entry." >&2         exit 1     fi   It could be refactored as      read -p "Enter selection [0-2]: " num     case $num in          0)  echo "num eq 0" ;;         1)  echo "num eq 1" ;;         2)  echo "num eq 2" ;;         *)  echo "Invalid Entry." >&2             exit 1 ;;      esac         Python does not include multiple options builtins as case      num=int(input( "Enter selection [0-2]: "))     if num == 0:         print( "num eq 0")     elif num == 1:         print( "num eq 1")     elif num == 2:         print( "num eq 2")     else:         print( "Invalid Entry.")   How to achieve such a logic in a case-like way with python?

I want to write a function in Python that returns different fixed values based on the value of an input index.    In other languages I would use a switch or case statement, but Python does not appear to have a switch statement.  What are the recommended Python solutions in this scenario?


I am using Drush to update modules. When I run the command php -v it correctly shows I am running version 5.5  I then use the command drush rf followed by drush up to perform any updates.  I am using the Schema.org Metatag module which requires php version 5. The website is running php version 5.5.37  The default CLI version on Hostgator shared server is 5.4.45. That is what I was originally using for drush. When I received the message below I found the path to use php 5.5 but I am still getting the same message. So I can't figure out how it still sees php ver 5.4.45 and how to resolve this so it doesn't keep disabling that module.  When Drush runs an update I get the following message: Schema.org Metatag requires at least PHP 5.5. (Currently using PHP   [warning] 5.4.45)  And then it disables the Schema Metatag module.  NOTE: When I run command drush status: PHP configuration: opt/php55/lib/php.ini Drush version is 8.1.11  Thanks  Extra information  .bash_profile  PATH=$PATH:$HOME/bin  export PATH  alias composer="/opt/php55/bin/php ~/bin/composer.phar"  alias drush="/opt/php55/bin/php ~/.composer/vendor/bin/drush.php"    .bashrc   alias php='/opt/php55/bin/php'   alias composer='/opt/php55/bin/php ~/bin/composer'  export DRUSH_PHP='/opt/php55/bin/php'     php -v returns PHP 5.5.37  which php doesn't return anything  drush status returns PHP configuration /opt/php55/lib/php.ini    But, when I use Drush to update a module I still get: Schema.org Metatag requires at least PHP 5.5. (Currently using PHP [warning] 5.4.45)

I'm running Drush on a host that has multiple versions of PHP installed. By default, php --version would give you 5.2.x, but php53 and php54 are also available. So in my .bash_profile I have alias php='php53' (php --version = 5.3.13), which makes Drush work for some commands.  However, I still get "Your command line PHP installation is too old. Drush requires at least PHP 5.3.2" messages for some very useful commands.  A couple of really annoying instances:   drush pm-update will report that it has backed up and then updated all modules and core successfully, then return the PHP version error and restore all backups. In verbose mode, the command that comes before the error is: php /home/[username]/drush/drush.php  --backend=2 --verbose --root=/home/[username]/webapps/drup --uri=http://[domain name]  pm-updatecode-postupdate 2>&1 drush archive-dump will immediately return the PHP version error   The other commands I have tried so far work fine. I'm not sure why this would be, if Drush is sometimes using the php53 binary, and other times not, or if it just has trouble detecting the version correctly, but some very important features are broken for me.


There's not much more to the question: If $f(x) \in \mathbb{Z}[x]$ is an irreducible polynomial, is there a simple proof that there must be some $x$ for which $f(x)$ is a prime number (positive or negative, e.g. $f(x)=-13$ is OK here)?  By irreducible I mean to imply that $f(x)$ is not $0$ or a unit of $\mathbb{Z}[x],$ as some texts demand of an irreducible element. But to simplify things, just assume $f$ has degree at least $1$ [the degree 0 irreducibles being integer primes anyway, which do represent at least one prime].  UPDATE: Note that an example of Hurkyl's gives an irreducible $f$ not representing any primes. $f(x)=x^2+x+4.$ This was pointed out by Lucien in a comment, and that comment has a link to the question with Hurkyl's polynomial in an answer.

Suppose $f(x)$ is an irreducible polynomial over $\mathbb Z$ of degree $n$. Is it always the case that there exist distinct $x_1,\ldots,x_{2n+1}\in \mathbb Z$ such that $f(x_1),\ldots,f(x_{2n+1})$ are all prime?  So far I've tested a few irreducible polynomials using mathematica, and this has held. The motivation is to use this as a test for irreducibility, as if $f(x)$ is not irreducible then it takes on at most $2n$ prime values, as either factor takes on $1$ or $-1$ at most $2n$ times. (I'd also be interested in learning if this bound can be improved).  This could potentially be expended to other rings of integers, i.e. $\mathbb Z[i]$, but in that case the minimal number of primes needed to certify that $f(x)$ is irreducible would increase as more units appear.


