I would like to compute the product


where $E$, $F_i$, and $r_i$ represent arbitrary numbers whose notation makes sense in the general problem I am working on.

When I simply copy and paste the LaTex expression into Mathematica, I get some weird stuff which clearly is not the product.

What I am doing wrong?


2 Answers 2

str = "(e*s+r_{13})(F_{13}s)(F_{3}s+r_{3})(F_{2}s+r_{2})(F_{12}s+r_{12})(F_{1}s+r_{1})(F_{23}s+r_{23})";
ToExpression[str, TeXForm]

(*    s Subscript[F, 13] (s Subscript[F, 1] + Subscript[r, 1])
      (s Subscript[F, 2] + Subscript[r, 2]) (s Subscript[F, 3] + Subscript[r, 3])
      (s Subscript[F, 12] + Subscript[r, 12]) (e s + Subscript[r, 13])
      (s Subscript[F, 23] + Subscript[r, 23])                     *)
  • $\begingroup$ Can I further ask how to ask mathematica to only show the coefficients of s^3 terms in the product? $\endgroup$ Jan 9, 2021 at 14:35
  • $\begingroup$ Yes, with Coefficient[%, s^3]. $\endgroup$
    – Roman
    Jan 9, 2021 at 14:57
  • $\begingroup$ Please note that I've modified the first term from Es to e*s because Es is a single symbol. $\endgroup$
    – Roman
    Jan 9, 2021 at 15:02

You can remove the space from the pasted-in LaTeX expression so your $Es$, which was interpreted as $E s$, goes back to being $Es$.

Expression as pasted in:


which evaluates to:


Edit the expression to:


so it now evaluates to:


which is what I presume you want.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.