3RNN/Lib/site-packages/scipy/sparse/_base.py
2024-05-26 19:49:15 +02:00

1569 lines
51 KiB
Python

"""Base class for sparse matrices"""
from warnings import warn
import numpy as np
from scipy._lib._util import VisibleDeprecationWarning
from ._sputils import (asmatrix, check_reshape_kwargs, check_shape,
get_sum_dtype, isdense, isscalarlike,
matrix, validateaxis,)
from ._matrix import spmatrix
__all__ = ['isspmatrix', 'issparse', 'sparray',
'SparseWarning', 'SparseEfficiencyWarning']
class SparseWarning(Warning):
pass
class SparseFormatWarning(SparseWarning):
pass
class SparseEfficiencyWarning(SparseWarning):
pass
# The formats that we might potentially understand.
_formats = {'csc': [0, "Compressed Sparse Column"],
'csr': [1, "Compressed Sparse Row"],
'dok': [2, "Dictionary Of Keys"],
'lil': [3, "List of Lists"],
'dod': [4, "Dictionary of Dictionaries"],
'sss': [5, "Symmetric Sparse Skyline"],
'coo': [6, "COOrdinate"],
'lba': [7, "Linpack BAnded"],
'egd': [8, "Ellpack-itpack Generalized Diagonal"],
'dia': [9, "DIAgonal"],
'bsr': [10, "Block Sparse Row"],
'msr': [11, "Modified compressed Sparse Row"],
'bsc': [12, "Block Sparse Column"],
'msc': [13, "Modified compressed Sparse Column"],
'ssk': [14, "Symmetric SKyline"],
'nsk': [15, "Nonsymmetric SKyline"],
'jad': [16, "JAgged Diagonal"],
'uss': [17, "Unsymmetric Sparse Skyline"],
'vbr': [18, "Variable Block Row"],
'und': [19, "Undefined"]
}
# These univariate ufuncs preserve zeros.
_ufuncs_with_fixed_point_at_zero = frozenset([
np.sin, np.tan, np.arcsin, np.arctan, np.sinh, np.tanh, np.arcsinh,
np.arctanh, np.rint, np.sign, np.expm1, np.log1p, np.deg2rad,
np.rad2deg, np.floor, np.ceil, np.trunc, np.sqrt])
MAXPRINT = 50
class _spbase:
""" This class provides a base class for all sparse arrays. It
cannot be instantiated. Most of the work is provided by subclasses.
"""
__array_priority__ = 10.1
_format = 'und' # undefined
@property
def ndim(self) -> int:
return len(self._shape)
@property
def _shape_as_2d(self):
s = self._shape
return (1, s[-1]) if len(s) == 1 else s
@property
def _bsr_container(self):
from ._bsr import bsr_array
return bsr_array
@property
def _coo_container(self):
from ._coo import coo_array
return coo_array
@property
def _csc_container(self):
from ._csc import csc_array
return csc_array
@property
def _csr_container(self):
from ._csr import csr_array
return csr_array
@property
def _dia_container(self):
from ._dia import dia_array
return dia_array
@property
def _dok_container(self):
from ._dok import dok_array
return dok_array
@property
def _lil_container(self):
from ._lil import lil_array
return lil_array
def __init__(self, maxprint=MAXPRINT):
self._shape = None
if self.__class__.__name__ == '_spbase':
raise ValueError("This class is not intended"
" to be instantiated directly.")
self.maxprint = maxprint
# Use this in 1.14.0 and later:
#
# @property
# def shape(self):
# return self._shape
def reshape(self, *args, **kwargs):
"""reshape(self, shape, order='C', copy=False)
Gives a new shape to a sparse array/matrix without changing its data.
Parameters
----------
shape : length-2 tuple of ints
The new shape should be compatible with the original shape.
order : {'C', 'F'}, optional
Read the elements using this index order. 'C' means to read and
write the elements using C-like index order; e.g., read entire first
row, then second row, etc. 'F' means to read and write the elements
using Fortran-like index order; e.g., read entire first column, then
second column, etc.
copy : bool, optional
Indicates whether or not attributes of self should be copied
whenever possible. The degree to which attributes are copied varies
depending on the type of sparse array being used.
Returns
-------
reshaped : sparse array/matrix
A sparse array/matrix with the given `shape`, not necessarily of the same
format as the current object.
See Also
--------
numpy.reshape : NumPy's implementation of 'reshape' for ndarrays
"""
# If the shape already matches, don't bother doing an actual reshape
# Otherwise, the default is to convert to COO and use its reshape
is_array = isinstance(self, sparray)
shape = check_shape(args, self.shape, allow_1d=is_array)
order, copy = check_reshape_kwargs(kwargs)
if shape == self.shape:
if copy:
return self.copy()
else:
return self
return self.tocoo(copy=copy).reshape(shape, order=order, copy=False)
def resize(self, shape):
"""Resize the array/matrix in-place to dimensions given by ``shape``
Any elements that lie within the new shape will remain at the same
indices, while non-zero elements lying outside the new shape are
removed.
Parameters
----------
shape : (int, int)
number of rows and columns in the new array/matrix
Notes
-----
The semantics are not identical to `numpy.ndarray.resize` or
`numpy.resize`. Here, the same data will be maintained at each index
before and after reshape, if that index is within the new bounds. In
numpy, resizing maintains contiguity of the array, moving elements
around in the logical array but not within a flattened representation.
