I have a numpy array of shape (4, 7) like this:
array([[ 1, 4, 5, 7, 8, 6, 7]
[ 2, 23, 2, 4, 8, 94, 2],
[ 1, 5, 6, 7, 10, 15, 20],
[ 3, 9, 2, 7, 6, 5, 4]])
I would like to get the index of the highest element, i.e. 94, in a form like: first row fifth column. Thus the output should be a numpy array ([1,5]) (matlab-style).
You get the index of the maximum index using arr.argmax() but to get the actual row and column you must use np.unravel_index as below:
import numpy as np
arr = np.array([[ 1, 4, 5, 7, 8, 6, 7],
[ 2, 23, 2, 4, 8, 94, 2],
[ 1, 5, 6, 7, 10, 15, 20],
[ 3, 9, 2, 7, 6, 5, 4]])
maximum = np.unravel_index(arr.argmax(), arr.shape)
print(maximum)
# (1, 5)
You have to use np.unravel_index as by default np.argmax will return the index from a flattened array (which in your case would be index 12).