The code below:  function lookForMatches() {     for (var a=1;a&lt;=2000;a++)     {         for (var b=1;b&lt;=a;b++)         {             c=a*a*a+b*b*b;             d=5*c*c;             e=d-4;             f=d+4;             g=Math.floor(Math.sqrt(e))*Math.floor(Math.sqrt(e))             h=Math.floor(Math.sqrt(f))*Math.floor(Math.sqrt(f))             if (g==e||h==f)                 document.getElementById("matches").innerHTML+=c+" ";         }     }     document.getElementById("matches").innerHTML+="Done." }   is supposed to check for Fibonacci numbers in the sequence of the sums of positive cubes, but the output is:     2 5075441272 2976917960 7114243176 Done.   I ran the Fibonacci test manually in Windows Calculator, and although the square root of (5*50754412722±4) is extremely close to an integer value, it's definitely not an integer! I'm not even certain if the number 5075441272 is actually a valid sum of cubes. How large can integer values be in Javascript without introducing roundoff error?
Is this defined by the language? Is there a defined maximum? Is it different in different browsers?
Why do I get a black rectangle instead of my external picture? I write some of my network notes in TeX. I wanted to make a table, and inside it insert an image:   .   I wrote a document:  \documentclass{article} \usepackage[demo]{graphicx} \usepackage{booktabs} \usepackage{array}  \begin{document} \begin{tabular}{m{3cm}m{3cm}m{5cm}} \toprule Configuration for ... &amp; Commands &amp; Topology\\ \midrule PPP: CHAP, PAP &amp; \#sh int se 0/0/0  &amp; \includegraphics[width=4cm, height=4cm]{chappap.png}\\  &amp; &amp; \\ \bottomrule \end{tabular} \end{document}   But instead of my network topology image, I see only this: .   I don't know what is wrong, cause my image is 100% in the same dir, as my *.tex file.  EDIT:  Changed my code as @Jubobs suggested, now everything is as I wanted:  \documentclass{article}     \usepackage{graphicx}     \usepackage{booktabs}     \usepackage{array}      \begin{document}     \begin{tabular}{m{3cm}m{3cm}m{5cm}}     \toprule     Configuration for ... &amp; Commands &amp; Topology\\     \midrule     PPP: CHAP, PAP &amp; \#sh int se 0/0/0  &amp; \includegraphics[width=4cm, height=4cm]{chappap.png}\\      &amp; &amp; \\     \bottomrule     \end{tabular}     \end{document} Response.Redirect to new window I want to do a Response.Redirect("MyPage.aspx") but have it open in a new browser window. I've done this before without using the JavaScript register script method. I just can't remember how? Changing Date format and appending to original file I have file like this called a.txt:  [2016-03-30T04:51:51.599-04:00]!ER_DEV!Port_Conflict!/u05/app/ [2016-01-20T04:30:21.885-04:00]!ER_DEV!Port_Conflict!/u05/app/   I need to modify it so it looks like:    2016-03-30 04:51:51!ER_DEV!Port_Conflict!/u05/app/   2016-01-20 04:30:21!ER_DEV!Port_Conflict!/u05/app/   i already wrote a command to change [2016-03-30T04:51:51.599-04:00] to 2016-03-30 04:51:51 .but how to append the query output to original file.    awk -F'!' '{print $1}' a.txt | awk -F '[T.]' '{print $1 " " $2}' | awk '{gsub(/\[/,"")}1' How does HOTP keep in sync? I'm trying to use a mask to hide a part of a render layer, so that when the render layer is shown over a movie, some parts in the movie will appear to be in front of the render layer.  For example, assume I want to add a box to this image, so that it would look like it's behind the person:    I created the following simple object:    If I render the object, it looks great - the object is solid, everything else is transparent (I didn't use any 'sky'):     Now I create a mask to describe the standing person (or at least the part that would otherwise be covered by the box):    What I want now is to create a "hole" in the rendered box, so that when I use Alpha-over, the box look as if it's behind the person, but I can't find an easy way to do that. My first guess was to use 'Set alpha' to apply the mask (inverted) as an alpha for the rendered layer, but this doesn't look good:    The mask did create a "hole" where it should, but now all the other pixels are not transparent. How can I "retain" the transparent pixels while setting more pixels to be transparent based on the mask (use it as a matte)?  Note: I can do this with (I'm ashamed to say) some math work on the alpha channel, but it just doesn't seem right:    Thanks, and sorry for the [oh so] long question. How do you compare two folders and copy the difference to a third folder? You've got three folders:   folder current, which contains your current files folder old, which contains an older version of the same files folder difference, which is just an empty folder   How do you compare old with current and copy the files which are different (or entirely new) in current to difference?    I have searched all around and it seems like a simple thing to tackle, but I can't get it to work in my particular example. Most sources suggested the use of rsync so I ended up with the following command:  rsync -ac --compare-dest=../old/ new/ difference/   What this does however, is copies all the files from new to difference, even those which are the same as in old.  In case it helps (maybe the command is fine and the fault lies elsewhere), this is how I tested this:   I made the three folders. I made several text files with different contents in old. I copied the files from old to new. I changed the contents of some of the files in new and added a few additional files. I ran the above command and checked the results in difference.   I have been looking for a solution for the past couple of days and I'd really appreciate some help. It doesn't necessarily have to be using rsync, but I'd like to know what I'm doing wrong if possible. When I'm watching a film in Mythtv the screen turns to black every 10 - 15 mins and I have to log back into Ubuntu. Very annoying!  