Hi, I think there is an error when `lambdifying` the sinc function, at least using 'numpy'. Sympy defines the sinc function as unnormalized; i.e sin(x)/x, while numpy defines it as normalized sin(pi.x)/(pi.x). So, the evaluation for [-1, 0, 1] is not the same:
>>> import sympy as sp >>> f = sp.lambdify(x, sp.sinc(x), "numpy") >>> f([-1, 0, 1]) array([ 3.89817183e-17, 1.00000000e+00, 3.89817183e-17]) BUT >>> s = sp.sinc(x) >>> s.subs(x, -1).evalf() 0.841470984807897 >>> s.subs(x, 1).evalf() 0.841470984807897 I'm used to signal processing so I would prefer the normalized definition. In any case, the functions must be 'aligned'. Regards, José Parera -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/c00d4d7b-8de9-4cb0-9357-019cfafccfab%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