I've seen the other posts on this question, but unfortunately I'm still having difficulty understanding the meaning of the direction of the torque vector.  It makes intuitive sense that the magnitude of the torque exerted on an object is dependent on the length of the lever arm and the angle between the lever arm and the applied force.    What I don't understand is what the direction of the torque vector is describing. How can I relate the direction of the torque vector to a real world example (that is not an example involving a wrench + screw and the screw "unscrewing" in the direction of the torque...which doesn't give me any more of an intuition on what torque means).  Thanks!

I apologize if this question is dumb, but I've looked all over for a straightforward answer, and either I can't find one or either the terms are too complex for me to understand. I have only a rudimentary knowledge of Mechanics, but I do understand basic Linear Algebra. So torque, mathematically, is the cross product of the radial distance vector and a force vector. This cross-product gives another vector that is orthogonal to both vectors and it points either outside or towards the "page" (in the context of a two-dimensional diagram). Assuming this is correct, I do not understand what it pointing in or out means. Does it even have a physical, intuitive meaning? The best answer I've been able to come up with is that it's just a mathematical convention with no actual physical meaning, meant to provide a framework within which operations between torque vectors, such as addition and subtraction, make sense. Am I correct or way off the mark here?


Question: Given three IID random variables $X,Y,Z$ uniformly distributed on $[0,1].$ Calculate $\mathbb{P}(X+Y>Z).$   My attempt:  Let $f_{XYZ}$ be the joint density function of $X,Y,Z.$ by IID, $f_{XYZ} = f_X\cdot f_Y \cdot f_Z = 1$ where $f_X,f_Y,f_Z$ are probability density function of $X,Y,Z$ respectively. It follows that  $$\begin{align*} \mathbb{P}(X+Y>Z) & = \mathbb{E}[ 1_{\{X+Y>Z \}} ] \\ & = \int_{-\infty}^\infty \int_{-\infty}^\infty \int_{-\infty}^\infty 1_{\{X+Y>Z \}}(x,y,z) f_{XYZ}(x,y,z) dzdxdy \\ & = \int_0^1 \int_0^1 \int_0^{x+y} dzdxdy \\ & = \int_0^1 \int_0^1 (x+y) dxdy \\ & = \int_0^1 0.5 + y dy \\ & = 0.5 + 0.5 \\ & = 1 \end{align*}.$$ However, suggested answer is $\frac{5}{6}.$ I am not sure where is my mistake.

I'm trying to follow a line in a derivation for $P(Z>X+Y)$ where $X,Y,Z$ are independent continuous random variables distributed uniformly on $(0,1)$.  I've already derived the pdf of $X+Y$ using the convolution theorem, but there's a line in the answer that says:  $P(Z>X+Y) = \mathbb{E}[\ P(Z>X+Y\ |\  X+Y )\  ]$ where $\mathbb{E}$ is the expectation.  I'm not familiar with this result. Could anyone give a pointer to a similar result if one exists?  Thanks.


How to throttle CPU on a Mac?  I want to throttle CPU so that I can extend the battery life on a single charge.  Device: MBP 2015. Running Majove.

When there is less than 5% battery left on a mac, the battery indicator goes red and system performance significantly drops - presumably in an attempt to make that remaining 5% last a little longer.   Is there a way to manually trigger this, so that the system performance is low (and battery life longer), even when there is plentiful battery?   This would theoretically be a way of extending the number of hours on a battery beyond the rated amount.


I have a video file of 30 minutes, but I want to extract a video from 00:09:23 to 00:25:33.   I can define the startposition with -ss, but I couldn't find one for the end position. Any help please?

I am using ffmpeg to cut out a section of a large file like this: ffmpeg -i input.wmv -ss 60 -t 60 -acodec copy -vcodec copy output.wmv  The -ss part works fine but the -t is ignored. It correctly removes the initial specified seconds specified with -ss but then keeps going to the end of the input with the copy. Is there a way to use ffmpeg to cut off the end of a video without recoding it?


Define $(X_n)$ to be a bounded sequence of real numbers such that $∀n∈ℕ, X_n ≥ 0$  Show that $\liminf \sqrt{X_n} = \sqrt{\liminf X_n}$  Side-question: $(X_n) ⊆ ℝ$?  How should I go about on this proof? I don't see a direct way and am wondering if I should first prove $\liminf \sqrt{X_n} \le \sqrt{\liminf X_n}$ and then $\liminf \sqrt{X_n} \ge \sqrt{\liminf X_n}$?  How do I start? If I consider $u ∈ S(\sqrt{X_n})$, a subsequence limit of $\sqrt{X_n}$, how to proceed?

Let $(x_n)$ be a bounded sequence of real numbers such that $x_n \ge0$ for each $n \in \mathbb N$. Show that $\liminf(\sqrt{x_n})=\sqrt{\liminf x_n}$.   I assume we need to consider the subsequence of ($\sqrt{x_n}$), but I'm really confused with the  notion on "boundedness". Can I assume the question implies an upper bound on $(x_n)$?  Even then wouldn't the equation be implied? Given how roots generally affect limits.


