pymc.math.extract_diag#

pymc.math.extract_diag = <pytensor.tensor.basic.ExtractDiag object>#

Return specified diagonals.

If x is 2-D, returns the diagonal of x with the given offset, i.e., the collection of elements of the form x[i, i+offset]. If x has more than two dimensions, then the axes specified by axis1 and axis2 are used to determine the 2-D sub-array whose diagonal is returned. The shape of the resulting array can be determined by removing axis1 and axis2 and appending an index to the right equal to the size of the resulting diagonals.

Parameters

x: A tensor variable with x.ndim >= 2.
offset: Offset of the diagonal from the main diagonal.: Can be positive or negative. Defaults to main diagonal (0).
axis1: Axis to be used as the first axis of the 2-D: sub-arrays from which the diagonals should be taken. Defaults to first axis (0).
axis2: Axis to be used as the second axis of the 2-D: sub-arrays from which the diagonals should be taken. Defaults to second axis (1).

Returns

array_of_diagonals:: If x is 2-D, a 1-D array of the same type as a containing the diagonal is returned. If the dimension of x is greater than two, then an array of diagonals is returned, “packed” from left-most dimension to right-most (e.g., if x is 3-D, then the diagonals are “packed” along rows).

Raises

ValueError: If the dimension of x is less than 2.