从 numpy 数组的每个子数组中查找最大值

Question

I have an array:

x = array([[[ 0,  1,  2],
        [ 6,  7,  8],
        [12, 13, 14]],

       [[ 3,  4,  5],
        [ 9, 10, 11],
        [15, 16, 17]],

       [[18, 19, 20],
        [24, 25, 26],
        [30, 31, 32]],

       [[21, 22, 23],
        [27, 28, 29],
        [33, 34, 35]]])

I want to find the max values of each subarrays and store them in lets say an array. So the output should be:

output = array([14,17,32,35])

Now, one can easily do this using a loop, however, I want to avoid it. np.max(x) is giving output 35, that is the max value of the entire array. np.max(axis) also is not working (I am not very sure it would work, but I tried anyway) Anyone, can you help?

Answer 1

Simply:

[max(j) for j in [max(i) for i in x.tolist()]]

Output:

[14, 17, 32, 35]

Answer 2

You can use np.max for axis=1 twice

x.max(axis=1).max(axis=1)   

OUTPUT

Out[203]: array([14, 17, 32, 35])