I have an array to be used for indexing. It is 2d, where the rows are all the
permutations of some numbers. So:
array([[-2, -2, -2],
[-2, -2, -1],
[-2, -2, 0],
[-2, -2, 1],
[-2, -2, 2],
...
[ 2, 1, 2],
[ 2, 2, -2],
[ 2, 2, -1],
[ 2, 2, 0],
[ 2, 2, 1],
[ 2, 2, 2]])
Here the array is 125x3
I want to select all the rows of the array in which all the 3 elements are
equal, so I can remove them. So for example, the 1st and last row.