Fixed database typo and removed unnecessary class identifier.

This commit is contained in:
Batuhan Berk Başoğlu 2020-10-14 10:10:37 -04:00
parent 00ad49a143
commit 45fb349a7d
5098 changed files with 952558 additions and 85 deletions

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Copyright (c) 2003, The Regents of the University of California, through
Lawrence Berkeley National Laboratory (subject to receipt of any required
approvals from U.S. Dept. of Energy)
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
(1) Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
(2) Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
(3) Neither the name of Lawrence Berkeley National Laboratory, U.S. Dept. of
Energy nor the names of its contributors may be used to endorse or promote
products derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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"""
Linear Solvers
==============
The default solver is SuperLU (included in the scipy distribution),
which can solve real or complex linear systems in both single and
double precisions. It is automatically replaced by UMFPACK, if
available. Note that UMFPACK works in double precision only, so
switch it off by::
>>> use_solver(useUmfpack=False)
to solve in the single precision. See also use_solver documentation.
Example session::
>>> from scipy.sparse import csc_matrix, spdiags
>>> from numpy import array
>>> from scipy.sparse.linalg import spsolve, use_solver
>>>
>>> print("Inverting a sparse linear system:")
>>> print("The sparse matrix (constructed from diagonals):")
>>> a = spdiags([[1, 2, 3, 4, 5], [6, 5, 8, 9, 10]], [0, 1], 5, 5)
>>> b = array([1, 2, 3, 4, 5])
>>> print("Solve: single precision complex:")
>>> use_solver( useUmfpack = False )
>>> a = a.astype('F')
>>> x = spsolve(a, b)
>>> print(x)
>>> print("Error: ", a*x-b)
>>>
>>> print("Solve: double precision complex:")
>>> use_solver( useUmfpack = True )
>>> a = a.astype('D')
>>> x = spsolve(a, b)
>>> print(x)
>>> print("Error: ", a*x-b)
>>>
>>> print("Solve: double precision:")
>>> a = a.astype('d')
>>> x = spsolve(a, b)
>>> print(x)
>>> print("Error: ", a*x-b)
>>>
>>> print("Solve: single precision:")
>>> use_solver( useUmfpack = False )
>>> a = a.astype('f')
>>> x = spsolve(a, b.astype('f'))
>>> print(x)
>>> print("Error: ", a*x-b)
"""
#import umfpack
#__doc__ = '\n\n'.join( (__doc__, umfpack.__doc__) )
#del umfpack
from .linsolve import *
from ._superlu import SuperLU
from . import _add_newdocs
__all__ = [s for s in dir() if not s.startswith('_')]
from scipy._lib._testutils import PytestTester
test = PytestTester(__name__)
del PytestTester

