Iterate with binary structure over numpy array to get cell sums
- by Curlew
In the package scipy there is the function to define a binary structure (such as a taxicab (2,1) or a chessboard (2,2)).
import numpy
from scipy import ndimage
a = numpy.zeros((6,6), dtype=numpy.int)
a[1:5, 1:5] = 1;a[3,3] = 0 ; a[2,2] = 2
s = ndimage.generate_binary_structure(2,2) # Binary structure
#.... Calculate Sum of
result_array = numpy.zeros_like(a)
What i want is to iterate over all cells of this array with the given structure s. Then i want to append a function to the current cell value indexed in a empty array (example function sum), which uses the values of all cells in the binary structure.
For example:
array([[0, 0, 0, 0, 0, 0],
[0, 1, 1, 1, 1, 0],
[0, 1, 2, 1, 1, 0],
[0, 1, 1, 0, 1, 0],
[0, 1, 1, 1, 1, 0],
[0, 0, 0, 0, 0, 0]])
# The array a. The value in cell 1,2 is currently one. Given the structure s and an example function such as sum the value in the resulting array (result_array) becomes 7 (or 6 if the current cell value is excluded).
Someone got an idea?