We give no guarantees about whether the underlying data attributes
(arrays, etc.) will be modified in place or replaced with new objects.
"""
# As an inplace operation, this requires implementation in each format.
raise NotImplementedError(
f'{type(self).__name__}.resize is not implemented')
def astype(self, dtype, casting='unsafe', copy=True):
"""Cast the array/matrix elements to a specified type.
Parameters
----------
dtype : string or numpy dtype
Typecode or data-type to which to cast the data.
casting : {'no', 'equiv', 'safe', 'same_kind', 'unsafe'}, optional
Controls what kind of data casting may occur.
Defaults to 'unsafe' for backwards compatibility.
'no' means the data types should not be cast at all.
'equiv' means only byte-order changes are allowed.
'safe' means only casts which can preserve values are allowed.
'same_kind' means only safe casts or casts within a kind,
like float64 to float32, are allowed.
'unsafe' means any data conversions may be done.
copy : bool, optional
If `copy` is `False`, the result might share some memory with this
array/matrix. If `copy` is `True`, it is guaranteed that the result and
this array/matrix do not share any memory.
"""
dtype = np.dtype(dtype)
if self.dtype != dtype:
return self.tocsr().astype(
dtype, casting=casting, copy=copy).asformat(self.format)
elif copy:
return self.copy()
else:
return self
@classmethod
def _ascontainer(cls, X, **kwargs):
if issubclass(cls, sparray):
return np.asarray(X, **kwargs)
else:
return asmatrix(X, **kwargs)
@classmethod
def _container(cls, X, **kwargs):
if issubclass(cls, sparray):
return np.array(X, **kwargs)
else:
return matrix(X, **kwargs)
def _asfptype(self):
"""Upcast array to a floating point format (if necessary)"""
fp_types = ['f', 'd', 'F', 'D']
if self.dtype.char in fp_types:
return self
else:
for fp_type in fp_types:
if self.dtype <= np.dtype(fp_type):
return self.astype(fp_type)
raise TypeError('cannot upcast [%s] to a floating '
'point format' % self.dtype.name)
def __iter__(self):
for r in range(self.shape[0]):
yield self[r]
def _getmaxprint(self):
"""Maximum number of elements to display when printed."""
return self.maxprint
def count_nonzero(self):
"""Number of non-zero entries, equivalent to
np.count_nonzero(a.toarray())
Unlike the nnz property, which return the number of stored
entries (the length of the data attribute), this method counts the
actual number of non-zero entries in data.
"""
raise NotImplementedError("count_nonzero not implemented for %s." %
self.__class__.__name__)
def _getnnz(self, axis=None):
"""Number of stored values, including explicit zeros.
Parameters
----------
axis : None, 0, or 1
Select between the number of values across the whole array, in
each column, or in each row.
See also
--------
count_nonzero : Number of non-zero entries
"""
raise NotImplementedError("getnnz not implemented for %s." %
self.__class__.__name__)
@property
def nnz(self) -> int:
"""Number of stored values, including explicit zeros.
See also
--------
count_nonzero : Number of non-zero entries
"""
return self._getnnz()
@property
def size(self) -> int:
"""Number of stored values.
See also
--------
count_nonzero : Number of non-zero values.
"""
return self._getnnz()
@property
def format(self) -> str:
"""Format string for matrix."""
return self._format
@property
def A(self) -> np.ndarray:
"""DEPRECATED: Return a dense array.
.. deprecated:: 1.11.0
`.A` is deprecated and will be removed in v1.14.0.
Use `.toarray()` instead.
"""
if isinstance(self, sparray):
message = ("`.A` is deprecated and will be removed in v1.14.0. "
"Use `.toarray()` instead.")
warn(VisibleDeprecationWarning(message), stacklevel=2)
return self.toarray()
@property
def T(self):
"""Transpose."""
return self.transpose()
@property
def H(self):
"""DEPRECATED: Returns the (complex) conjugate transpose.
.. deprecated:: 1.11.0
`.H` is deprecated and will be removed in v1.14.0.
Please use `.T.conjugate()` instead.
"""
if isinstance(self, sparray):
message = ("`.H` is deprecated and will be removed in v1.14.0. "
"Please use `.T.conjugate()` instead.")
warn(VisibleDeprecationWarning(message), stacklevel=2)
return self.T.conjugate()
@property
def real(self):
return self._real()
@property
def imag(self):
return self._imag()
def __repr__(self):
_, format_name = _formats[self.format]
sparse_cls = 'array' if isinstance(self, sparray) else 'matrix'
shape_str = 'x'.join(str(x) for x in self.shape)
return (
f"<{shape_str} sparse {sparse_cls} of type '{self.dtype.type}'\n"
f"\twith {self.nnz} stored elements in {format_name} format>"
)
def __str__(self):
maxprint = self._getmaxprint()
A = self.tocoo()
# helper function, outputs "(i,j) v"
def tostr(row, col, data):
triples = zip(list(zip(row, col)), data)
return '\n'.join([(' {}\t{}'.format(*t)) for t in triples])
if self.nnz > maxprint:
half = maxprint // 2
out = tostr(A.row[:half], A.col[:half], A.data[:half])
out += "\n :\t:\n"
half = maxprint - maxprint//2
out += tostr(A.row[-half:], A.col[-half:], A.data[-half:])
else:
out = tostr(A.row, A.col, A.data)
return out
def __bool__(self): # Simple -- other ideas?
if self.shape == (1, 1):
return self.nnz != 0
else:
raise ValueError("The truth value of an array with more than one "
"element is ambiguous. Use a.any() or a.all().")