Whenever I try to download any app from the Google Play store, an error pops up, giving the message "Retrieving information from server. ". This error does not go away, however I try. How do I go about fixing this ?

It used to work fine but now when I open the Play Store app it says "Error retrieving information from server. [RH-01]" and I can't do anything. I tried clearing the cache of the Google Play Store and Google Play Services but it still has the problem. Gmail still works from the phone so I don't think it's a problem connecting to my google account.  I have an Xperia Arc with custom rom, which turns out to be the problem. See accepted answer.


I cannot find the answer to my particular case at the forums. I had successfully installed ubuntu 16.04 with dual boot windows 10. But, the problem is I cannot boot into ubuntu, at least not in a normal way.  I can boot ubuntu from recovery mode (advanced option from grab menu), but every time I tried to boot it normally, I got stuck sometimes on a black screen. Sometimes, (after several reboots), I got to the ubuntu logo with progress dots, but I got stuck there again.   One time I was successfully able to boot normally, I don't know why or how (I had been trying every solutions I can find over this problem), but after restart, I got stuck on the black screen again.  Sometimes, some lines of code appear on the left top corner of the screen, and I got stuck there. No matter what I tried, I just cannot boot normally.  Please help. (I am a newb and this is my very first attempt to install ubuntu, the only OS I am familiar is windows)

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


In the sentence:     I suspect 99% of the world’s population has never even heard of the term ‘Deep Learning’.   is the 'has' correct, or should it be 'have'?

Does a percentage require a singular or plural verb, for example, do we say ten percent "go" or "goes"?


In  it states that humans (the race that originated from Coruscant) were favored over alien species. The Rebellion and later on The  Resistance seems to use more aliens , particularly in the upper ranks.     Many humans changed the course of history, from politicians to a mere slave boy turned Jedi Knight.Sheev Palpatine, who founded the autocratic Galactic Empire that ruled over the galaxy for two decades, was a human from Naboo. Many members of the Alliance to Restore the Republic's leading circle, including Mon Mothma, Bail Organa, and his adopted daughter Leia Organa were humans as well. The Galactic Empire was known to favor humans at the expense of alien species. The Empire's government and Imperial Military was dominated by humans.   And the  from Wookieepedia.     Enlistment was open to human men and women, who were trained at the   numerous Imperial Academy complexes across the galaxy, with many   members becoming enlisted personnel, officers or Stormtroopers.   Since the Empire favored humans and looked down on Aliens, it was rare   to find non-humans serving in the Imperial Military   Is their anything canonical that states why there usage was prefered?

Throughout the , we exclusively see human Empire officers, while the rebels’ staff seems to be composed from a large range of species. While a non-human rebel officer is only shown in the  (specifically ), I don't remember any non-human Empire officer. There is the notable exception of , but if I remember from the  (I read those about 15 years ago), it was stated that this was something unusual. There is also , who was not human, but it was before the Emperor's rise to power. Although "racist" is probably not the correct word, as it's the human versus non-humans species, was the Empire, and so the Emperor, racist?


Hi I'm trying to make a simple code to run my function in async way. But the result turn out to be quite unexpected. the result i want is like the counter function can run in parallel way and output the result some way similar like: Start1 End1 Start2 End2 Start3 Start4 End 3 ...... Hi but it turns out it only get the for loop value i=60 into counter function. I'm quite new to async method and google also cant find the appropriate explanation. namespace Asycn {    class Program    {        static async Task Main(string[] args)        {            var tasks = new List<Task>();            for (int i = 0; i < 60; i++)            {                tasks.Add(Task.Run(()=>counters(i)));            }             await Task.WhenAll(tasks);            Console.WriteLine("Hi");         }         private static void counters(int num)        {            Console.WriteLine("Start"+num.ToString());            Thread.Sleep(num*1000);            Console.WriteLine("End"+num.ToString());        }    }  }  And below is the running result

I met an interesting issue about C#. I have code like below.  List<Func<int>> actions = new List<Func<int>>();  int variable = 0; while (variable < 5) {     actions.Add(() => variable * 2);     ++ variable; }  foreach (var act in actions) {     Console.WriteLine(act.Invoke()); }   I expect it to output 0, 2, 4, 6, 8. However, it actually outputs five 10s.  It seems that it is due to all actions referring to one captured variable. As a result, when they get invoked, they all have same output.  Is there a way to work round this limit to have each action instance have its own captured variable?


trying to install wordpress on osx mavericks (with built-in apache+php and homebrew mysql).  mysql -u root # connects php -r 'var_dump(mysql_connect("localhost", "root", ""));' # doesn't connect   web-searching revealed that mysql connects to 'localhost' via a unix socket, but connects to loopback ip 127.0.0.1 via a network socket.  php -r 'var_dump(mysql_connect("127.0.0.1", "root", ""));' # connects!   why can't i connect to mysql via localhost from php??

