python - How to get euclidean distance on a 3x3x3 array in numpy -


say have (3,3,3) array this. 

array([[[1, 1, 1],         [1, 1, 1],         [0, 0, 0]],         [[2, 2, 2],         [2, 2, 2],         [2, 2, 2]],         [[3, 3, 3],         [3, 3, 3],         [1, 1, 1]]])

how 9 values corresponding euclidean distance between each vector of 3 values , zeroth values?

such doing numpy.linalg.norm([1,1,1] - [1,1,1]) 2 times, , doing norm([0,0,0] - [0,0,0]), , norm([2,2,2] - [1,1,1]) 2 times, norm([2,2,2] - [0,0,0]), norm([3,3,3] - [1,1,1]) 2 times, , norm([1,1,1] - [0,0,0]).

any ways vectorize this? want store distances in (3,3,1) matrix.

the result be:

array([[[0. ],         [0. ],         [0. ]],         [[1.73],         [1.73],         [3.46]]         [[3.46],         [3.46],         [1.73]]])

keepdims argument added in numpy 1.7, can use keep sum axis:

np.sum((x - [1, 1, 1])**2, axis=-1, keepdims=true)**0.5

the result is:

[[[ 0.        ]   [ 0.        ]   [ 0.        ]]   [[ 1.73205081]   [ 1.73205081]   [ 1.73205081]]   [[ 3.46410162]   [ 3.46410162]   [ 0.        ]]]

edit

np.sum((x - x[0])**2, axis=-1, keepdims=true)**0.5

the result is:

array([[[ 0.        ],         [ 0.        ],         [ 0.        ]],         [[ 1.73205081],         [ 1.73205081],         [ 3.46410162]],         [[ 3.46410162],         [ 3.46410162],         [ 1.73205081]]])

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