__nonzero__ = __bool__
# What should len(sparse) return? For consistency with dense matrices,
# perhaps it should be the number of rows? But for some uses the number of
# non-zeros is more important. For now, raise an exception!
def __len__(self):
raise TypeError("sparse array length is ambiguous; use getnnz()"
" or shape[0]")
def asformat(self, format, copy=False):
"""Return this array/matrix in the passed format.
Parameters
----------
format : {str, None}
The desired sparse format ("csr", "csc", "lil", "dok", "array", ...)
or None for no conversion.
copy : bool, optional
If True, the result is guaranteed to not share data with self.
Returns
-------
A : This array/matrix in the passed format.
"""
if format is None or format == self.format:
if copy:
return self.copy()
else:
return self
else:
try:
convert_method = getattr(self, 'to' + format)
except AttributeError as e:
raise ValueError(f'Format {format} is unknown.') from e
# Forward the copy kwarg, if it's accepted.
try:
return convert_method(copy=copy)
except TypeError:
return convert_method()
###################################################################
# NOTE: All arithmetic operations use csr_matrix by default.
# Therefore a new sparse array format just needs to define a
# .tocsr() method to provide arithmetic support. Any of these
# methods can be overridden for efficiency.
####################################################################
def multiply(self, other):
"""Point-wise multiplication by another array/matrix."""
return self.tocsr().multiply(other)
def maximum(self, other):
"""Element-wise maximum between this and another array/matrix."""
return self.tocsr().maximum(other)
def minimum(self, other):
"""Element-wise minimum between this and another array/matrix."""
return self.tocsr().minimum(other)
def dot(self, other):
"""Ordinary dot product
Examples
--------
>>> import numpy as np
>>> from scipy.sparse import csr_array
>>> A = csr_array([[1, 2, 0], [0, 0, 3], [4, 0, 5]])
>>> v = np.array([1, 0, -1])
>>> A.dot(v)
array([ 1, -3, -1], dtype=int64)
"""
if np.isscalar(other):
return self * other
else:
return self @ other
def power(self, n, dtype=None):
"""Element-wise power."""
return self.tocsr().power(n, dtype=dtype)
def __eq__(self, other):
return self.tocsr().__eq__(other)
def __ne__(self, other):
return self.tocsr().__ne__(other)
def __lt__(self, other):
return self.tocsr().__lt__(other)
def __gt__(self, other):
return self.tocsr().__gt__(other)
def __le__(self, other):
return self.tocsr().__le__(other)
def __ge__(self, other):
return self.tocsr().__ge__(other)
def __abs__(self):
return abs(self.tocsr())
def __round__(self, ndigits=0):
return round(self.tocsr(), ndigits=ndigits)
def _add_sparse(self, other):
return self.tocsr()._add_sparse(other)
def _add_dense(self, other):
return self.tocoo()._add_dense(other)
def _sub_sparse(self, other):
return self.tocsr()._sub_sparse(other)
def _sub_dense(self, other):
return self.todense() - other
def _rsub_dense(self, other):
# note: this can't be replaced by other + (-self) for unsigned types
return other - self.todense()
def __add__(self, other): # self + other
if isscalarlike(other):
if other == 0:
return self.copy()
# Now we would add this scalar to every element.
raise NotImplementedError('adding a nonzero scalar to a '
'sparse array is not supported')
elif issparse(other):
if other.shape != self.shape:
raise ValueError("inconsistent shapes")
return self._add_sparse(other)
elif isdense(other):
other = np.broadcast_to(other, self.shape)
return self._add_dense(other)
else:
return NotImplemented
def __radd__(self,other): # other + self
return self.__add__(other)
def __sub__(self, other): # self - other
if isscalarlike(other):
if other == 0:
return self.copy()
raise NotImplementedError('subtracting a nonzero scalar from a '
'sparse array is not supported')
elif issparse(other):
if other.shape != self.shape:
raise ValueError("inconsistent shapes")
return self._sub_sparse(other)
elif isdense(other):
other = np.broadcast_to(other, self.shape)
return self._sub_dense(other)
else:
return NotImplemented
def __rsub__(self,other): # other - self
if isscalarlike(other):
if other == 0:
return -self.copy()
raise NotImplementedError('subtracting a sparse array from a '
'nonzero scalar is not supported')
elif isdense(other):
other = np.broadcast_to(other, self.shape)
return self._rsub_dense(other)
else:
return NotImplemented
def _matmul_dispatch(self, other):
"""np.array-like matmul & `np.matrix`-like mul, i.e. `dot` or `NotImplemented`
interpret other and call one of the following
self._mul_scalar()
self._matmul_vector()
self._matmul_multivector()
self._matmul_sparse()
"""