this is somewhat of a mystery to me. The only way I can connect to MySQL is if I call it via "127.0.0.1" ... for example, my PHP connect script will NOT work with localhost  I'm running Mac OS X Lion, built-in apache2, MySQL, PHP, phpMyAdmin  mysqladmin:  count                             0 debug-check                       FALSE debug-info                        TRUE force                             FALSE compress                          FALSE character-sets-dir                (No default value) default-character-set             auto host                              (No default value) no-beep                           FALSE port                              0 relative                          FALSE socket                            (No default value) sleep                             0 ssl                               FALSE ssl-ca                            (No default value) ssl-capath                        (No default value) ssl-cert                          (No default value) ssl-cipher                        (No default value) ssl-key                           (No default value) ssl-verify-server-cert            FALSE user                              (No default value) verbose                           FALSE vertical                          FALSE connect-timeout                   43200 shutdown-timeout                  3600 plugin-dir                        (No default value) default-auth                      (No default value)


I have:  list_nums = [1,18] list_chars = ['a','d']   I want:  list_num_chars = [{'num':1, 'char':'a'},                   {'num':18, 'char':'d'}]   Is there a more elegant solution than:  list_num_chars = [{'num':a, 'char':b} for a,b in zip(list_nums, list_chars)]

Imagine that you have the following list. keys = ['name', 'age', 'food'] values = ['Monty', 42, 'spam']  What is the simplest way to produce the following dictionary? a_dict = {'name': 'Monty', 'age': 42, 'food': 'spam'}


I am self studying principle component analysis using , I got most of the reasoning behind PCA but I don't get the intuitive reason why eigen vectors of a covariance matrix is also its largest principle component. # eigendecomposition of covariance matrix values, vectors = eig(V) print(vectors)

In today's pattern recognition class my professor talked about PCA, eigenvectors and eigenvalues.   I understood the mathematics of it. If I'm asked to find eigenvalues etc. I'll do it correctly like a machine. But I didn't understand it. I didn't get the purpose of it. I didn't get the feel of it.        I strongly believe in the following quote:     You do not really understand something unless you can explain it to your grandmother. -- Albert Einstein   Well, I can't explain these concepts to a layman or grandma.   Why PCA, eigenvectors & eigenvalues? What was the need for these concepts? How would you explain these to a layman?


Is there some real time scan antivirus software for ubuntu studio?  Where?  Well, I know the typical answer: "It is very hard to find a virus to Linux."  The problem is to all of those people (like me) that still have to use some Windows OS software.  This is because there aren't some Linux software to replace some Windows software (for example, my case about a radio automation package).  Greetings & Blessings from Chile!!!  Juan

What antivirus programs are available for Ubuntu?  We previously used Symantec Endpoint Protection but it does not work in Ubuntu.


If $a,b,c$ be distinct (non-zero) such that  $ a+ \frac{1}{b}= b+ \frac{1}{c}= c + \frac{1}{a} = k$  how do I find the value of k ?

If $a, b, c$ be distinct reals such that $$a + \frac1b = b + \frac1c = c + \frac1a$$ how do I find the value of $abc$?  The answer says $1$, but I am not sure how to derive it.


I have an issue with Java interface. How can I make a JTextfield that is left blank return an integer result, as a default? I have tried doing it like this:  if ( txtDescuentoCI.getText( ) == "" )         return 0;     else         return Integer.parseInt( txtDescuentoCI.getText( ) );   It won't work, though. Any ideas?

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


I am trying to fill the diagonal of an infinity matrix with 0.     num_vertices = 5     distance_matrix = num_vertices * [num_vertices * [float("inf")]]      print(distance_matrix)      for v in range(num_vertices):         distance_matrix[v][v] = 0      print(distance_matrix)  First print [[inf, inf, inf, inf, inf], [inf, inf, inf, inf, inf], [inf, inf, inf, inf, inf], [inf, inf, inf, inf, inf], [inf, inf, inf, inf, inf]]  Second print [[0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0]]  As you can see, even though I am setting only v, v from 0 to 5, it sets every value as 0. What is causing this to happen?

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


Are there some Latex editors that allow the online sharing? I mean an editor that when a shared file is opened by two users (for example using dropbox), each person can see on time what the other person is writing. I know that Sharelatex do it, but I would like to get an editor installed directly on my mac.

Are there any tools for simultaneous collaborative editing of a .tex file?  The practices I know (and practice) in writing scientific papers are:   e-mailing each new version to the collaborators, working in a same Dropbox folder.   However, both are not meant for simultaneous editing, and are somewhat annoying.  EDIT:  A list is also here:


string str1 = "hello";     const char* string1 = str1;    I get an error..     cannot convert ‘std::string {aka std::basic_string}’ to ‘const char*’ in initialization   how do i cast string to const char*  Thanks for helping

How can I convert an std::string to a char* or a const char*?


