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

```>>> from scipy.sparse import *
>>> from scipy import *
>>> dia_matrix( (3,4), dtype=int8).todense()
matrix([[0, 0, 0, 0],
[0, 0, 0, 0],
[0, 0, 0, 0]], dtype=int8)
```
```>>> data = array([[1,2,3,4]]).repeat(3,axis=0)
>>> offsets = array([0,-1,2])
>>> dia_matrix( (data,offsets), shape=(4,4)).todense()
matrix([[1, 0, 3, 0],
[1, 2, 0, 4],
[0, 2, 3, 0],
[0, 0, 3, 4]])
```

Attributes

 dtype shape ndim int(x[, base]) -> integer nnz number of nonzero values
 data DIA format data array of the matrix offsets DIA format offset array of the matrix

Methods

 asformat(format) Return this matrix in a given sparse format asfptype() Upcast matrix to a floating point format (if necessary) astype(t) conj() conjugate() copy() diagonal() Returns the main diagonal of the matrix dot(other) getH() get_shape() getcol(j) Returns a copy of column j of the matrix, as an (m x 1) sparse getformat() getmaxprint() getnnz() number of nonzero values getrow(i) Returns a copy of row i of the matrix, as a (1 x n) sparse mean([axis]) Average the matrix over the given axis. multiply(other) Point-wise multiplication by another matrix nonzero() nonzero indices reshape(shape) set_shape(shape) setdiag(values[, k]) Fills the diagonal elements {a_ii} with the values from the given sequence. sum([axis]) Sum the matrix over the given axis. toarray() tobsr([blocksize]) tocoo() tocsc() tocsr() todense() todia([copy]) todok() tolil() transpose()

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