       Re: ToExpression[..,TexForm] does not seem to work on

• To: mathgroup at smc.vnet.net
• Subject: [mg104386] Re: [mg104351] ToExpression[..,TexForm] does not seem to work on
• From: Bob Hanlon <hanlonr at cox.net>
• Date: Fri, 30 Oct 2009 02:17:06 -0500 (EST)
• Reply-to: hanlonr at cox.net

Put a space after sum in the TeX

s = TeXForm[Sum[f[n], {n, 1, m}]]

\sum _{n=1}^m f(n)

Note the space after sum in the above output

ToExpression["\\sum _{n=1}^m f(n)", TeXForm]

Sum[f[n], {n, 1, m}]

ToExpression["\\sum _ {n=1}^m f(n)", TeXForm]

Sum[f[n], {n, 1, m}]

Bob Hanlon

---- "Nasser M. Abbasi" <nma at 12000.org> wrote:

=============
Version 7.

Some Latex commands are converted ok to Mathematica expressions, such as:

ToExpression["\\sqrt{3}", TeXForm]
ToExpression["\\frac{a}{b}", TeXForm]

But the next Latex "sum" command does not seem to work. Is this a known
"issue" or is there a trick for one command?

I take the output of the TexForm command, and then try to convert it back to
Mathematica expression, but the conversion back fails:

s = TeXForm[Sum[f[n], {n, 1, m}]]
ToExpression[ToString[s], TeXForm]

Even when I type the Latex output by hand, it does not work:

ToExpression["\\sum_{n=1}^m f(n)", TeXForm]

the error is :

Syntax::sntxi:Incomplete expression; more input is needed.
ToExpression::esntx:Could not parse \sum_{n=1}^m f(n) as Mathematica input.

--Nasser

• Prev by Date: Re: ToExpression[..,TexForm] does not seem to work on some Latex commands?
• Next by Date: Re: Distribution of state occupancies in a multistate Markov model
• Previous by thread: Re: Re: Opportunities and Player Pro
• Next by thread: Re: ToExpression[..,TexForm] does not seem to work on