Checking index fragmentation in my database seems unruly slow. Regardless if I use the DMV sys.dm_db_index_physical_stats (for a specific database, table, or even index) or if I use the SSMS Index Properties window to look at Fragmentation on a specific index, it takes a really long time.   For example, using the Index Properties window will take upwards of 5 minutes to open up for a single index on my largest (~20 billion rows) table.  I do want to push to implement partitioning but until then I have to support an existing index maintenance job and I'm not sure how we can even check index fragmentation when one index on our heaviest table takes about 5 minutes to analyze. (Each of our tables has at least a few indexes.)  Here's a case where it took so long in the Index Properties window that I think it timed out and returned nothing in window:

I have been a DBA for 3 months now at my first job out of college and I am having a significant amount of difficulty trying to figure out how to accurately query and report on index fragmentation across 2 of our production servers (2 separate clusters, but that doesn't matter for this specific question... let's just pretend I have 1 server).  We use Ola Hallengren's scripts for index maintenance already, but I need to query all of our databases on our server and get the fragmentation % along with the table name, index name, and database name.  Here is my current query that doesn't seem to be correct:  SELECT s.[name] +'.'+t.[name]  AS table_name    ,i.NAME AS index_name    ,dbd.name AS [database_name]    ,index_type_desc    ,ROUND(avg_fragmentation_in_percent,2) AS avg_fragmentation_in_percent    ,page_count    FROM sys.dm_db_index_physical_stats(NULL, NULL, NULL, NULL, 'LIMITED') ips   INNER JOIN sys.tables t on t.[object_id] = ips.[object_id]   INNER JOIN sys.schemas s on t.[schema_id] = s.[schema_id]   INNER JOIN sys.indexes i ON (ips.object_id = i.object_id) AND (ips.index_id =   i.index_id)   INNER JOIN sys.databases AS dbd on dbd.database_id = ips.database_id   WHERE i.type IN (1,2) -- Include ONLY Clustered & Non-Clustered Indexes   AND s.name <> 'Audit' -- Exclude Audit Schemas   AND ips.page_count > 100 --Exclude small page counts   AND ips.alloc_unit_type_desc = 'IN_ROW_DATA'    AND ips.index_level = 0 -- Current level of the index. 0 for index leaf   levels... Greater than 0 for nonleaf index levels.   Even when I remove the WHERE clauses it still seems my data is incorrect.  One of my records/tuples shows a table in a database with an index that has 1700 pages, but when I manually go to that index it only has 1?  I have been working on this for hours and can't seem to figure out what is going on.  I have read all of the documentation for this DMV.


How could I make this sprinklish colourful dot material from this picture?    Source:

is it possible to create this kind of material with the standard textures? The Voronoi texture (set to cells) is coming close but I don’t know if it is possible to a) set the single cells apart from each other and b) to give them seperate colors.


I have a .txt file with 5 urls in it. I want to read it line by line, and perform 4 ping requests for each site, and extract the time. The code I wrote is below, but it isn't working.   Can anyone give me a hint?   #!/bin/bash  cat /home/akis/Desktop/sites.txt declare -i var=1 while read -r line do     while $var <= 5      do         var2=$((var2+1))          name="$line" | ping -c 4 $name > $var.txt | awk '{ print $8 }' < $var.txt | awk '/time/' > $var2.txt | tr '=' '\t' < $var2.txt | awk '{ print $2 }' > $var2.txt     done      var=$((var+1))   done

How can I execute four ping requests for each URL from a text file that includes URLs, calculate the average respond time and store the results in another text file?


I have 2 keyboards (input languages): English and Russian.  After every update requiring a restart, 2 Latvian input methods show up. So I have in total 4: EN, RU, 2 x LV.  If I go to settings, it only shows 2: EN and RU. So I can't remove LV from here.  What I tried:   If I manually add LV and remove it, I'm left with 3 layouts: EN, RU, LV.  The first time it happened,  helped. But now the DWORD is set, and keyboards still appear and stay after restarts. Tried changing Country / Display settings / Defualts & Overrides   The questions:   How do I remove the second LV keyboard? How do I prevent them from re-appearing?   OS: Windows 10 Pro, version 1607. Primary display language: EN.

I have a Spanish keyboard on my notebook, but I use it mostly for English and Chinese writing.  This is how I configured the languages:    However, Windows added some layouts on its own (probably when connecting via Remote Desktop to computers with different languages/layouts):    Those layouts are all part of the AltShift cycle, which is extremely annoying.  How can I remove ENG/US and ESP, considering they don't show in the configuration list?  Is there a way to prevent them from being added again?


$I_n$ is given by $$I_n=\int_1^a \dfrac{n \ dx}{1+x^n}, \qquad a>1.$$   Find $\lim\limits_{n\to\infty}I_n$.

I'm trying to find $$ \lim_{n \to \infty}   \int_1^a \dfrac{n}{1+x^n} \, dx  ,$$ where parameter $a>1$. The limit appears to be $\ln 2$ regardless of the value of $a$. Some trick is probably needed here, but i don't see it.


