strides

Therefore the number of strides for the vertical direction (axis-0) is 3*4 = 12 bytes. Note that going from a [0, 2] - a [1, 0], and in general from the last item of the i-th row to the first item of the (i+1)-th row, is also 4 bytes because the array a is stored in the row-major order. Here strides [1] is a multiple of the item-size.