numpy.diagflat — NumPy v1.11 Manual (original) (raw)

numpy.diagflat(v, k=0)[source]

Create a two-dimensional array with the flattened input as a diagonal.

Parameters: v : array_like Input data, which is flattened and set as the _k_-th diagonal of the output. k : int, optional Diagonal to set; 0, the default, corresponds to the “main” diagonal, a positive (negative) k giving the number of the diagonal above (below) the main.
Returns: out : ndarray The 2-D output array.

See also

diag

MATLAB work-alike for 1-D and 2-D arrays.

diagonal

Return specified diagonals.

trace

Sum along diagonals.

Examples

np.diagflat([[1,2], [3,4]]) array([[1, 0, 0, 0], [0, 2, 0, 0], [0, 0, 3, 0], [0, 0, 0, 4]])

np.diagflat([1,2], 1) array([[0, 1, 0], [0, 0, 2], [0, 0, 0]])