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bundles / scipy 1.18.0 / scipy / sparse / _construct / spdiags

function

scipy.sparse._construct:spdiags

source: /scipy/sparse/_construct.py:255

Signature

def spdiags(data, diags, m = None, n = None, format = None)

Summary

Return a sparse matrix from diagonals.

Extended Summary

Parameters

data : array_like

Matrix diagonals stored row-wise

diags : sequence of int or an int

Diagonals to set:

  • k = 0 the main diagonal

  • k > 0 the kth upper diagonal

  • k < 0 the kth lower diagonal

m, n : int, tuple, optional

Shape of the result. If n is None and m is a given tuple, the shape is this tuple. If omitted, the matrix is square and its shape is len(data[0]).

format : str, optional

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

Returns

new_matrix : sparse matrix

dia_matrix format with values in data on diagonals from diags.

Notes

This function can be replaced by an equivalent call to dia_matrix as 

dia_matrix((data, diags), shape=(m, n)).asformat(format)

Examples

import numpy as np
from scipy.sparse import spdiags
data = np.array([[1, 2, 3, 4], [1, 2, 3, 4], [1, 2, 3, 4]])
diags = np.array([0, -1, 2])
spdiags(data, diags, 4, 4).toarray()
✓
array([[1, 0, 3, 0],
       [1, 2, 0, 4],
       [0, 2, 3, 0],
       [0, 0, 3, 4]])

See also

dia_matrix

the sparse DIAgonal format.

diags

matrix version of diags_array.

diags_array

more convenient form of this function.

Aliases

  • scipy.sparse.spdiags