[Tutor] Array filling

[Eike Welk]

On Thursday 03 July 2008 15:53, Brain Stormer wrote:
> I am using numpy to create an array then filling some of the values
> using a for loop, I was wondering if there is way to easily fill
> the values without iterating through sort of like
> "array.fill[start:stop,start:stop]"?  The reason for my question
> is, in some cases, I might have to fill hundreds (within a
> 10,000x10,000 matrix) of values and I am not sure if iteration is
> the right way to go.

You can do it this way:

>>> from numpy import *
>>> m = zeros((5,5), int)
>>> m[1:4, 1:4] = 1
>>> m
array([[0, 0, 0, 0, 0],
       [0, 1, 1, 1, 0],
       [0, 1, 1, 1, 0],
       [0, 1, 1, 1, 0],
       [0, 0, 0, 0, 0]])

HTH, Eike.