scipy.linalg.triu

scipy.linalg.triu(m, k=0)

Make a copy of a matrix with elements below the k-th diagonal zeroed.

Parameters :

m : array_like

Matrix whose elements to return

k : int, optional

Diagonal below which to zero elements. k == 0 is the main diagonal, k < 0 subdiagonal and k > 0 superdiagonal.

Returns :

triu : ndarray

Return matrix with zeroed elements below the k-th diagonal and has same shape and type as m.

Examples

>>> from scipy.linalg import triu
>>> triu([[1,2,3],[4,5,6],[7,8,9],[10,11,12]], -1)
array([[ 1,  2,  3],
       [ 4,  5,  6],
       [ 0,  8,  9],
       [ 0,  0, 12]])