.. _spmatrix_api:

==================================================== Sparse Matrix Legacy Interface (:mod:scipy.sparse)

.. currentmodule:: scipy.sparse

SciPy 2-D sparse matrix interface for numeric data.

.. warning::

The SciPy sparse package is switching to an array interface, compatible with NumPy arrays, from the older numpy.matrix interface. We recommend that you use the array objects (csr_array, coo_array, etc.).

When using the array interface, please note that:

• x * y performs element-wise multiplication (just like NumPy arrays). To make code work with both arrays and matrices, use x @ y for matrix multiplication.
• Operations, like sum, produce np.matrix for spmatrix while they produce np.array for sparray. Multiplication of np.matrix and np.array differ in the same way as between spmatrix and sparray.
• Sparse arrays use array style slicing operations, returning scalars, or 1D or 2D sparse arrays according to the numpy standards for indexing. If you need always 2D results, use an appropriate index with sparse arrays. For example, A[:, i, None] or A[:, [i]].

The construction utilities (eye, kron, random, diags, etc.) have appropriate replacements (see :ref:sparse-construction-functions).

For more information see :ref:Migration from spmatrix to sparray <migration_to_sparray>.

Sparse matrix classes

.. autosummary:: :toctree: generated/

bsr_matrix - Block Sparse Row matrix coo_matrix - A sparse matrix in COOrdinate format csc_matrix - Compressed Sparse Column matrix csr_matrix - Compressed Sparse Row matrix dia_matrix - Sparse matrix with DIAgonal storage dok_matrix - Dictionary Of Keys based sparse matrix lil_matrix - Row-based list of lists sparse matrix spmatrix - Sparse matrix base class

Building sparse matrices

.. autosummary:: :toctree: generated/

eye - Sparse MxN matrix whose k-th diagonal is all ones identity - Identity matrix in sparse matrix format diags - Return a sparse matrix from diagonals spdiags - Return a sparse matrix from diagonals bmat - Build a sparse matrix from sparse sub-blocks random - Random values in a given shape matrix rand - Random values in a given shape matrix (old interface)

To combine matrices use the same functions as for :ref:combining-arrays.

Identifying sparse matrices

.. autosummary:: :toctree: generated/

issparse isspmatrix isspmatrix_csc isspmatrix_csr isspmatrix_bsr isspmatrix_lil isspmatrix_dok isspmatrix_coo isspmatrix_dia