----- Original Message Follows ----- From: Devon McCormick <[email protected]> To: Programming forum <[email protected]> Subject: Re: [Jprogramming] math.pdf -> J Server -> math.ijs file Date: Fri, 19 Jun 2009 21:06:48 -0400 > I searched for "physics formula" in Google, >grabbed the first PDF Ifound >(http://faculty.trinityvalleyschool.org/hoseltom/handouts/F >ormula%20Sheet-2003-05-07-8pg.pdf),opened it in Acrobat, >highlighted a formula for "Density = mass/volume"which was >written as something like: {rho} = m _ >(unit:kg/m{exponent} 3) vand grabbed this >formula using the Acrobat selection tool. In a textwindow, >this pasted as(unit : kg /m3)Vñ = mSo that's one problem. I downloaded the same .pdf file and ran a free-pay-if-you-like-it program that extracts text from a .pdf file. My results for the same density function: #4 Weight = m<8f>g g = 9.81m/sec² near the surface of the Earth = 9.795 m/sec ² in Fort Worth, TX Density = mass / volume If I take this apart, #4 Weitht = m<8f>g is not correct because I don't have a definition for the round dot for multiplication the next line is correct the next line is correct The next line looks like a big mess. () 3 /: mkgunitV m= ? as you say, it should be: rho = m/V(unit:kg/m^3) But looking at it, the problem is the way the text was processed. every letter is there, it is the order that is bad. The "(" and ")" are there, the "/" is there, the "kg" is there, the "m" is there, the "3" is there the "V" is there.
the reason the 3 is not displayed as an exponent is because of font support I am not sure where the rho went, but I think it has to do with not having the proper font support. If you have the proper fonts installed, everything will be displayed, and if one were to make the code process the text properly, your formula would be correct. >However, the deeper problem is that _there is nosuch thing >as a standard mathematical notation_. Even on the single >physicsformula page I looked at here, multiplication is >represented both implicitlyby adjacent letters and >explicitly by a big, vertically-centered dot.Even on this >one page, equality is parsed in differen t, inconsistent >ways.The intended meanings are clear from context and a >familiarity with physicsbut are ambiguous taken by >themselves. I could go on and on - take a look >athttp://www.jsoftware.com/jwiki/NYCJUG/MathematicalNotatio >n for a little moreon this - but I won't. I totally agree with you, this is pain in the ass. >This inconsistency of notation is, in fact, part ofthe reason >Iverson created APL in the first place. great idea from a great man. >The upshot is that >an idea like Dan's is probably more fruitful than >thisnotion of grabbing things off a PDF. Even then, you'll >need to spend a fairamount of time interpreting what you >get. I respectfully disagree. The program I am using does a fair job proving to me that it is fisable. >For a look at how someone handles a lot of formulas and >translates them intoJ, see Tom Allen's pages starting >athttp://www.jsoftware.com/jwiki/Essays/SpaceTime2D/SpaceTi >me2D01.Good luck,DevonOn Fri, Jun 19, 2009 at 8:24 PM, ><[email protected]> wrote:> I do not plan to >use OCR.>> I am thinking more along the lines of cutting >and pasting a> section out of a> Portable Document Format >(pdf) file that represents in> normal> mathematical >notation a formula.>> Acter doing the copy, use cut/paste >buffer to generate> equivalent j code.>> As I understand it >( probably wrong ) what is in the> cut/paste buffer is a >sequence> of bytes which represents in pdf the formula. I >am thinking> that different formulas> ( no matter how >little or how big the difference ) have> different bytes. >So, no matter> how difficult, one should be able to >transcribe from pdf> representation to j representation.>> >I think it would be way cool (1960s euphemism) to go to a> >web page containing formula> for Physics and copy a pdf >version of a formula and then> turn it into the j >representation> automatically.>> ----- Original Message >Follows -----> From: bill lam <[email protected]>> To: >[email protected]> Subject: Re: [Jprogramming] >math.pdf -> J Server -> math.ijs> file> Date: Fri, 19 Jun >2009 10:09:30 +0800>> >Except for the ocr part, looks >similar to mathematica.> >> >btw the 'Quality' Web Email >you used breaks every thread it> >replies.> >> >--> >>regards,> >===== >===============================================> >GPG key >1024D/4434BAB3 2008-08-24> >gpg --keyserver subkeys.pgp.net >--recv-keys 4434BAB3> >>---------------------------------------------------------- >-> >----------- For information about J forums see> >>http://www.jsoftware.com/forums.htm> >----------------------------------------------------------- >-----------> For information about J forums see >http://www.jsoftware.com/forums.htm>-- Devon McCormick, >CFA^me^ at acm.org is mypreferred >e-mail----------------------------------------------------- >-----------------For information about J forums see >http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