# This method has to be different from `__matmul__` because it is also
# called by sparse matrix classes.
# Currently matrix multiplication is only supported
# for 2D arrays. Hence we unpacked and use only the
# two last axes' lengths.
M, N = self._shape_as_2d
if other.__class__ is np.ndarray:
# Fast path for the most common case
if other.shape == (N,):
return self._matmul_vector(other)
elif other.shape == (N, 1):
result = self._matmul_vector(other.ravel())
if self.ndim == 1:
return result
return result.reshape(M, 1)
elif other.ndim == 2 and other.shape[0] == N:
return self._matmul_multivector(other)
if isscalarlike(other):
# scalar value
return self._mul_scalar(other)
if issparse(other):
if self.shape[-1] != other.shape[0]:
raise ValueError('dimension mismatch')
if other.ndim == 1:
raise ValueError('Cannot yet multiply a 1d sparse array')
return self._matmul_sparse(other)
# If it's a list or whatever, treat it like an array
other_a = np.asanyarray(other)
if other_a.ndim == 0 and other_a.dtype == np.object_:
# Not interpretable as an array; return NotImplemented so that
# other's __rmatmul__ can kick in if that's implemented.
return NotImplemented
try:
other.shape
except AttributeError:
other = other_a
if other.ndim == 1 or other.ndim == 2 and other.shape[1] == 1:
# dense row or column vector
if other.shape != (N,) and other.shape != (N, 1):
raise ValueError('dimension mismatch')
result = self._matmul_vector(np.ravel(other))
if isinstance(other, np.matrix):
result = self._ascontainer(result)
if other.ndim == 2 and other.shape[1] == 1:
# If 'other' was an (nx1) column vector, reshape the result
result = result.reshape(-1, 1)
return result
elif other.ndim == 2:
##
# dense 2D array or matrix ("multivector")
if other.shape[0] != N:
raise ValueError('dimension mismatch')
result = self._matmul_multivector(np.asarray(other))
if isinstance(other, np.matrix):
result = self._ascontainer(result)
return result
else:
raise ValueError('could not interpret dimensions')
def __mul__(self, *args, **kwargs):
return self.multiply(*args, **kwargs)
def __rmul__(self, *args, **kwargs): # other * self
return self.multiply(*args, **kwargs)
# by default, use CSR for __mul__ handlers
def _mul_scalar(self, other):
return self.tocsr()._mul_scalar(other)
def _matmul_vector(self, other):
return self.tocsr()._matmul_vector(other)
def _matmul_multivector(self, other):
return self.tocsr()._matmul_multivector(other)
def _matmul_sparse(self, other):
return self.tocsr()._matmul_sparse(other)
def _rmatmul_dispatch(self, other):
if isscalarlike(other):
return self._mul_scalar(other)
else:
# Don't use asarray unless we have to
try:
tr = other.transpose()
except AttributeError:
tr = np.asarray(other).transpose()
ret = self.transpose()._matmul_dispatch(tr)
if ret is NotImplemented:
return NotImplemented
return ret.transpose()
#######################
# matmul (@) operator #
#######################
def __matmul__(self, other):
if isscalarlike(other):
raise ValueError("Scalar operands are not allowed, "
"use '*' instead")
return self._matmul_dispatch(other)
def __rmatmul__(self, other):
if isscalarlike(other):
raise ValueError("Scalar operands are not allowed, "
"use '*' instead")
return self._rmatmul_dispatch(other)
####################
# Other Arithmetic #
####################
def _divide(self, other, true_divide=False, rdivide=False):
if isscalarlike(other):
if rdivide:
if true_divide:
return np.true_divide(other, self.todense())
else:
return np.divide(other, self.todense())
if true_divide and np.can_cast(self.dtype, np.float64):
return self.astype(np.float64)._mul_scalar(1./other)
else:
r = self._mul_scalar(1./other)
scalar_dtype = np.asarray(other).dtype
if (np.issubdtype(self.dtype, np.integer) and
np.issubdtype(scalar_dtype, np.integer)):
return r.astype(self.dtype)
else:
return r
elif isdense(other):
if not rdivide:
if true_divide:
recip = np.true_divide(1., other)
else:
recip = np.divide(1., other)
return self.multiply(recip)
else:
if true_divide:
return np.true_divide(other, self.todense())
else:
return np.divide(other, self.todense())
elif issparse(other):
if rdivide:
return other._divide(self, true_divide, rdivide=False)
self_csr = self.tocsr()
if true_divide and np.can_cast(self.dtype, np.float64):
return self_csr.astype(np.float64)._divide_sparse(other)
else:
return self_csr._divide_sparse(other)
else:
return NotImplemented
def __truediv__(self, other):
return self._divide(other, true_divide=True)
def __div__(self, other):
# Always do true division
return self._divide(other, true_divide=True)
def __rtruediv__(self, other):
# Implementing this as the inverse would be too magical -- bail out
return NotImplemented
def __rdiv__(self, other):
# Implementing this as the inverse would be too magical -- bail out
return NotImplemented
def __neg__(self):
return -self.tocsr()
def __iadd__(self, other):
return NotImplemented
def __isub__(self, other):
return NotImplemented
def __imul__(self, other):
return NotImplemented
def __idiv__(self, other):
return self.__itruediv__(other)
def __itruediv__(self, other):
return NotImplemented
def __pow__(self, *args, **kwargs):
return self.power(*args, **kwargs)
def transpose(self, axes=None, copy=False):
"""
Reverses the dimensions of the sparse array/matrix.
