Return the sum along diagonals of the array.
If a is 2-D, the sum along its diagonal with the given offset is returned, i.e., the sum of elements a[i,i+offset] for all i.
If a has more than two dimensions, then the axes specified by axis1 and axis2 are used to determine the 2-D sub-arrays whose traces are returned. The shape of the resulting array is the same as that of a with axis1 and axis2 removed.
a : array_like
offset : int, optional
axis1, axis2 : int, optional
dtype : dtype, optional
out : ndarray, optional
sum_along_diagonals : ndarray
>>> np.trace(np.eye(3)) 3.0 >>> a = np.arange(8).reshape((2,2,2)) >>> np.trace(a) array([6, 8])
>>> a = np.arange(24).reshape((2,2,2,3)) >>> np.trace(a).shape (2, 3)