cunumeric.trace#

cunumeric.trace(a: ndarray, offset: int = 0, axis1: int | None = None, axis2: int | None = None, dtype: dtype[Any] | None = None, out: ndarray | None = None) → ndarray#

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.

Parameters:

a (array_like) – Input array, from which the diagonals are taken.
offset (int, optional) – Offset of the diagonal from the main diagonal. Can be both positive and negative. Defaults to 0.
axis1 (int, optional) – Axes to be used as the first and second axis of the 2-D sub-arrays from which the diagonals should be taken. Defaults are the first two axes of a.
axis2 (int, optional) – Axes to be used as the first and second axis of the 2-D sub-arrays from which the diagonals should be taken. Defaults are the first two axes of a.
dtype (data-type, optional) – Determines the data-type of the returned array and of the accumulator where the elements are summed. If dtype has the value None and a is of integer type of precision less than the default integer precision, then the default integer precision is used. Otherwise, the precision is the same as that of a.
out (ndarray, optional) – Array into which the output is placed. Its type is preserved and it must be of the right shape to hold the output.

Returns:

sum_along_diagonals – If a is 2-D, the sum along the diagonal is returned. If a has larger dimensions, then an array of sums along diagonals is returned.

Return type:

ndarray

Raises:

ValueError – If the dimension of a is less than 2.