Rand in high tables
quick selection of a random row from a large table in mysql
Report this Ad Feature How to put a variable in anchor tag A virtual file containing the concatenation of other files Is there a way of creating a filesystem object akin to this:  mknod files p cat file1 file2 ... fileN &gt; files   but such that it can be seeked in, as if it were a regular file? Punctuation in an indirect quotation Consider the brief passage:     "I love your work, but calling you 'the artist' {1} just doesn't seem to be   cutting it anymore. What shall I call you?"      "OK. Call me George." {2}   So my instincts tell me to put {1} in single quotes as opposed to no punctuation (or perhaps even italics) but to do the opposite for {2}. Is this right? Why?  Let me expand this one further iteration:     "Wow, that's a great name, especially with this crowd. Maybe for your next book    you should call yourself Ringo."{3} Split string into sentences using regex "done" vs "have done" I'm using PostGIS 1.5.2, with geometries in SRID:900913. I need create a circles using a list of points as centre, with a radius of 600 kilometers. I'm using this query:  INSERT INTO circles (geom) (    SELECT ST_Buffer(point, 600000, 'quad_segs=8')     FROM points );   But circles created have not 600 kilometers of radius (radius is near this length, but not exactly).  Are there other methods to create circles in PostGIS?  NOTE: Information represented is from Spain. Correct projection is 4326, but client use Google rasters, so I am storing data in 900913 to avoid reprojections and increase performance. Evaluate $\sum\limits_{k=1}^{n} \frac{k}{2^k}$ Evaluate $$\sum\limits_{k=1}^{n} \frac{k}{2^k}$$ My website is javatechig.com and is around 6 months old. I have used All-in-One SEO WordPress plugin for SEO tricks. Definitely after using SEO plugin, my website page view is increased, but still it is not giving one good site-link in Google Search.   I have followed the following steps:   Created sitemap.xml and submitted to Google Webmaster Tools Edited all posts with meta tags Header tags are carefully taken care   I want to make a sitelink similar to the attached image: cant install or remove anything on 18.04 cause of DPKG error Given a function:  function x(arg) { return 30; }   You can call it two ways:  result = x(4); result = new x(4);   The first returns 30, the second returns an object.  How can you detect which way the function was called inside the function itself?  Whatever your solution is, it must work with the following invocation as well:  var Z = new x();  Z.lolol = x;  Z.lolol();   All the solutions currently think the Z.lolol() is calling it as a constructor. How do I make Units efficiently? I just blew almost all my money on a really cool lookin' ship. How do I regain solvency without spending a lot of time fiddling around in my inventory?  At the moment I've found a sequence of steps that'll turn 50 carbon and 100 Plutonium into ~5000 Units (by creating Suspension Fluid and then turning it into Electron Vapor). Are there better recipes or sequences of recipes I should look for? Or should I just drop the whole thing and go mine a particular mineral? What's the fastest way to find mineshafts? , and one place I'm fairly sure I can find them is a mineshaft.  Which leaves me back at square one, how do I find a mine shaft?  It seems they were made substantially harder to find between 1.8 and 1.0.  What's the fastest way to find a mineshaft? How about a difficulty rating for questions? It might be useful to add a drop down field "Difficulty" for questions. With a very limited set of options, say:   Beginner Advanced Expert   This way, users could easily judge if they can answer a specific question (depending on their experience in the topic) and how much time it will probably take.  Beginners usually know they are new so they can easily select Beginner. Those with some experience just select Advanced and those working on a topic for years may chose Expert. I think it's not very difficult to judge halfway correctly.  And the difficulty rating does not have to be very precise anyway, it's more a rough estimate by the asking person.  As an addition, rep gained on this topic can be multiplied with a difficulty factor. This would solve the problem of lots of rep for often-viewed and easy to answer questions and few rep for less-viewed, difficult questions.  Update  Thank you so far for the answers. I clearly underestimated the fact that some users are going to always chose Expert difficulty.  Maybe readers voting on the difficulty would be a workaround. Of course, we cannot use the rep factor then, for the same reason.  This kind of voting would obviously introduce a whole new set of issues, since we could vote on both content and difficulty (I'm almost positive this kind of proposal existed before?). Is there a rule in British English about how to pronounce "either"? In Random forest algorithm, Breiman (author) constructs similarity matrix as follows:   Send all learning examples down each tree in the forest If two examples land in the same leaf increment corresponding element in similarity matrix by 1 Normalize the matrix with number of trees   He says:     The proximities between cases n and k form a matrix {prox(n,k)}. From their definition, it is easy to show that this matrix is symmetric, positive definite and bounded above by 1, with the diagonal elements equal to 1. It follows that the values 1-prox(n,k) are squared distances in a Euclidean space of dimension not greater than the number of cases.    In his implementation, he uses sqrt(1-prox), where prox is a similarity matrix, to convert it to distance matrix. I guess it has something to do with the "sqaured distances in a Euclidean space"-quoted above.  Can somebody shine a little light on why it follows that 1-prox are squared distances in a Euclidean space and why he uses squared root to get distance matrix? How do you detect where two line segments intersect? After reading some articles on blender speed, I see that using CUDA enabled GPU computing will be of help in rendering.   I am trying to stitch a shirt on human .obj file. For that I bake 60 frames for it to fall on the human correctly. It takes about 20 seconds for the bake. I'd want to host it real time.  youtube link of the same :   Can I use GPU computing to reduce the bake time just like rendering time ? How to print the name of missing files in a folder? Remove association with blank file extension?