The problem of "python functions evaluate immediately sympy functions don't" is obvious when one tries to plot/lambdify something that contains both Expr and some numerical routine. Try to imagine a way to plot nsolve(..)*some_Expr for example.
On 10 January 2012 17:30, [email protected] < [email protected]> wrote: > Or more likely it's better to use implemented_function that is imported > from utilities.lambdify? > It seems to me that implemented_function is quite important if one wants > for example to have complicated numerical routines accessible as sympy > expressions. In my opinion it's actually important enough to be mentioned > in the tutorial/pitfalls. Because defining a function to be used in sympy > is actually not as simple as defining a python function (python functions > evaluate immediately, sympy functions do not). > > Another question that I need help with is what is Lambda used for. Is > there something that Lambda does and implemented_function does not? > > > On 10 January 2012 16:39, [email protected] < > [email protected]> wrote: > >> How can I represent an unevaluated call to nsolve as a sympy expression? >> Is Lambda the best (and standard) solution? >> >> The expression I want to represent looks like nsolve(x-tanh(x-h),[x],0). >> The free symbol is h. It's in the context of plotting phase transition >> diagrams. >> > > -- 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.
