On Sat, Nov 12, 2011 at 3:36 AM, Geoffrey Zhu <zyzhu2...@gmail.com> wrote: > Hi, > > I am playing with multiple ways to speed up the following expression > (it is in the inner loop): > > > C[1:(M - 1)]=(a * C[2:] + b * C[1:(M-1)] + c * C[:(M-2)]) > > where C is an array of about 200-300 elements, M=len(C), a, b, c are scalars. > > I played with numexpr, but it was way slower than directly using > numpy. It would be nice if I could create a Mx3 matrix without copying > memory and so I can use dot() to calculate the whole thing. > > Can anyone help with giving some advices to make this faster?
looks like a np.convolve(C, [a,b,c]) to me except for the boundary conditions. Josef > > Thanks, > G > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion > _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion