scipy.sparse.dia_matrix

class scipy.sparse.dia_matrix(arg1, shape=None, dtype=None, copy=False)

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 diagonal offsets[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

arcsin()	Element-wise arcsin.
arcsinh()	Element-wise arcsinh.
arctan()	Element-wise arctan.
arctanh()	Element-wise arctanh.
asformat(format)	Return this matrix in a given sparse format
asfptype()	Upcast matrix to a floating point format (if necessary)
astype(t)
ceil()	Element-wise ceil.
conj()
conjugate()
copy()
deg2rad()	Element-wise deg2rad.
diagonal()	Returns the main diagonal of the matrix
dot(other)	Ordinary dot product ..
expm1()	Element-wise expm1.
floor()	Element-wise floor.
getH()
get_shape()
getcol(j)	Returns a copy of column j of the matrix, as an (m x 1) sparse matrix (column vector).
getformat()
getmaxprint()
getnnz()	number of nonzero values
getrow(i)	Returns a copy of row i of the matrix, as a (1 x n) sparse matrix (row vector).
log1p()	Element-wise log1p.
maximum(other)
mean([axis])	Average the matrix over the given axis.
minimum(other)
multiply(other)	Point-wise multiplication by another matrix
nonzero()	nonzero indices
power(n[, dtype])	This function performs element-wise power.
rad2deg()	Element-wise rad2deg.
reshape(shape)
rint()	Element-wise rint.
set_shape(shape)
setdiag(values[, k])	Set diagonal or off-diagonal elements of the array.
sign()	Element-wise sign.
sin()	Element-wise sin.
sinh()	Element-wise sinh.
sqrt()	Element-wise sqrt.
sum([axis])	Sum the matrix over the given axis.
tan()	Element-wise tan.
tanh()	Element-wise tanh.
toarray([order, out])	Return a dense ndarray representation of this matrix.
tobsr([blocksize])
tocoo()
tocsc()
tocsr()
todense([order, out])	Return a dense matrix representation of this matrix.
todia([copy])
todok()
tolil()
transpose()
trunc()	Element-wise trunc.