I am an Indian citizen. I plan to go to UK for an onsite job interview with an overnight stay and return back to India next day. I need an advice regarding  financial documents submission.    I am an unemployed person, but I have a job offer for which I can submit job offer letter.  I am aware about personal financial documents submission for which I can submit bank statements which shows that I have enough balance for a one day stay, but a trust in India is sponsoring my travel to UK for air and visa expenses. Is it OK to submit their letter of sponsorship with their registration number or will be my application be refused on this ground?

The UK Visas and Immigration Directorate publishes  that provides helpful tips that can result in successful visa applications. Section 2 of this guidance opens is entitled "other documents you may want to provide" (emphasis mine).  Section 2: other documents you may want to provide – all visitors This section provides guidance on the types of documents that you may want to provide to help us consider your application against the Immigration Rules. Previous travel documents/passports, which show previous travel. Financial documents showing that you have sufficient funds available.  These must clearly show that you have access to the funds, such as:  bank statements building society book proof of earnings such as a letter from employer confirming employment details (start date of employment, salary, role, company contact details) where a third party (who is either in the UK or will be legally in the UK at the time of your visit) is providing financial support to you e.g. a business, a friend or a relative, documents to show that they have sufficient resources to support you in addition to themselves and any dependant family should be provided   The first item is "bank statements" and this ties in with the , which says...  evidence that you can support yourself during your trip, eg bank statements or payslips from the last 6 months  (Note 'eg' is a Latin abbreviation meaning "for example"; this appears to be optional rather than a fixed requirement.) Question: How should someone interpret this such that the chances of success are maximized? How many statements should I submit? What are they looking for and what do my bank statements tell about me?


$p$ and $q$ orthogonal projections why is it true that the orthogonal projection onto $p(H) \cap q(H)$ is the strong operator limit of $(pq)^n$ ?

Suppose we have a Hilbert space $\mathcal H$, with projections $P,Q$, and let $R$ be the projection onto $P\mathcal H\cap Q\mathcal H$, then I would like to show that $(PQ)^n\to R$ strongly.   We can clearly reduce to the case where $P\mathcal H\cap Q\mathcal H=0$ and $P\mathcal H+Q\mathcal H=\mathcal H$, in which case we must show that $(PQ)^n\to0$ strongly. Now, if the limit $y=\lim_{n\to\infty}(PQ)^n x$ exists, then if it is nonzero, then $$\|y\| = \|PQ y\|<\|Q y\|\le\| y\|$$ which is a contradiction, so once we have convergence, we're done. However, I don't see quite how to show convergence in a general infinite dimensional case.


I have been using the function sys.stdout.write(string) but I was wondering if there is another method for this purpose. Thanks in advance!

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.


Earth is the only planet we know of where life exists.    This sentence is  from the commentary of Planet Earth.  Why it is  know of in this sentence? Can it be know about？  What’s the difference between know of and know about?

Is there a difference between "think of something" and "think about something"? I've also met "have heard of/about something".


;  to find old unanswered inactive questions with low views/votes. Because those kind of questions clutter the site and keep the unanswered question ratio high, it is a good idea to keep the site clean from questions like these. It's very unlikely that someone that asked a question (about a problem) that has been inactive and not popular for more than a year, will still be very active and have the same problem now. So, we worked on . As , we opened  where we can list such questions. As this seems a nice idea, other SE 2.0 communities might benefit by doing the same; feel free to discuss  so that @JeffAtwood might be able automatize this... Until now we've been doing this manually to ensure we don't prune questions of high quality.

Related to Meta Super User efforts:  and Meta Server Fault efforts:  We already auto-remove negatively voted unanswered old questions automatically after 30 days, network wide, with no human intervention required. I was thinking we might extend that to remove old, unanswered zero score questions... based on the following criteria:  fewer than (question age in days * 1.5) views 0 score or lower, or 1 score or lower if the original author is deleted no answers 1 comment or fewer asked more than 1 year ago (thus based on creation date, not last activity date, so , or a user editing it, does not give a doomed question 365 more days of zombie "life")  See the results of this query on:  (10509) |  (787) |  (650) This query has been refined based on the comments, and this is the final version that will roll out tonight. Every site in the network (except metas) will automatically delete old questions that meet this criteria from this point forward.


I'd like to access to the /tilz/scale, the pgfkeysvalueof returns an empty string.  Is there a .store macro dedicated to ?  \documentclass{article} \usepackage{tikz}  \begin{document} \begin{tikzpicture}[scale=2]  \node {*\pgfkeysvalueof{/tilz/scale}*} ;  \end{tikzpicture} \end{document}

Does it exist some tikz register (let say \zoomfactor) that provides the curent scale factor. For example can I do something like :   \begin{tikzpicture}[scale=2]     \begin{scope}[scale=1.5]         \draw (0,0) circle (\zoomfactor);     \end{scope} \end{tikzpicture}   and to obtain circle of size 3=2*1.5 ?


