scipy.sparse.dia_matrix¶
-
class
scipy.sparse.
dia_matrix
(arg1, shape=None, dtype=None, copy=False)[source]¶ Sparse matrix with DIAgonal storage
- This can be instantiated in several ways:
- dia_matrix(D)
- with a dense matrix
- dia_matrix(S)
- with another sparse matrix S (equivalent to S.todia())
- dia_matrix((M, N), [dtype])
- to construct an empty matrix with shape (M, N), dtype is optional, defaulting to dtype=’d’.
- dia_matrix((data, offsets), shape=(M, N))
- where the
data[k,:]
stores the diagonal entries for diagonaloffsets[k]
(See example below)
Notes
Sparse matrices can be used in arithmetic operations: they support addition, subtraction, multiplication, division, and matrix power.
Examples
>>> import numpy as np >>> from scipy.sparse import dia_matrix >>> dia_matrix((3, 4), dtype=np.int8).toarray() array([[0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0]], dtype=int8)
>>> data = np.array([[1, 2, 3, 4]]).repeat(3, axis=0) >>> offsets = np.array([0, -1, 2]) >>> dia_matrix((data, offsets), shape=(4, 4)).toarray() array([[1, 0, 3, 0], [1, 2, 0, 4], [0, 2, 3, 0], [0, 0, 3, 4]])
Attributes
nnz
number of nonzero values dtype (dtype) Data type of the matrix shape (2-tuple) Shape of the matrix ndim (int) Number of dimensions (this is always 2) data DIA format data array of the matrix offsets DIA format offset array of the matrix Methods