numpy.eye

numpy.eye(N, M=None, k=0, dtype=<class 'float'>, order='C') [source]

Return a 2-D array with ones on the diagonal and zeros elsewhere.

Parameters:

N : int Number of rows in the output. M : int, optional Number of columns in the output. If None, defaults to N. k : int, optional Index of the diagonal: 0 (the default) refers to the main diagonal, a positive value refers to an upper diagonal, and a negative value to a lower diagonal. dtype : data-type, optional Data-type of the returned array. order : {‘C’, ‘F’}, optional Whether the output should be stored in row-major (C-style) or column-major (Fortran-style) order in memory. New in version 1.14.0.

Returns:

I : ndarray of shape (N,M) An array where all elements are equal to zero, except for the k-th diagonal, whose values are equal to one.

See also

identity

(almost) equivalent function

diag

diagonal 2-D array from a 1-D array specified by the user.

Examples

>>> np.eye(2, dtype=int)
array([[1, 0],
       [0, 1]])
>>> np.eye(3, k=1)
array([[0.,  1.,  0.],
       [0.,  0.,  1.],
       [0.,  0.,  0.]])