Parameters
----------
axes : None, optional
This argument is in the signature *solely* for NumPy
compatibility reasons. Do not pass in anything except
for the default value.
copy : bool, optional
Indicates whether or not attributes of `self` should be
copied whenever possible. The degree to which attributes
are copied varies depending on the type of sparse array/matrix
being used.
Returns
-------
p : `self` with the dimensions reversed.
Notes
-----
If `self` is a `csr_array` or a `csc_array`, then this will return a
`csc_array` or a `csr_array`, respectively.
See Also
--------
numpy.transpose : NumPy's implementation of 'transpose' for ndarrays
"""
return self.tocsr(copy=copy).transpose(axes=axes, copy=False)
def conjugate(self, copy=True):
"""Element-wise complex conjugation.
If the array/matrix is of non-complex data type and `copy` is False,
this method does nothing and the data is not copied.
Parameters
----------
copy : bool, optional
If True, the result is guaranteed to not share data with self.
Returns
-------
A : The element-wise complex conjugate.
"""
if np.issubdtype(self.dtype, np.complexfloating):
return self.tocsr(copy=copy).conjugate(copy=False)
elif copy:
return self.copy()
else:
return self
def conj(self, copy=True):
return self.conjugate(copy=copy)
conj.__doc__ = conjugate.__doc__
def _real(self):
return self.tocsr()._real()
def _imag(self):
return self.tocsr()._imag()
def nonzero(self):
"""Nonzero indices of the array/matrix.
Returns a tuple of arrays (row,col) containing the indices
of the non-zero elements of the array.
Examples
--------
>>> from scipy.sparse import csr_array
>>> A = csr_array([[1,2,0],[0,0,3],[4,0,5]])
>>> A.nonzero()
(array([0, 0, 1, 2, 2]), array([0, 1, 2, 0, 2]))
"""
# convert to COOrdinate format
A = self.tocoo()
nz_mask = A.data != 0
return (A.row[nz_mask], A.col[nz_mask])
def _getcol(self, j):
"""Returns a copy of column j of the array, as an (m x 1) sparse
array (column vector).
"""
if self.ndim == 1:
raise ValueError("getcol not provided for 1d arrays. Use indexing A[j]")
# Subclasses should override this method for efficiency.
# Post-multiply by a (n x 1) column vector 'a' containing all zeros
# except for a_j = 1
N = self.shape[-1]
if j < 0:
j += N
if j < 0 or j >= N:
raise IndexError("index out of bounds")
col_selector = self._csc_container(([1], [[j], [0]]),
shape=(N, 1), dtype=self.dtype)
result = self @ col_selector
return result
def _getrow(self, i):
"""Returns a copy of row i of the array, as a (1 x n) sparse
array (row vector).
"""
if self.ndim == 1:
raise ValueError("getrow not meaningful for a 1d array")
# Subclasses should override this method for efficiency.
# Pre-multiply by a (1 x m) row vector 'a' containing all zeros
# except for a_i = 1
M = self.shape[0]
if i < 0:
i += M
if i < 0 or i >= M:
raise IndexError("index out of bounds")
row_selector = self._csr_container(([1], [[0], [i]]),
shape=(1, M), dtype=self.dtype)
return row_selector @ self
# The following dunder methods cannot be implemented.
#
# def __array__(self):
# # Sparse matrices rely on NumPy wrapping them in object arrays under
# # the hood to make unary ufuncs work on them. So we cannot raise
# # TypeError here - which would be handy to not give users object
# # arrays they probably don't want (they're looking for `.toarray()`).
# #
# # Conversion with `toarray()` would also break things because of the
# # behavior discussed above, plus we want to avoid densification by
# # accident because that can too easily blow up memory.
#
# def __array_ufunc__(self):
# # We cannot implement __array_ufunc__ due to mismatching semantics.
# # See gh-7707 and gh-7349 for details.
#
# def __array_function__(self):
# # We cannot implement __array_function__ due to mismatching semantics.
# # See gh-10362 for details.
def todense(self, order=None, out=None):
"""
Return a dense representation of this sparse array/matrix.
Parameters
----------
order : {'C', 'F'}, optional
Whether to store multi-dimensional data in C (row-major)
or Fortran (column-major) order in memory. The default
is 'None', which provides no ordering guarantees.
Cannot be specified in conjunction with the `out`
argument.
out : ndarray, 2-D, optional
If specified, uses this array (or `numpy.matrix`) as the
output buffer instead of allocating a new array to
return. The provided array must have the same shape and
dtype as the sparse array/matrix on which you are calling the
method.
Returns
-------
arr : numpy.matrix, 2-D
A NumPy matrix object with the same shape and containing
the same data represented by the sparse array/matrix, with the
requested memory order. If `out` was passed and was an
array (rather than a `numpy.matrix`), it will be filled
with the appropriate values and returned wrapped in a
`numpy.matrix` object that shares the same memory.
"""
return self._ascontainer(self.toarray(order=order, out=out))
def toarray(self, order=None, out=None):
"""
Return a dense ndarray representation of this sparse array/matrix.
Parameters
----------
order : {'C', 'F'}, optional
Whether to store multidimensional data in C (row-major)
or Fortran (column-major) order in memory. The default
is 'None', which provides no ordering guarantees.
Cannot be specified in conjunction with the `out`
argument.
out : ndarray, 2-D, optional
If specified, uses this array as the output buffer
instead of allocating a new array to return. The provided
array must have the same shape and dtype as the sparse
array/matrix on which you are calling the method. For most
sparse types, `out` is required to be memory contiguous
(either C or Fortran ordered).
