Attributes

dtype : dtype

Data type of the matrix

shape : 2-tuple

Shape of the matrix

ndim : int

Number of dimensions (this is always 2)

nnz :

Number of nonzero elements

This is an efficient structure for constructing sparse matrices incrementally.

This can be instantiated in several ways:

dok_matrix(D)

with a dense matrix, D

dok_matrix(S)

with a sparse matrix, S

dok_matrix((M,N), [dtype])

create the matrix with initial shape (M,N) dtype is optional, defaulting to dtype='d'

Notes

Sparse matrices can be used in arithmetic operations: they support addition, subtraction, multiplication, division, and matrix power.

Allows for efficient O(1) access of individual elements. Duplicates are not allowed. Can be efficiently converted to a coo_matrix once constructed.

Dictionary Of Keys based sparse matrix.

Examples

>>> import numpy as np
... from scipy.sparse import dok_matrix
... S = dok_matrix((5, 5), dtype=np.float32)
... for i in range(5):
...     for j in range(5):
...         S[i, j] = i + j    # Update element

See :

Back References

The following pages refer to to this document either explicitly or contain code examples using this.

scipy.sparse._dok.dok_matrix._update scipy.sparse._dok.isspmatrix_dok scipy.sparse._dok.dok_matrix

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GitHub : /scipy/sparse/_dok.py#23
type: <class 'type'>
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