Yes I was just coming to post. This is an error in sympy if you use the variable name 'N'
so do this: (1 + x).subs(dict(x=1, y=2, N=3)) which complains about N being a function, so I imagine the fix is to import the N function in the subs namespace with an underscore... maybe this is already fixed. I am using 0.6.4 Gabriel On Aug 6, 2:24 pm, Ondrej Certik <[email protected]> wrote: > On Thu, Aug 6, 2009 at 12:09 PM, Gabriel<[email protected]> wrote: > > > I would like to do substitution for a set of symbols into an > > expression where not all the symbols may be defined. > > > something like > > > (1 + x).subs(dict(x=1, y=2)) > > > which raises a cryptic error since y is not in the expression. (the > > problem this is for is that I am making a jacobian then substituting > > in the equilibrium values, but I don't want to check all n**2 entries > > to see which symbols have dropped out). > > > Any tips, pointers? > > Could you please post the full script? Your line works for me: > > In [1]: (1 + x).subs(dict(x=1, y=2)) > Out[1]: 2 > > Ondrej --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sympy?hl=en -~----------~----~----~----~------~----~------~--~---