Suppose a baseball is traveling through a vaccum towards another object extremely fast. If it's travelling fast enough then shouldn't its kinetic energy give it enough mass that the observer thinks it should collapse into a black hole and evaporate as Hawking radiation? How can this be reconciled with the perspective of a second object at rest with the baseball, which would have no reason to see a black hole?

I'm a big fan of the podcast Astronomy Cast and a while back I was listening to a Q&A episode they did. A listener sent in a question that I found fascinating and have been wondering about ever since.   From the show :      Arunus Gidgowdusk from Lithuania asks: "If you took a one kilogram mass and accelerated it close to the speed of light would it form into a black hole? Would it stay a black hole if you then decreased the speed?"   Dr. Gay, an astrophysicist and one of the hosts, explained that she'd asked a number of her colleagues and that none of them could provide a satisfactory answer. I asked her more recently on Facebook if anyone had come forward with one and she said they had not.  So I thought maybe this would be a good place to ask.


If you used Google input tools to type in Asian languages when using Microsoft Windows, you might wonder how to do it in Ubuntu...

I am looking for a step by step method for enabling write in indian languages (hindi and gujarati) in Ubuntu applications (browser, LibreOffice, Pidgin etc..).  Could anyone please provide me a method for beginner to do it or simply direct me to the one if you know?


I have a matrix A of dimension 120 x 24000, where the number of features (n=24000) represents voxels in the brain and is greater than the number of observations (m=120), or subject brain scans. I am trying to understand how I can perform PCA on such a matrix. As I understand it, instead of doing the eigendecomposition of the covariance matrix n x n, I can transpose my matrix A and carry out eigendecomposition of the smaller covariance matrix m x m. After obtaining the eigenvalues (120 x 1 vector) and the eigenvectors (120 x 120 matrix), how can I use this to obtain the eigenvectors of the n x n covariance matrix and reduce in voxel space? I apologize for the ignorance- I've performed PCA only when my observations were greater than my features, which is more intuitive to me. But understanding how I can use PCA on a matrix where the number of features is greater than the number of observations is difficult for me to comprehend. Could someone possibly show a simple mathematical example, say of matrix size 3 x 4, to show me the PCA computation step-by-step? Thank you so much.

In PCA, when the number of dimensions $d$ is greater than (or even equal to) the number of samples $N$, why is it that you will have at most $N-1$ non-zero eigenvectors? In other words, the rank of the covariance matrix amongst the $d\ge N$ dimensions is $N-1$.  Example: Your samples are vectorized images, which are of dimension $d = 640\times480 = 307\,200$, but you only have $N=10$ images.


It is apparent to me that the moderators aren't really moderated. I have read many articles where moderators get overzealous in their quest to have "perfect" information.   It's like some kind of cult where if you can get in and follow the creed you can do whatever you want. There's no second opinion and no way to obtain one.  A great example is a question "" It's a good question, but the moderator decides to close it saying It's unclear what you're asking. I know exactly what he is asking. Its very clear to me.   He wants to know, does the internet exist? If so what's the proof?  There is another post here which asks "?" This is a question of the poster's perspective on the moderation. It doesn't address what the community in general things about the moderator. It also appears to be a question of escalation rather than feedback. So I think it is a different question. My question is more about a way for the entire community to give numerical feedback about a moderator's specific action. If the community likes their moderation they can know how much or how little with something like an upvote or downvote. It's a lot of work to "have recourse" on someone and that's not what I'm asking. I'm asking about a way to provide feedback about monitor activity in a non-black and white way. Meaning non-recourse needed, merely "I don't like what you did" way.

One or more of the following things happened to me on a Stack Exchange site:   My post(s) were wrongly deleted or locked by a moderator A moderator posted a wrong comment on one of my posts I was suspended, but did not do anything wrong I asked a meta question, but the question was closed and/or deleted A moderator discredited me in public ...   I think a moderator has abused their power, but I feel powerless against them.  What recourse do I have now? What can I do when I feel that a moderator has abused their power, and has been repeatedly unfair in their dealings with me?


I'm trying to find a tv-series/mini-series that I viewed as a teenager, probably in the 90s, possibly late 80s.  A pair of siblings (twins as I remembers) grow up in a nice neighbourhood. One day an old lady moves in next door.  Soon after, at a birthday the sister gets roller skates and is accidentally hit by a car. When taken to the hospital the doctors find that she doesn't seem to be human (not the right number of organs or something like that).  I can't remember the exact story after that, but it turns out that sister is actually an alien while the brother is a normal human. The neighbour is an alien as well sent to protect the girl. They are at some point attacked by light sabre wielding aliens (looking like big red bears on two legs and made of energy).  As I remember it ends with most of the family (at least the brother and sister) leaving the earth and as the sister leaves she turns into her alien form (lots of white shining light).  I don't think it is US made, possibly Canadian, Australian or from the UK.

