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# 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

  `shape` | Get shape of a matrix.
  `nnz` | Number of stored values, including explicit zeros.

  dtype | (dtype) Data type 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) | Cast the matrix elements to a specified type.
  `ceil`() | Element-wise ceil.
  `conj`() | Element-wise complex conjugation.
  `conjugate`() | Element-wise complex conjugation.
  `copy`() | Returns a copy of this matrix.
  `count_nonzero`() | Number of non-zero entries, equivalent to
  `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`() | Return the Hermitian transpose of this matrix.
  `get_shape`() | Get shape of a matrix.
  `getcol`(j) | Returns a copy of column j of the matrix, as an (m x 1) sparse matrix (column vector).
  `getformat`() | Format of a matrix representation as a string.
  `getmaxprint`() | Maximum number of elements to display when printed.
  `getnnz`([axis]) | Number of stored values, including explicit zeros.
  `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) | Element-wise maximum between this and another matrix.
  `mean`([axis, dtype, out]) | Compute the arithmetic mean along the specified axis.
  `minimum`(other) | Element-wise minimum between this and another matrix.
  `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[, order]) | Gives a new shape to a sparse matrix without changing its data.
  `rint`() | Element-wise rint.
  `set_shape`(shape) | See `reshape`.
  `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, dtype, out]) | Sum the matrix elements over a given axis.
  `tan`() | Element-wise tan.
  `tanh`() | Element-wise tanh.
  `toarray`([order, out]) | Return a dense ndarray representation of this matrix.
  `tobsr`([blocksize, copy]) | Convert this matrix to Block Sparse Row format.
  `tocoo`([copy]) | Convert this matrix to COOrdinate format.
  `tocsc`([copy]) | Convert this matrix to Compressed Sparse Column format.
  `tocsr`([copy]) | Convert this matrix to Compressed Sparse Row format.
  `todense`([order, out]) | Return a dense matrix representation of this matrix.
  `todia`([copy]) | Convert this matrix to sparse DIAgonal format.
  `todok`([copy]) | Convert this matrix to Dictionary Of Keys format.
  `tolil`([copy]) | Convert this matrix to LInked List format.
  `transpose`([axes, copy]) | Reverses the dimensions of the sparse matrix.
  `trunc`() | Element-wise trunc.