Re: [Numpy-discussion] differencing numarray arrays.

Mike Zingale wrote:

Hi, I am trying to efficiently compute a difference of two 2-d flux arrays, as arises quite commonly in finite-difference/finite-volume methods. Ex:

a = arange(64) a.shape = (8,8)

I want to do create a new array, b, of shape such that

b[i,j] = a[i,j] - a[i-1,j]

for 1 <= i < 8 0 <= i < 8

Try b = a[1:] - a[:-1] -- Robert Kern rkern@ucsd.edu "In the fields of hell where the grass grows high Are the graves of dreams allowed to die." -- Richard Harter