Plot of novel: sister is actually some alien planet's royalty but due to a coup d'etat she is surgically changed into a human and sent to live on earth in disguise. Unfortunately they get the wrong planet and gave her two hearts. An accident causes this to be revealed and now assassins are after her.  Aliens were beings of lights and they used water sprinklers as a weapon in one of the fights.


So I am trying to install Internet Explorer on my ubuntu 18. I followed these steps from   sudo apt-get install wine cabextract wget http://www.tatanka.com.br/ies4linux/downloads/ies4linux-latest.tar.gz tar zxvf ies4linux-latest.tar.gz   As I got the ies4linux-latest.tar.gz file and tried to gunzip and untar it, I am getting the below error :   gzip: stdin: not in gzip format   Which means that the file is not properly gzipped and its an HTML or binary or some code. In my case it's an HTML code. So I opened it and had a 1800 line of code.  I tried other links to find the source file but I can't.

When I am try to install Internet Explorer using the command sudo apt-get install wine cabextract) my VLC player gets unpacked/uninstalled/removed.   Please provide me with a suitable command to install Internet Explorer.


I want to use author index with natbib. An example below (with the fix of the author index package) does not work. The fix of  does not work either (with \cite the .idx and .ind files are empty and \aicite gives "Paragraph ended before \@citex was complete.")    \documentclass{article} \usepackage{natbib} \usepackage{authorindex} \let\cite=\aicite \makeatletter % natbib.cfg (copy/pasted from authorindex 2005/03/22 user manual) \AtBeginDocument{% \@ifpackageloaded{authorindex}{%   \ifNAT@numbers     \let\org@@citex\NAT@citexnum   \else     \let\org@@citex\NAT@citex   \fi   \def\@citex[#1][#2]#3{%     \typeout{indexing: [#1][#2]{#3}}%     \org@@citex[#1][#2]{#3}%     \@aicitey{#3}}%   \renewcommand\NAT@wrout[5]{%      \if@filesw{%        \let\protect\noexpand\let~\relax        \immediate\write\@auxout{\string\aibibcite{#5}{#1}}%        \immediate\write\@auxout{\string\bibcite{#5}{{#1}{#2}{{#3}}{{#4}}}}}%      \fi}}{}} \renewcommand\NAT@index{\@bsphack\begingroup    \def~{\string~}\@wrindex{\NAT@myidxtxt}} \newcommand\NAT@myidxtxt{\NAT@name} \makeatother \begin{document} Infinite descent \cite{Fermat1659-DescInf}  \bibliographystyle{plain} \bibliography{\jobname}  \printauthorindex  \end{document}  xeLatex, bibtex, xeLatex, xeLatex works without authorindex the following lines being commented out: %%%\usepackage{authorindex} %%%\let\cite=\aicite %%%\printauthorindex  xeLatex produces the following error with authorindex after \cite{Fermat1659-DescInf}:  Runaway argument? ]{Fermat1659-DescInf}\@aicitey {Fermat1659-DescInf}  ./authorindex-natbib.tex:27: Paragraph ended before \@citex was complete. <to be read again>                     \par  l.27   %%% File authorindex-natbib.bib %%% @unpublished{Fermat1659-DescInf,    author =  {De Fermat, Pierre},    title =   {Relation des nouvelles d\'ecouvertes en la science des nombres},    month =   {August },    year =    1659,    note = {Lettre \`a {Pierre de Carcavi}}, } %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

I can't seem to get the reference within my {refsection}.  \documentclass[a4paper]{article}  \newcommand{\myparagraph}[1]{\paragraph{#1}\mbox{}\\}  \usepackage[     backend=bibtex,     isbn=false,     url=false,     doi=false,     eprint=false, ]{biblatex}  %Point to the bibliography db \addbibresource{mybib.bib}  \begin{document}  \include{myparagraph}  \end{document}   My paragraph file  \myparagraph{\fullcite{dante1320}} \begin{refsection}  \cite{manzoni1827}  \printbibliography[heading=subbibliography] \end{refsection}   I get the first citation (dante1320) right, but the second prints as [manzoni1827]. I don't get any error when I run Bibtex concerning the missing reference. But I got it when I run Latex: LaTeX Warning: Citation 'manzoni1827' on page 2 undefined on input line 5.


Ok so I got on my friend's server the other day and there was text spamming all over the screen. It's still going on! I've tried using.  /gamerule commandblockoutput false   However, it doesn't work. I've also tried to look for the command block. Can anyone help me with ways to get rid of the command block?

I've placed a command block making it day all the time. I want to turn it off, but I've lost it. What's the quickest way to find it?


Issue: I have a car that requires Win.XP Pro 32-bit OS to access and update the software.   Is it possible to install Win.XP Pro 32-bit OS on a MacBook Pro running Mojave 10.14.2?

I have a friend that wants to buy a Mac Book Pro and he has some windows applications that he needs to run. He doesn't want to buy the applications again.  Can he run the Windows applications on his MacBook Pro? What ways to accomplish this are available?