This is part of my continuing my work on making sympy capable of generating code for evaluating matrix functions. So far the codeprinters and codegen is done(ish); all that's left is autowrap.
Questions: 1. Should functions created by autowrap create matrices that would be in-out parameters in the resulting C code? Suppose the C header is: void func(double a, double b, double c, double mat[3][4]) Should `mat` be created in the wrapper code, so that the python function header is func(a, b, c)? The performance benefits vs pythonic-ness really have to do with the nature of the calculations. If `mat` is small, but has elements with lots of operations (as seen in sympy.physics.mechanics) then the performance hit is neglible. In contrast, if `mat` is big, but has simple elements, the hit is relatively large. Perhaps a kwarg? Or maybe if autowrap is passed (Eq(x, mat)) it will set an input matrix `x` to `mat`, otherwise it will return matrix `mat`? 2. What should `ufuncify` do with matrices? Jason messaged me earlier with a thought on this, I'll just paste his use case here as it explains it fairly well. A very common use case that I'm finding in all my dynamics work is to > evaluate matrices in a tight loop for millions of iterations. It would be > cool to pass in a sympy matrix and generate a function that would return a > 3D numpy array when you evaluate the function with equal length arrays (or > scalars) as args. For example: > > expr = Matrix([[a, b], [c, d]]) > f = ufuncify((a, b, c, d), expr) > out = f(rand(1e6), rand(1e6), rand(1e6), 1.5) > out.shape == (1e6, 4, 4) This kind of broadcasting would be doable (but maybe complicated? I'm not sure.). The big question is, does this kind of behavior for `ufuncify` make sense? -- 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 http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/771f1dfa-0a80-49ed-9a88-76a690f4aa96%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