Returns
-------
arr : ndarray, 2-D
An array with the same shape and containing the same
data represented by the sparse array/matrix, with the requested
memory order. If `out` was passed, the same object is
returned after being modified in-place to contain the
appropriate values.
"""
return self.tocoo(copy=False).toarray(order=order, out=out)
# Any sparse array format deriving from _spbase must define one of
# tocsr or tocoo. The other conversion methods may be implemented for
# efficiency, but are not required.
def tocsr(self, copy=False):
"""Convert this array/matrix to Compressed Sparse Row format.
With copy=False, the data/indices may be shared between this array/matrix and
the resultant csr_array/matrix.
"""
return self.tocoo(copy=copy).tocsr(copy=False)
def todok(self, copy=False):
"""Convert this array/matrix to Dictionary Of Keys format.
With copy=False, the data/indices may be shared between this array/matrix and
the resultant dok_array/matrix.
"""
return self.tocoo(copy=copy).todok(copy=False)
def tocoo(self, copy=False):
"""Convert this array/matrix to COOrdinate format.
With copy=False, the data/indices may be shared between this array/matrix and
the resultant coo_array/matrix.
"""
return self.tocsr(copy=False).tocoo(copy=copy)
def tolil(self, copy=False):
"""Convert this array/matrix to List of Lists format.
With copy=False, the data/indices may be shared between this array/matrix and
the resultant lil_array/matrix.
"""
return self.tocsr(copy=False).tolil(copy=copy)
def todia(self, copy=False):
"""Convert this array/matrix to sparse DIAgonal format.
With copy=False, the data/indices may be shared between this array/matrix and
the resultant dia_array/matrix.
"""
return self.tocoo(copy=copy).todia(copy=False)
def tobsr(self, blocksize=None, copy=False):
"""Convert this array/matrix to Block Sparse Row format.
With copy=False, the data/indices may be shared between this array/matrix and
the resultant bsr_array/matrix.
When blocksize=(R, C) is provided, it will be used for construction of
the bsr_array/matrix.
"""
return self.tocsr(copy=False).tobsr(blocksize=blocksize, copy=copy)
def tocsc(self, copy=False):
"""Convert this array/matrix to Compressed Sparse Column format.
With copy=False, the data/indices may be shared between this array/matrix and
the resultant csc_array/matrix.
"""
return self.tocsr(copy=copy).tocsc(copy=False)
def copy(self):
"""Returns a copy of this array/matrix.
No data/indices will be shared between the returned value and current
array/matrix.
"""
return self.__class__(self, copy=True)
def sum(self, axis=None, dtype=None, out=None):
"""
Sum the array/matrix elements over a given axis.
Parameters
----------
axis : {-2, -1, 0, 1, None} optional
Axis along which the sum is computed. The default is to
compute the sum of all the array/matrix elements, returning a scalar
(i.e., `axis` = `None`).
dtype : dtype, optional
The type of the returned array/matrix and of the accumulator in which
the elements are summed. The dtype of `a` is used by default
unless `a` has an integer dtype of less precision than the default
platform integer. In that case, if `a` is signed then the platform
integer is used while if `a` is unsigned then an unsigned integer
of the same precision as the platform integer is used.
.. versionadded:: 0.18.0
out : np.matrix, optional
Alternative output matrix in which to place the result. It must
have the same shape as the expected output, but the type of the
output values will be cast if necessary.
.. versionadded:: 0.18.0
Returns
-------
sum_along_axis : np.matrix
A matrix with the same shape as `self`, with the specified
axis removed.
See Also
--------
numpy.matrix.sum : NumPy's implementation of 'sum' for matrices
"""
validateaxis(axis)
# Mimic numpy's casting.
res_dtype = get_sum_dtype(self.dtype)
if self.ndim == 1:
if axis not in (None, -1, 0):
raise ValueError("axis must be None, -1 or 0")
ret = (self @ np.ones(self.shape, dtype=res_dtype)).astype(dtype)
if out is not None:
if any(dim != 1 for dim in out.shape):
raise ValueError("dimensions do not match")
out[...] = ret
return ret
# We use multiplication by a matrix of ones to achieve this.
# For some sparse array formats more efficient methods are
# possible -- these should override this function.
M, N = self.shape
if axis is None:
# sum over rows and columns
return (
self @ self._ascontainer(np.ones((N, 1), dtype=res_dtype))
).sum(dtype=dtype, out=out)
if axis < 0:
axis += 2
# axis = 0 or 1 now
if axis == 0:
# sum over columns
ret = self._ascontainer(
np.ones((1, M), dtype=res_dtype)
) @ self
else:
# sum over rows
ret = self @ self._ascontainer(
np.ones((N, 1), dtype=res_dtype)
)
if out is not None and out.shape != ret.shape:
raise ValueError("dimensions do not match")
return ret.sum(axis=axis, dtype=dtype, out=out)
def mean(self, axis=None, dtype=None, out=None):
"""
Compute the arithmetic mean along the specified axis.
Returns the average of the array/matrix elements. The average is taken
over all elements in the array/matrix by default, otherwise over the
specified axis. `float64` intermediate and return values are used
for integer inputs.