How do I disable the black screen / screensaver / logout in Unity?  There no longer seems to be any options to turn the screen saver off as there were in Ubuntu prior to Unity. Please add a system to allow file uploads attached to questions and answers I posted a question and a couple of respondents asked for the source code. I could only post portions of the code.  If attachments were allowed I could have uploaded a .zip file with the whole application.  Will this be a feature in SO? I have a character playing a multiclass Barbarian/Monk. Does the resistance from rage combine with Deflect Missiles to negate the damage and make the reaction attack? Find the Galois group of $x^3-5$ over $\mathbb{Q}$. In this case, the roots of $x^3-5$ are $\{\sqrt[3]{5},\omega\sqrt[3]{5},\omega^2\sqrt[3]{5}\}.$ I think $\mathbb{Q}(\sqrt[3]{5},\omega\sqrt[3]{5})$ is the splitting field of $x^3-5.$ Then, $[\mathbb{Q}(\sqrt[3]{5},\omega\sqrt[3]{5}):\mathbb{Q}]=3,$ I think the automorphisms are: $$id$$ $$\sigma:\sigma(\sqrt[3]{5})=-\sqrt[3]{5}$$ $$\tau:\tau(\omega\sqrt[3]{5})=-\omega\sqrt[3]{5}$$ I'm not sure about what I have done. But how to determine the Galois group based on this? And how to determine the solvability of this polynomial? How to use more than 10 tab stops in bmatrix or other amsmath matrix environments? I'm using bmatrix environment from the amsmath package, and I'm trying to do something like this:  \documentclass{article} \usepackage{amsmath}   \begin{document}      \begin{equation}          \begin{bmatrix}              1 &amp; 2 &amp; 3 &amp; 4 &amp; 5 &amp; 6 &amp; 7 &amp; 8 &amp; 9 &amp; 10 &amp; 11\\          \end{bmatrix}     \end{equation}  \end{document}   However, pdfLaTeX returns an error: "Extra alignment tab has been changed to \cr", and in the output the extra element is moved to the next row. (If I remove one element, then it works perfectly fine). I guess this means that I've hit some hard limit on the number of tab stops in a matrix. Is there a way to change this?  The elements in the matrix are short and could fit perfectly on a single row. How to implement uniform grids Up until now, I implemented all-against-all collision detection in my games. It worked fine.  But I reached a point where implementing this kind of collision detection, makes the game run poorly, because there are two many objects to iterate through and check for collision.  I have searched this site and found something about 'uniform grids'. But I didn't completely understand what it is and how to implement it. Tried to Google it but nothing easy enough to understand came up.  I am a beginner to 2D-game programming. Do you mind trying to explain to uniform-grids, or link me to some good tutorial?  Thanks a lot I want to remove all empty lines from a file. Even if the line contains spaces or tabs it should also be removed. Does any particle ever reach any singularity inside the black hole? Solve the recurrence relation:$ T(n) = \sqrt{n} T \left(\sqrt n \right) + n$ If you copy the contents of   httpd.conf   and then paste it into a cat command.. such as this one..  #!/bin/bash cat &gt; /test &lt;&lt; EOF pasted here.. EOF   you run into this error:  -bash: command substitution: line 1: unexpected EOF while looking for matching `'' -bash: command substitution: line 4: syntax error: unexpected end of file   perhaps the solution is to escape the dollar signs and maybe even quotes and so on..  but given that this is such a large file.. can dollar signs be automatically be escaped ?  is my only option to escape them via another program and then give it to the cat command ? Is there a word to describe indecisiveness between two things? Possible Duplicate:          Is there a word to describe indecisiveness, specifically between two things? I tried online dictionaries, but did not find anything. In comments, moderators have their diamonds in the OP rectangle:        And in the review (suggested edits), mods have their diamonds outside the blue OP background highlight rectangle:        Of course, it Doesn't Really Matter At All, but it is a small discrepancy (I am not saying that in the review, OP rectangles have a bigger padding). Disk space full but logical space available in database We have a fairly big MS SQL 2008R2 database that resides on a SSD drive. The drive itself only has ~110Gb of space, and the database files are the only files on the drive.  The database is in "Simple" recovery mode, and only has two files, .MDF and .LDF.   The disk is now nearly full: the MDF is currently 109Gb in size. However, SSMS tells me there's nearly 18Gb of "Space Available" (in the 'General' properties page), and if I go through the motions of Shrinking the file it also tells me there's 18Gb of space free. SSMS also tells me the database size is around 132Gb, which surprises me - that wouldn't fit on the drive!  From what I've read, shrink is a really bad idea. However, I'm starting to see replication errors (could not allocate space for object). We've previously tried shrinking the database, but within a few hours the file was back to it's original size.  How should we proceed - given there's apparently 18Gb of free space, should SQL automatically use that free space? Or is it as simple as: we really need more disk space? On all of the other SOFU sites a downvote means The question is unclear or not useful.  However, here on meta, a downvote has become a sign of I don't agree with the question, suggestion, feature request, bug, etc. being described in the question.   What does a downvote on Meta really mean? What other reasons do people downvote on Meta? Why is it okay for meta to redefine the meaning of the downvote?  The tooltips and instructions are all the same here on meta.   Note: I'm not saying I disagree with the practice, just curious.