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Request for Information

  1. Jul 2, 2011 #1
    This is in regard of my thread "Radial Motion in Schwarzchild's Geometry"

    When I posted it the formulas/equations were legible. But for some time I have noticed that the Latex codes are remaining untransformed-----and of course quite illegible. I am particularly concerned about the postings 1,46 and 48 of the above mentioned thread. Some of the vital equations have been boxed off as incorrect.

    When I posted them everything was OK.But now things are totally different.

    It is my request you to view the postings in the above thread and let me know whether you are getting the correct view of the equations/formulas

    Relevant Links
  2. jcsd
  3. Jul 2, 2011 #2

    Doc Al

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    As I mentioned in a PM, I think the issue is that we now use a different Latex plug in: mathjax. Your Latex, which was perfectly fine under the old processor, now has some syntax errors so does not display properly.

    You can try using http://www.arachnoid.com/latex/index.html to test whether code will work under mathjax.
  4. Jul 2, 2011 #3
    They appear boxed to me. The problem is that we recently switched to a new LaTeX-system, and what was ok then, might not be ok now.

    That said, I would like to give you some hints in using LaTeX. You don't have to put { } brackets around everything, in fact it's recommended that you don't (as you will get less errors that way.

    For example your first formula was


    and could just as easily be written as

    \frac{d^2 x^\alpha}{d\tau^2} = -\Gamma^\alpha_{\beta\gamma} \frac{dx^\beta}{d\tau} \frac{dx^\gamma}{d\tau}

    which doesn't give errors:

    [tex]\frac{d^2 x^\alpha}{d\tau^2} = -\Gamma^\alpha_{\beta\gamma}\frac{dx^\beta}{d\tau} \frac{dx^\gamma}{d\tau}[/tex]
  5. Jul 2, 2011 #4
    In response to post 2

    I am getting the correct output after making necessary corrections. The correct code is given below.

    {\frac{{d}^{2}{x}^{\alpha}}{{d}{\tau}^{2}}}{=}{-}{{\Gamma}^{\alpha}}_{\beta\gamma}{\frac{{d}{x}^{\beta}}{{d}{\tau}}}{\frac{{d}{x}^{\gamma}}{{d}{\tau} }}

    When the original posting was made, correct output could be observed. Somehow it changed later. I don't know how!
  6. Jul 2, 2011 #5
    It's probably because the last LaTeX system was not so sensitive about missing brackets. So if you forgot a bracket, then it didn't matter. Right now, it doesn't work if you forget a bracket...
  7. Jul 2, 2011 #6
    Missing brackets were overlooked by the previous software posting the correct output --to the utter amazement of everybody--I would request Doc Al to comment on this statement

    If the old software is there somewhere with you--this anomalous software effect could be easily tested [right now]----to what extent it accepts incorrect postings[in relation to codes--missing brackets and perhaps other things]
  8. Jul 2, 2011 #7

    Doc Al

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    That sounds right to me.

    You can test code using the link I provided in post #2. Your code works with 'CodeCogs' checked (which must be close to our old Latex processor), but not with 'mathjax' checked.

    Maybe you can find an online app that would flag the missing brackets.
  9. Jul 2, 2011 #8


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    I have tested this in the PF Library, which still uses the old LaTeX processor. Indeed, any extra "{" or "}" brackets were simply ignored.
  10. Jul 2, 2011 #9
    Corrections have been implemented by the forum authorities on the affected postings.
    Everything is appearing fine--the equations are no more illegible.Hope they stay like that for a very long time--I am referring to any future implementations of software

    After the edit button goes off the poster/author really cannot do any thing to rectify problems created on old threads/postings by newly implemented software.The only option is to report the matter to the authorities.

    I reported the matter to Greg Bernhardt on 29th June. But there was no reply or response action. Today I reported the matter again to several administrators, mentors and one of the Science advisers. Thankfully I got two reply letters.

    But corrections have been implement only after I put up the matter in the Forum Feedback and Announcement section. It takes time to address a problem --I do admit.

    I am thanking the authorities for their consideration[ with the hope that the corrected equations remain unchanged]
  11. Jul 2, 2011 #10
    The letter has been found.The mistake is regretted

    [I had missed the letter I sent to Greg on 29th June while I was searching through the inbox[sent items]---I thought the software was doing something. But the letter is in place]
    Last edited: Jul 2, 2011
  12. Jul 2, 2011 #11
    Here is the code from an unedited posting [posting 7] of the same thread.The formula of course is illegible even now:


    I never write [itex]

    How did this happen---The new software caused this while it was "Recompiling Old Postings" [I mean the equations/formulas]

    Link: https://www.physicsforums.com/showpost.php?p=3222351&postcount=7
    Last edited: Jul 2, 2011
  13. Jul 2, 2011 #12

    Doc Al

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    The tags must match. You cannot have one end with 'tex' and the other with 'itex'. Making them both tex gives you:
  14. Jul 2, 2011 #13
    This is not an answer: Something which was legible when I posted is illegible now.
    Moreover I never use itex.
  15. Jul 2, 2011 #14
    I don't understand, you weren't the user that posted that. It was Mentz that posted it...
  16. Jul 2, 2011 #15
    Testing in the library tells me that in the old LaTeX system the [ tex] and [ /tex]-cases didn't have to match. So we could easily write [ itex]x^2[ /tex] and it would work. The system now is much more sensitive.
  17. Jul 2, 2011 #16
    Its true Mentz posted it. Quite unusual that he did not notice his mistake[or may be he did not correct it]--but it is not impossible.

    The new software recompiles old threads apart from compiling the new ones[the currently inserted codes] ----------- you must be subscribing to this view.
  18. Jul 3, 2011 #17
    Matter of Concern: My last posting in the thread " Radial Motion in Schwarzschild" has been deleted.

    Incidentally, the number of viewers in with this thread have been steadily increasing.Obviously they were going through the plight of reading illegible equations

    It was quite possible that readers could have held the author responsible for putting up incorrect equations.Did they have any way to ascertain that the old software was not sensitive to missing brackets?[Incidentally the old software did not inform me of any mistake I made-----It has been assumed by the authorities with certainty that a mistake committed]

    I had put up this information with the last posting in the concerned thread to make the visitors aware of the fact that I did not have any intention of causing a strainful reading for them.
    The authorities took a wise wise decision to delete the posting[the word thread has been replaced by the word posting]

    [In the first sentence the word posting was already there--it stays unmodified]
    Last edited: Jul 3, 2011
  19. Jul 3, 2011 #18


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  20. Jul 3, 2011 #19
    My enquiry relates to the deletion of the recent post. That was clearly indicated
  21. Jul 3, 2011 #20

    George Jones

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    I deleted the post. Posts in the Special & General Relativity forum should have physics content; your post had no physics content.

    No, the view count for the thread has been going up because Mentors have been fixing your broken code, and have been having look just to see what all the fuss is about. I have viewed the thread more than a dozen times in the last day, and I didn't do any of the the work fixing your code.
    Are you accusing the Mentors of dishonesty?

    1) You have been told that your code had mistakes.
    2) Mentors (not me) have spent a substantial amount of time fixing your mistakes.
    3) Mentors have tested your code with the old and new software (again, not me), and they have confirmed that different outputs were produced.

    Are you grateful? No, you continue to make accusatory, arrogant, and whiny posts. Why can't you just own up to your mistakes? Everyone occasionally makes these types of mistakes.
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