@NasserM.Abbasi perhaps something got erased? you can check if it's downvotes and for which answer/question on your profile page (click on reputation, then select "post" below it)
@NasserM.Abbasi You had answered a trivial localized question (voted -4) that was closed by 5 users and then deleted by 1 vote from a user and 1 vote by a moderator (me). So you lost a net of 7 upvotes * 10 + 15 accept = 85 points. (cc @MarkMcClure @acl). To recap (for those that can't see it), it was a question on how to import an image from a URL and the problem was that the OP hadn't used the URL of the image.
I was just trying to look at the number of users and traffic. Is there a good place to see these stats. I knew once upon a time that someone was keeping track of this but I've not been that active on meta and such and don't remember where to look.
@Szabolcs That's not updated anymore. I'm thinking of starting a quarterly update series on meta, to share the (sanitized) statistics with the community. Will probably make the first post for our 1 yr anniversary, which is in about a month
@rm-rf I see that was posted on the 1st of October. It got so many views already on the first day? It wasn't the WRI blog post that caused all those views (131434 today)?
@Szabolcs Yes, all those views in the first day... as usual, I posted it to reddit, where it exploded. And by exploded, I mean EXPLODED. Page view counts kept jumping by the thousands every time I'd refresh the page
Later in the day, another user shared it on HN, where it again took off and sustained the view count. By then, a million copy cats sprung up all over SO and TeX.SE, trying to recreate xkcd in R, MATLAB, Java, C#, python, you name it!
The 3 spikes that you see are (in order): my bagel question, the xkcd question and the mars rover question
I wonder how much the core language has changed since then. I remember some weird pattern matching behaviours have been cleaned up in 6, but I never really understood those dark corners anyway
@Szabolcs aside from new functionality the core language is probably pretty similar. That is not saying that it doesn't radically improve with each version. There is always active development going on at just about every level. I actually find these unadvertised enhancements, speedups and tweaks to be the biggest incentive to upgrade.
Hi!.. I have a website for students here in Brazil. I would like to know if I can use the StackExchange structure inside it. Someone knows? There is an API so I could install it in my server?
@Szabolcs I know I pointed that one out (not sure if I was first). I don't have any definitive ones to point out off the top of my head beyond say big speedups in date handling.
@NasserM.Abbasi I just wanted to report this issue, but obviously restarting Mathematica helps. So the bug depends on 2 hours of in- and output. Those are the most fun to track down :-(
We developers pick up new tricks all the time just like users do so when we improve some code it is just natural to look over the code to find other places that might benefit from a new trick or realization.
@halirutan, I'll have to pick this up later, I'm shutting down to travel, but will try to see if there's anything I can help with, even if just for the future.
MMA 8 or 9; Insert menu; Table / Matrix item; "Draw lines between rows" produces nice input display ... now I want to draw lines dividing a 4x4 matrix into 4 2x2 matrices, but doing // FullForm or // InputForm on the output fo the above doesn't reveal clues... any clues from you-all :) ?
@Nass agreed Latex is cleaner ... my REAL deeper question has to do with the Insert menu, Table / Matrix item produces something in the notebook that I can't analyze with // <Foo>Form ... exposes my ignorance :)
I use this function sometimes to make divisors easier:
(*-------------------------------------------------------------*) (* Thanks to Heike @SO for this function for making grid line *) (*-------------------------------------------------------------*) myGrid[tab_, opts___] := Module[{divlocal, divglobal, pos}, (*extract option value of Dividers from opts to divglobal*) (*default value is {False,False}*)
divglobal = (Dividers /. {opts}) /. Dividers -> {False, False}; (*transform divglobal so that it is in the form {colspecs,
@rm-rf you'll see that there is a slip -- it puts the second row of the upper-left 2x2 block on the upper row of the upper-right 2x2 ... your code scrambles my matrix a little ...
@Rojo, this function by Heike allows one to add horizontal divisor at point the command is used (i.e. in place) so easier to control where to add the divisor. Grid other divisor options can still be used (i.e. for vertical)
For latex, one tells its where to put the vertical lines at using \begin{tabular}{| l |} at the start, then adds a horizontal line any time needed using \hline. i.e. between rows. if one does not need divisor, then do not write \hline there.
if you want vertical line evey other column, write \begin{tabular}{| c c | c c | } etc.. letter inside the || are for alignment
@belisarius and now the social network world has had the most incredible immediate reaction I have ever seen to a piece of news with that Marita Veron's verdict
Is it appropriate to post a question about the mma software itself (rather than a "How do I do...?" in the main mma forum? If not, where should it be done?
For example, I have found that the help documentation becomes unresponsive quite often in v9. I rarely had that problem in v8 and below, but it is very freq under v9. Wondering if anyone else is experiencing the same...
@MikeHoneychurch I am hoping they would switch to a faster release cycle for major versions too ... one version every two years feels a little slow these days.
@MarkMcClure I was wondering myself. His profile says, "On an extended and much-needed hiatus from the StackExchange network."
