numpy.tri¶
-
numpy.
tri
(N, M=None, k=0, dtype=<class 'float'>)[source]¶ An array with ones at and below the given diagonal and zeros elsewhere.
Parameters: N : int
Number of rows in the array.
M : int, optional
Number of columns in the array. By default, M is taken equal to N.
k : int, optional
The sub-diagonal at and below which the array is filled. k = 0 is the main diagonal, while k < 0 is below it, and k > 0 is above. The default is 0.
dtype : dtype, optional
Data type of the returned array. The default is float.
Returns: tri : ndarray of shape (N, M)
Array with its lower triangle filled with ones and zero elsewhere; in other words
T[i,j] == 1
fori <= j + k
, 0 otherwise.Examples
>>> np.tri(3, 5, 2, dtype=int) array([[1, 1, 1, 0, 0], [1, 1, 1, 1, 0], [1, 1, 1, 1, 1]])
>>> np.tri(3, 5, -1) array([[ 0., 0., 0., 0., 0.], [ 1., 0., 0., 0., 0.], [ 1., 1., 0., 0., 0.]])