On Sat, Nov 12, 2011 at 9:44 AM, [email protected] <[email protected]> wrote: > Hi, > > I was bashing lambdify lately, but it seems this function is smarter than > me. I'll skip the details about what I incorrectly thought the problem was > and present the real problem. > > This works great: > > lambdify(x, Integral(y, (y, 0, x))) > > _(2) ---> Integral(y, (y, 0, 2)) > > float(_) ---> the right numeric answer > > This also works great: > > lambdify(x, Integral(sqrt(y), (y, 0, x)), modules='sympy') > > _(2) ---> Integral(sqrt(y), (y, 0, 2)) > > float(_) ---> the right numeric answer > > This does not work because sqrt is translated to the numpy function > > lambdify(x, Integral(sqrt(y), (y, 0, x))) > > _(2) ---> ValueError: Symbolic value, can't compute > > Any ideas? That is not a bug a priori but it should at least be very well > documented.
That looks like a bug to me. It shouldn't use the numpy sqrt unless you pass "numpy" as the third argument. Aaron Meurer > > > P.S. And the docstring should not tell people that lambdify is for numeric > calculation when it does not return floats. > P.P.S The fact that lambdify can not do Sums, stuff from the physics module, > etc is another problem. > > -- > 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. > -- 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.
