On Thu, Nov 19, 2009 at 7:45 PM, Alex Raichev <tortoise.s...@gmail.com> wrote: > Thanks for the workaround, William. I was thinking the same thing as > a temporary fix but am having difficulties with that approach. > > Here's my situation. I have a big symbolic expression E involving > lots of derivatives. I want to substitute the derivatives with other > symbolic expressions, and the substitutions are stored in a big > dictionary D. Presently E.subs(D) does not work in Sage. > > I tried a keyword substitution instead, but got the error > 'SyntaxError: keyword can't be an expression (<ipython console>, line > 1)' > > Another approach is to convert E and the keys of D to strings, perform > the substitution as strings, and then convert E back to a symbolic > expression. I'm trying this now but am getting stuck with the string > substitution step... > > If anyone out there can think of a simpler temporary workaround, > please let me know.
If you're using strings, you might find this useful: sage: sage.misc.multireplace.multiple_replace? William -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
