# latex.mathoverflow.net/png images broken

Prior to MathJax and jsmath, MathOverflow used http://latex.mathoverflow.net/png to generate images of mathematical equations to insert in posts (e.g. this one). That didn't last very long but all of those image links are currently broken.

• Could it be a good occassion to instead of fixing this get rid of it? How many question should there be that might be affected (I have no idea how long this was used)? This seems even somewhat more feasible in view of the fact that the posts are not turned unreadble. – user9072 Jul 4 '13 at 20:38
• Sure thing. Go ahead! – François G. Dorais Jul 4 '13 at 23:41
• Is there any way for moderators to "edit" the comments that need to be LaTeX-ified, or to replace them with latexified copies? – Andrés E. Caicedo Jul 4 '13 at 23:54

These are the questions provided by m0sa (thank you!), that would contain the type of "LaTeX" that creates problems. (Please note that at the moment it works, so the post does not look broken, but looking at the source it will be clear that this is done different from how it is done now.)

Everybody who is in an editing-mood can pick a post here and add MathJax. After having completed it, please strike-out the post (rather than delete) from this list.

As Andrew Stacey said let us try not to make too many at once. (The revision history of this question could serve as a guide to know how many were done in the recent past.) At the bottom there are three comments where moderator powers wouls be needed. (I also put the corresponding questions there to minimize bumps.)

Still to do:

# All done

Completed:

http://www.mathoverflow.net/questions/4516

http://www.mathoverflow.net/questions/4473

http://www.mathoverflow.net/questions/4615

http://www.mathoverflow.net/questions/4625

http://www.mathoverflow.net/questions/4658

http://www.mathoverflow.net/questions/4601

http://www.mathoverflow.net/questions/4494

http://www.mathoverflow.net/questions/4664

http://www.mathoverflow.net/questions/5161

http://www.mathoverflow.net/questions/5321

http://www.mathoverflow.net/questions/5338

http://www.mathoverflow.net/questions/4429

http://www.mathoverflow.net/questions/4083

http://www.mathoverflow.net/questions/4115

http://www.mathoverflow.net/questions/4121

http://www.mathoverflow.net/questions/4125

http://www.mathoverflow.net/questions/4128

http://www.mathoverflow.net/questions/4130

http://www.mathoverflow.net/questions/4135

http://www.mathoverflow.net/questions/4169

http://www.mathoverflow.net/questions/4174

http://www.mathoverflow.net/questions/4180

http://www.mathoverflow.net/questions/4193

http://www.mathoverflow.net/questions/4233

http://www.mathoverflow.net/questions/4246

http://www.mathoverflow.net/questions/4268

http://www.mathoverflow.net/questions/4276

http://www.mathoverflow.net/questions/4296

http://www.mathoverflow.net/questions/4333

http://www.mathoverflow.net/questions/4406

http://www.mathoverflow.net/questions/4409

http://www.mathoverflow.net/questions/4422

http://www.mathoverflow.net/questions/4424

http://www.mathoverflow.net/questions/4452

http://www.mathoverflow.net/questions/4456

http://www.mathoverflow.net/questions/4459

http://www.mathoverflow.net/questions/4460

http://www.mathoverflow.net/questions/4672

http://www.mathoverflow.net/questions/4674

http://www.mathoverflow.net/questions/4709

http://www.mathoverflow.net/questions/4728

http://www.mathoverflow.net/questions/4779

http://www.mathoverflow.net/questions/4851

http://www.mathoverflow.net/questions/4865

http://www.mathoverflow.net/questions/4939

http://www.mathoverflow.net/questions/4966

http://www.mathoverflow.net/questions/5006

http://www.mathoverflow.net/questions/5008

http://www.mathoverflow.net/questions/5013

http://www.mathoverflow.net/questions/5044

http://www.mathoverflow.net/questions/5064

http://www.mathoverflow.net/questions/5103

http://www.mathoverflow.net/questions/5122

http://www.mathoverflow.net/questions/5144

http://www.mathoverflow.net/questions/1845#comment-6101

http://www.mathoverflow.net/questions/4180#comment-4382

http://www.mathoverflow.net/questions/4429#comment-4719

• (I only accepted to improve visibility.) – François G. Dorais Jul 7 '13 at 17:46
• Couple of lessons from doing a couple of these: there may be more than one part of the post that needs fixing (ie check the answers too, and take the opportunity to fix minor things in those since the whole thing will be bumped anyway); and the "alt" text may not fully correspond to what is in the image. – Loop Space Jul 8 '13 at 10:01
• Oh, and not all of these questions are questions. Some are answers. So if fixing more than one issue in a question-and-answer list, it will be that the answer should also be struck out (if you can locate it in the list). – Loop Space Jul 8 '13 at 10:07
• Thanks to everybody who contributed so far, and especially to @AndrewStacey for the remarks. I was aware of the answer-issue but did not know the potential "alt" text problem. In any case, once this is completed/close to completion I will double-check the changes. – user9072 Jul 8 '13 at 19:32

Upon discovering that the question linked in this question was mine, I decided to fix it and discovered also that a simple regexp would not suffice. Sometimes it should have been displayed maths, sometimes not, and there were sufficient other small changes that I felt it needed a person to do. For example, not every mathematical phrase in that series of questions and answers was sent off to latex.mathoverflow.net, and I'd used the \sb command to get round the dodgy parsing of underscores (seems this isn't supported by MathJaX).

Is the list of questions using latex.mathoverflow.net very long? Maybe you could post the links and then kind hearted users could (slowly!) go through them and fix them. Say, no more than 5 a day to avoid flooding the active tab?

• It seems a bit stupid that you work a lot with this and then get get a downvote as a result... – András Bátkai Jul 5 '13 at 10:02
• @AndrásBátkai I found that highly amusing. But it did make me realise that when editing old posts it is probably a good idea to state that this post is ancient history and so voting on it just because it is on the active list is a bit pointless. – Loop Space Jul 5 '13 at 10:12
• I tried to search for latex.mathoverflow.net on the site in order to identify posts for manual fixing, however this seems to fail both with the search on the page as well as with Google; presumably one would have to search the database or a dump. Now, likely I could somehow manage to do this, but I never did, while I have the impression some do this all the time, so I will wait for a while if such a list is created by somebody who can do this more easily then me before venturing to create it myself. – user9072 Jul 5 '13 at 12:46
• @quid Yes, it would be easiest from the database dumps as the text latex.mathoverflow.net doesn't appear on the pages but only in the page source. – Loop Space Jul 5 '13 at 13:12
• see my answer meta.mathoverflow.net/questions/374/… – m0sa Jul 5 '13 at 16:08

I ran a quick query, here are the non deleted posts and comments containing latex.mathoverflow.net/png in CSV format: http://pastebin.com/2ffiacNF

I propose we ask the Stack Exchange team if they can do a search and replace on the database for us.

As an example, we want to replace

![\sum\sb {n \ge 1} \frac{1}{n} \cos(n \pi t)](http://latex.mathoverflow.net/png?%5Csum%5F%7Bn%20%5Cge%201%7D%20%5Cfrac%7B1%7D%7Bn%7D%20%5Ccos%28n%20%5Cpi%20t%29)


with

$\sum\sb {n \ge 1} \frac{1}{n} \cos(n \pi t)$


It's probably a reasonable thing to do with a regular expression!

• Would not be better to have displaystyle here? – András Bátkai Jul 5 '13 at 6:44

In the meantime, I got the script that produces the images running again. I don't think this is a good solution, short term or long term.