LaTeX preview solution

1. Sep 21, 2010

Greg Bernhardt

https://www.physicsforums.com/mathjax/preview.html [Broken]

Works best in Chrome. In FF there is a permission problem and the font is a little crude.

I'll look to see how we can add this to the post editor.

Last edited: May 4, 2017
2. Sep 21, 2010

Redbelly98

Staff Emeritus
Cool! Works in FF for me (with Windows XP Pro)

Thank you Greg, I'll add it to the LaTeX sticky.

3. Sep 21, 2010

~christina~

I am sad to report that it did not work for me. The one in the link that someone else posted in the other thread did, however.

I typed something into the text box and clicked the side space and nothing happened.

4. Sep 21, 2010

MysticDude

Thank you so much for this! I was having some trouble with my previews when replying to people and this will come in handy a lot! Thanks again! Went straight into my bookmarks when I saw it's capabilities.

5. Sep 22, 2010

Gokul43201

Staff Emeritus
Works in FF 3.0 on OS X.

6. Sep 22, 2010

Gokul43201

Staff Emeritus
What browser and OS is this on?

7. Sep 22, 2010

Staff: Mentor

Works under Opera/Windows XP.

8. Sep 22, 2010

DrGreg

Works with Firefox 3.6.9 under Vista, but the very first time I used it, it took about 5-10 secs to get the preview, after that it was very fast.

It doesn't work with Internet Explorer 8.0 under Vista: the displayed preview is always "You typed: ${}$" and messages at the bottom of the screen say that various JS files failed to load.

9. Sep 24, 2010

collinsmark

Just in case anybody might be interested, I think I know the root cause of the weird LaTeX issue that everyone seems to have trouble with.

If I had to guess, the original LaTeX issue involves the browser's cache combined with the way PF assigns file names to graphics.

I'm not certain that is the case, but suspect that it's at least something like it. Here is a more detailed scenario of what I'm suspecting:

(a) User originally hits the preview button.
(b) PF processes the LaTeX code, and creates .png graphics files of the equations. Each .png graphics file gets assigned a name and a corresponding link (something or other short of like https://www.physicsforums.com/latex_images/28/2886657-0.png" [Broken], but with a slightly different location [in a special "preview" directory] and a different file name).
(c) The image gets downloaded to user via normal http protocol and displayed on the screen
(d) The link is also cached locally on the user's machine.
(e) The user makes an edit to the equation and previews it again.
(f) PF creates a new graphic overwriting the old image, re-using the same file name.
(g) Via http protocol, browser thinks that the local cached graphic is the same graphic as the one on the server (after all, they share the same URL and file name).
(h) Cached graphic gets displayed on the browser.
(i) Only by hitting "refresh" will cause the browser to reload the server content, bypassing the cache.

A solution to this might be to change the algorithm making sure that the PF server does not recycle file names for previews. Of course, that means that more graphics files get stored on the server. So maybe a fix might also involve automatically deleting "preview" graphics files after the preview session is complete, but still not recycling file names (the index for the file names keeps incrementing, even if the files are deleted).

Last edited by a moderator: May 4, 2017
10. Sep 25, 2010

Staff: Mentor

Under Opera it is enough to right click the LaTeX png and select Reload image.

11. Sep 25, 2010

~christina~

This was what I was seeing.

It works on firefox 3.6.10 for me.

12. Nov 14, 2010

Bob S

If I am working on a post, especially one that includes Latex, and I need to leave my computer for an extended time, is there a good way of saving the post and previewing it without actually submitting it? Should the blogs be used in this way?

Bob S

13. Nov 14, 2010

Staff: Mentor

I would copy paste to notepad and saved locally.

14. Nov 14, 2010

Redbelly98

Staff Emeritus
That's exactly what I do, and then I delete the Notepad text after I have made the post.

15. Nov 15, 2010

Bob S

I would like the Latex \operator for Dirac bras and kets: <ψ*|function|ψ>. Is there a complete reference for Latex symbols?

Thanks.

16. Nov 15, 2010