Working with arrays can be a bit confusing to begin with. Here’s a quick and dirty array indexing guide to make sure you never get confused.
test = np.array([[ 0, 1, 2, 3, 4], [ 5, 6, 7, 8, 9], [10, 11, 12, 13, 14]])
Select the third row (row #2):
print test[2] >> [10 11 12 13 14]
Select row 0 and 1:
print test[:2] >> [[0 1 2 3 4] [5 6 7 8 9]]
Select the last row:
print test[-1] >> [10 11 12 13 14]
Select column 2:
print test[:,2] >> [ 2 7 12]
Select elements 0 and 1 in column 2:
print test [0:2, 2] >> [2 7]
Filed under: python | Tagged: array, ndarray, numpy, python | Leave a comment »