Parameters
----------
axis : {-2, -1, 0, 1, None} optional
Axis along which the mean is computed. The default is to compute
the mean of all elements in the array/matrix (i.e., `axis` = `None`).
dtype : data-type, optional
Type to use in computing the mean. For integer inputs, the default
is `float64`; for floating point inputs, it is the same as the
input dtype.
.. versionadded:: 0.18.0
out : np.matrix, optional
Alternative output matrix in which to place the result. It must
have the same shape as the expected output, but the type of the
output values will be cast if necessary.
.. versionadded:: 0.18.0
Returns
-------
m : np.matrix
See Also
--------
numpy.matrix.mean : NumPy's implementation of 'mean' for matrices
"""
validateaxis(axis)
res_dtype = self.dtype.type
integral = (np.issubdtype(self.dtype, np.integer) or
np.issubdtype(self.dtype, np.bool_))
# output dtype
if dtype is None:
if integral:
res_dtype = np.float64
else:
res_dtype = np.dtype(dtype).type
# intermediate dtype for summation
inter_dtype = np.float64 if integral else res_dtype
inter_self = self.astype(inter_dtype)
if self.ndim == 1:
if axis not in (None, -1, 0):
raise ValueError("axis must be None, -1 or 0")
res = inter_self / self.shape[-1]
return res.sum(dtype=res_dtype, out=out)
if axis is None:
return (inter_self / (self.shape[0] * self.shape[1]))\
.sum(dtype=res_dtype, out=out)
if axis < 0:
axis += 2
# axis = 0 or 1 now
if axis == 0:
return (inter_self * (1.0 / self.shape[0])).sum(
axis=0, dtype=res_dtype, out=out)
else:
return (inter_self * (1.0 / self.shape[1])).sum(
axis=1, dtype=res_dtype, out=out)
def diagonal(self, k=0):
"""Returns the kth diagonal of the array/matrix.
Parameters
----------
k : int, optional
Which diagonal to get, corresponding to elements a[i, i+k].
Default: 0 (the main diagonal).
.. versionadded:: 1.0
See also
--------
numpy.diagonal : Equivalent numpy function.
Examples
--------
>>> from scipy.sparse import csr_array
>>> A = csr_array([[1, 2, 0], [0, 0, 3], [4, 0, 5]])
>>> A.diagonal()
array([1, 0, 5])
>>> A.diagonal(k=1)
array([2, 3])
"""
return self.tocsr().diagonal(k=k)
def trace(self, offset=0):
"""Returns the sum along diagonals of the sparse array/matrix.
Parameters
----------
offset : int, optional
Which diagonal to get, corresponding to elements a[i, i+offset].
Default: 0 (the main diagonal).
"""
return self.diagonal(k=offset).sum()
def setdiag(self, values, k=0):
"""
Set diagonal or off-diagonal elements of the array/matrix.
Parameters
----------
values : array_like
New values of the diagonal elements.
Values may have any length. If the diagonal is longer than values,
then the remaining diagonal entries will not be set. If values are
longer than the diagonal, then the remaining values are ignored.
If a scalar value is given, all of the diagonal is set to it.
k : int, optional
Which off-diagonal to set, corresponding to elements a[i,i+k].
Default: 0 (the main diagonal).
"""
M, N = self.shape
if (k > 0 and k >= N) or (k < 0 and -k >= M):
raise ValueError("k exceeds array dimensions")
self._setdiag(np.asarray(values), k)
def _setdiag(self, values, k):
"""This part of the implementation gets overridden by the
different formats.
"""
M, N = self.shape
if k < 0:
if values.ndim == 0:
# broadcast
max_index = min(M+k, N)
for i in range(max_index):
self[i - k, i] = values
else:
max_index = min(M+k, N, len(values))
if max_index <= 0:
return
for i, v in enumerate(values[:max_index]):
self[i - k, i] = v
else:
if values.ndim == 0:
# broadcast
max_index = min(M, N-k)
for i in range(max_index):
self[i, i + k] = values
else:
max_index = min(M, N-k, len(values))
if max_index <= 0:
return
for i, v in enumerate(values[:max_index]):
self[i, i + k] = v
def _process_toarray_args(self, order, out):
if out is not None:
if order is not None:
raise ValueError('order cannot be specified if out '
'is not None')
if out.shape != self.shape or out.dtype != self.dtype:
raise ValueError('out array must be same dtype and shape as '
'sparse array')
out[...] = 0.
return out
else:
return np.zeros(self.shape, dtype=self.dtype, order=order)
def _get_index_dtype(self, arrays=(), maxval=None, check_contents=False):
"""
Determine index dtype for array.
This wraps _sputils.get_index_dtype, providing compatibility for both
array and matrix API sparse matrices. Matrix API sparse matrices would
attempt to downcast the indices - which can be computationally
expensive and undesirable for users. The array API changes this
behaviour.
See discussion: https://github.com/scipy/scipy/issues/16774
The get_index_dtype import is due to implementation details of the test
suite. It allows the decorator ``with_64bit_maxval_limit`` to mock a
lower int32 max value for checks on the matrix API's downcasting
behaviour.
"""
from ._sputils import get_index_dtype
# Don't check contents for array API
return get_index_dtype(arrays,
maxval,
(check_contents and not isinstance(self, sparray)))
## All methods below are deprecated and should be removed in
## scipy 1.14.0
##
## Also uncomment the definition of shape above.
def get_shape(self):
"""Get shape of a sparse array/matrix.
