scipy.sparse.spdiags

scipy.sparse.spdiags(data, diags, m, n, format=None)

Return a sparse matrix from diagonals.

Parameters :

data : array_like

matrix diagonals stored row-wise

diags : diagonals to set

• k = 0 the main diagonal
• k > 0 the k-th upper diagonal
• k < 0 the k-th lower diagonal

m, n : int

shape of the result

format : format of the result (e.g. “csr”)

By default (format=None) an appropriate sparse matrix format is returned. This choice is subject to change.

See also

dia_matrix

the sparse DIAgonal format.

Examples

>>> data = array([[1,2,3,4],[1,2,3,4],[1,2,3,4]])
>>> diags = array([0,-1,2])
>>> spdiags(data, diags, 4, 4).todense()
matrix([[1, 0, 3, 0],
        [1, 2, 0, 4],
        [0, 2, 3, 0],
        [0, 0, 3, 4]])