@JohnD on my Mac, Mathematica 9 seems more responsive. It doesn't seem to hang (spinning beach ball of death) as much, and help is much faster. Now there are still issues with bugginess of the code contained in the help documents...
is there benefit to having wolfram alpha pro, if I have mathematica on my laptop? Does anyone find it more convenient, nicer, etc.? It's only 5 /mo, and I was thinking about taking the plunge but I also spent 2500 on Mathematica :-)
I have the following expression:
expr=(Sqrt[2]r Sqrt[(4+r^2) (2+r (r+Sqrt[4+r^2]))])/(4+r (r+Sqrt[4+r^2]))
Then
FullSimplify[expr, r > 0]
just returns the expression. However
Plot[expr, {r, 0, 10}]
shows that it is just r in disguise. Is there any way I can tell Mathematica to be sm...
@Szabolcs I think it is only interesting in the fact that the OP assumed that Mathematica could solve anything and gave up when he discovered it couldn't. But, that may be me just being cynical.
@rcollyer I don't often see expressions like this that can be simplified but it cannot do the simplification. Usually it turns out that the simplification doesn't hold for all values of the variable. But not in this case.
@MarkMcClure I didn't manage to embed it. You can link to it though ... Probably embedding is disabled because of security. What I tried was simply putting the embedding HTML in the post, but object tags seem to be disabled.
@MarkMcClure Well, it really provides just a basic OO functionality. Not really fast,alas. But should not be too slow, either - just a usual top-leveloverhead plus a bit of extra method call overhead due to method lookup
@MarkMcClure Once I finished this (which was aby-product of something else I was doing), I looked at the classes.m by Roman Maeder (never studied that code carefully), and found that I used similar idea, but I was able to keep the nice pattern-based syntax,which I think is a big win
I'm wondering if anyone has written a set of functions for video editing. I have a bunch of video that I would like to apply effects to. Since Mma. doesn't seem to support video with sound, I suppose it would have to rejoin them with ffmpeg or something.
@MarkMcClure Well,my understanding is that the link is eternal, at least unless the owner (myself here) deletes the gist, or if Github goes out of business (unlikely:)). But I plan to soon complete the code exchange system for SE, and there we will also have a backup option, so anyone who publishes code will have an option to back it up, and the maintainers of the main repo (perhaps, several of us) could get everything on their machines. So, I hope that soon this will be no problem at all.
@MarkMcClure Besides, I plan to later introduce another layer of indirection, so that the indentity of the project will be determined by its name etc,rather than by the url.
@rm-rf I've encontered similar problems before. My experience is that the indefinite integral followed by manual limit substitution is usually correct while the definite integral is often not (meaning some kind of a bug)
@LeonidShifrin Yes, I'll have to think of the problem a bit if the indefinite is the correct answer. I don't think it is, because I have scribbled down in my notes a general formula based on hypergeometric functions that I got from a table and it is closer to the definite integral result... I unfortunately, didn't write down which table/reference (I never do that!). Now I've to hunt that ref down! grrrr
@rm-rf Definite integration algorithms are totally different from indefinite. Definite integration issues often involve branch cuts in the complex plane. Dan Lichtblau knows a lot about this sort of think. I'd throw this question at him.
@rm-rf Yep. Should be a matter of 10-15 minutes for me, I guess, if not less. You can substitute x -> ix, then do the trig substitution, then it should reduce to a beta function
@LeonidShifrin Ok, back to my notebook (I'll admit, I was lazy to try it by hand because I found it in a standard table... and because this is only a tangential item in the appendix)
@Szabolcs Oh, I see. I had some similar issue but I changed code a bit and it seemed to have gone away for me. It is related to the formatting rules for objects that I introduced.
@LeonidShifrin It looks like the formatting is not displayed correctly in the predictions bar. I'd say it's a prediction bar problem (bug), perhaps you can let WRI know about it.
@rm-rf Well, you don't have to do all the steps by hand, you can use Mathematica for each step, to do the substitutions etc - but not to compute the final integral
@Szabolcs How do I reproduce it? Did you find it on Mac or Windows?
@LeonidShifrin Mac, just evaluating your example notebook. But the suggestions bar is learning what to suggest, it might suggest different things for you than me
I see. I will look into it when I get a chance to work on a Mac (soon, I hope). For the time being, I'll just modify OO so that the formatting can be switched off.
@Szabolcs but does this totally prevent you from getting something sensible out of the notebook?
@rm-rf Then this seems to be a non-typical case - at least for me, it usually worked the other way around. But I did not do any serious stuff with integrals for a while now.
I have the following expression:
expr=(Sqrt[2]r Sqrt[(4+r^2) (2+r (r+Sqrt[4+r^2]))])/(4+r (r+Sqrt[4+r^2]))
Then
FullSimplify[expr, r > 0]
just returns the expression. However
Plot[expr, {r, 0, 10}]
shows that it is just r in disguise. Is there any way I can tell Mathematica to be sm...