.. deprecated:: 1.11.0
This method will be removed in SciPy 1.14.0.
Use `X.shape` instead.
"""
msg = (
"`get_shape` is deprecated and will be removed in v1.14.0; "
"use `X.shape` instead."
)
warn(msg, DeprecationWarning, stacklevel=2)
return self._shape
def set_shape(self, shape):
"""See `reshape`.
.. deprecated:: 1.11.0
This method will be removed in SciPy 1.14.0.
Use `X.reshape` instead.
"""
msg = (
"Shape assignment is deprecated and will be removed in v1.14.0; "
"use `reshape` instead."
)
warn(msg, DeprecationWarning, stacklevel=2)
# Make sure copy is False since this is in place
# Make sure format is unchanged because we are doing a __dict__ swap
new_self = self.reshape(shape, copy=False).asformat(self.format)
self.__dict__ = new_self.__dict__
shape = property(
fget=lambda self: self._shape,
fset=set_shape,
doc="""The shape of the array.
Note that, starting in SciPy 1.14.0, this property will no longer be
settable. To change the array shape, use `X.reshape` instead.
"""
)
def asfptype(self):
"""Upcast array/matrix to a floating point format (if necessary)
.. deprecated:: 1.11.0
This method is for internal use only, and will be removed from the
public API in SciPy 1.14.0.
"""
msg = (
"`asfptype` is an internal function, and is deprecated "
"as part of the public API. It will be removed in v1.14.0."
)
warn(msg, DeprecationWarning, stacklevel=2)
return self._asfptype()
def getmaxprint(self):
"""Maximum number of elements to display when printed.
.. deprecated:: 1.11.0
This method is for internal use only, and will be removed from the
public API in SciPy 1.14.0.
"""
msg = (
"`getmaxprint` is an internal function, and is deprecated "
"as part of the public API. It will be removed in v1.14.0."
)
warn(msg, DeprecationWarning, stacklevel=2)
return self._getmaxprint()
def getformat(self):
"""Sparse array/matrix storage format.
.. deprecated:: 1.11.0
This method will be removed in SciPy 1.14.0.
Use `X.format` instead.
"""
msg = (
"`getformat` is deprecated and will be removed in v1.14.0; "
"use `X.format` instead."
)
warn(msg, DeprecationWarning, stacklevel=2)
return self.format
def getnnz(self, axis=None):
"""Number of stored values, including explicit zeros.
Parameters
----------
axis : None, 0, or 1
Select between the number of values across the whole array/matrix, in
each column, or in each row.
See also
--------
count_nonzero : Number of non-zero entries
"""
return self._getnnz(axis=axis)
def getH(self):
"""Return the Hermitian transpose of this array/matrix.
.. deprecated:: 1.11.0
This method will be removed in SciPy 1.14.0.
Use `X.conj().T` instead.
"""
msg = (
"`getH` is deprecated and will be removed in v1.14.0; "
"use `X.conj().T` instead."
)
warn(msg, DeprecationWarning, stacklevel=2)
return self.conjugate().transpose()
def getcol(self, j):
"""Returns a copy of column j of the array/matrix, as an (m x 1) sparse
array/matrix (column vector).
.. deprecated:: 1.11.0
This method will be removed in SciPy 1.14.0.
Use array/matrix indexing instead.
"""
msg = (
"`getcol` is deprecated and will be removed in v1.14.0; "
f"use `X[:, [{j}]]` instead."
)
warn(msg, DeprecationWarning, stacklevel=2)
return self._getcol(j)
def getrow(self, i):
"""Returns a copy of row i of the array/matrix, as a (1 x n) sparse
array/matrix (row vector).
.. deprecated:: 1.11.0
This method will be removed in SciPy 1.14.0.
Use array/matrix indexing instead.
"""
msg = (
"`getrow` is deprecated and will be removed in v1.14.0; "
f"use `X[[{i}]]` instead."
)
warn(msg, DeprecationWarning, stacklevel=2)
return self._getrow(i)
## End 1.14.0 deprecated methods
class sparray:
"""A namespace class to separate sparray from spmatrix"""
pass
sparray.__doc__ = _spbase.__doc__
def issparse(x):
"""Is `x` of a sparse array or sparse matrix type?
Parameters
----------
x
object to check for being a sparse array or sparse matrix
Returns
-------
bool
True if `x` is a sparse array or a sparse matrix, False otherwise
Examples
--------
>>> import numpy as np
>>> from scipy.sparse import csr_array, csr_matrix, issparse
>>> issparse(csr_matrix([[5]]))
True
>>> issparse(csr_array([[5]]))
True
>>> issparse(np.array([[5]]))
False
>>> issparse(5)
False
"""
return isinstance(x, _spbase)
def isspmatrix(x):
"""Is `x` of a sparse matrix type?
Parameters
----------
x
object to check for being a sparse matrix
Returns
-------
bool
True if `x` is a sparse matrix, False otherwise
Examples
--------
>>> import numpy as np
>>> from scipy.sparse import csr_array, csr_matrix, isspmatrix
>>> isspmatrix(csr_matrix([[5]]))
True
>>> isspmatrix(csr_array([[5]]))
False
>>> isspmatrix(np.array([[5]]))
False
>>> isspmatrix(5)
False
"""
return isinstance(x, spmatrix)