[SciPy-user] maximum_filter1d size parameter

[Rick Giuly]

Hello All,

It seems I'm not understanding the "size" parameter for 
maximum_filter1d. The documentation says size is the "length along which 
to calculate 1D maximum"

Starting with this array:
 >>> a
array([[1, 2, 3],
        [4, 1, 1],
        [1, 6, 7]])


Because there are 3 rows in the matrix, it seems to me that with size 
set to 3, the result of the filter would be:
array([[4, 6, 7],
        [4, 6, 7],
        [4, 6, 7]])


But the result is this:

 >>> maximum_filter1d(a, 3, axis=0)
array([[4, 2, 3],
        [4, 6, 7],
        [4, 6, 7]])


I don't see why.

Any help is appreciated.

-rick