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from numpy.lib import add_newdoc
add_newdoc('scipy.sparse.linalg.dsolve._superlu', 'SuperLU',
"""
LU factorization of a sparse matrix.
Factorization is represented as::
Pr * A * Pc = L * U
To construct these `SuperLU` objects, call the `splu` and `spilu`
functions.
Attributes
----------
shape
nnz
perm_c
perm_r
L
U
Methods
-------
solve
Notes
-----
.. versionadded:: 0.14.0
Examples
--------
The LU decomposition can be used to solve matrix equations. Consider:
>>> import numpy as np
>>> from scipy.sparse import csc_matrix, linalg as sla
>>> A = csc_matrix([[1,2,0,4],[1,0,0,1],[1,0,2,1],[2,2,1,0.]])
This can be solved for a given right-hand side:
>>> lu = sla.splu(A)
>>> b = np.array([1, 2, 3, 4])
>>> x = lu.solve(b)
>>> A.dot(x)
array([ 1., 2., 3., 4.])
The ``lu`` object also contains an explicit representation of the
decomposition. The permutations are represented as mappings of
indices:
>>> lu.perm_r
array([0, 2, 1, 3], dtype=int32)
>>> lu.perm_c
array([2, 0, 1, 3], dtype=int32)
The L and U factors are sparse matrices in CSC format:
>>> lu.L.A
array([[ 1. , 0. , 0. , 0. ],
[ 0. , 1. , 0. , 0. ],
[ 0. , 0. , 1. , 0. ],
[ 1. , 0.5, 0.5, 1. ]])
>>> lu.U.A
array([[ 2., 0., 1., 4.],
[ 0., 2., 1., 1.],
[ 0., 0., 1., 1.],
[ 0., 0., 0., -5.]])
The permutation matrices can be constructed:
>>> Pr = csc_matrix((np.ones(4), (lu.perm_r, np.arange(4))))
>>> Pc = csc_matrix((np.ones(4), (np.arange(4), lu.perm_c)))
We can reassemble the original matrix:
>>> (Pr.T * (lu.L * lu.U) * Pc.T).A
array([[ 1., 2., 0., 4.],
[ 1., 0., 0., 1.],
[ 1., 0., 2., 1.],
[ 2., 2., 1., 0.]])
""")
add_newdoc('scipy.sparse.linalg.dsolve._superlu', 'SuperLU', ('solve',
"""
solve(rhs[, trans])
Solves linear system of equations with one or several right-hand sides.
Parameters
----------
rhs : ndarray, shape (n,) or (n, k)
Right hand side(s) of equation
trans : {'N', 'T', 'H'}, optional
Type of system to solve::
'N': A * x == rhs (default)
'T': A^T * x == rhs
'H': A^H * x == rhs
i.e., normal, transposed, and hermitian conjugate.
Returns
-------
x : ndarray, shape ``rhs.shape``
Solution vector(s)
"""))
add_newdoc('scipy.sparse.linalg.dsolve._superlu', 'SuperLU', ('L',
"""
Lower triangular factor with unit diagonal as a
`scipy.sparse.csc_matrix`.
.. versionadded:: 0.14.0
"""))
add_newdoc('scipy.sparse.linalg.dsolve._superlu', 'SuperLU', ('U',
"""
Upper triangular factor as a `scipy.sparse.csc_matrix`.
.. versionadded:: 0.14.0
"""))
add_newdoc('scipy.sparse.linalg.dsolve._superlu', 'SuperLU', ('shape',
"""
Shape of the original matrix as a tuple of ints.
"""))
add_newdoc('scipy.sparse.linalg.dsolve._superlu', 'SuperLU', ('nnz',
"""
Number of nonzero elements in the matrix.
"""))
add_newdoc('scipy.sparse.linalg.dsolve._superlu', 'SuperLU', ('perm_c',
"""
Permutation Pc represented as an array of indices.
The column permutation matrix can be reconstructed via:
>>> Pc = np.zeros((n, n))
>>> Pc[np.arange(n), perm_c] = 1
"""))
add_newdoc('scipy.sparse.linalg.dsolve._superlu', 'SuperLU', ('perm_r',
"""
Permutation Pr represented as an array of indices.
The row permutation matrix can be reconstructed via:
>>> Pr = np.zeros((n, n))
>>> Pr[perm_r, np.arange(n)] = 1
"""))

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from warnings import warn
import numpy as np
from numpy import asarray
from scipy.sparse import (isspmatrix_csc, isspmatrix_csr, isspmatrix,
SparseEfficiencyWarning, csc_matrix, csr_matrix)
from scipy.sparse.sputils import is_pydata_spmatrix
from scipy.linalg import LinAlgError
import copy
from . import _superlu
noScikit = False
try:
import scikits.umfpack as umfpack
except ImportError:
noScikit = True
useUmfpack = not noScikit
__all__ = ['use_solver', 'spsolve', 'splu', 'spilu', 'factorized',
'MatrixRankWarning', 'spsolve_triangular']
class MatrixRankWarning(UserWarning):
pass
def use_solver(**kwargs):
"""
Select default sparse direct solver to be used.
Parameters
----------
useUmfpack : bool, optional
Use UMFPACK over SuperLU. Has effect only if scikits.umfpack is
installed. Default: True
assumeSortedIndices : bool, optional
Allow UMFPACK to skip the step of sorting indices for a CSR/CSC matrix.
Has effect only if useUmfpack is True and scikits.umfpack is installed.
Default: False
Notes
-----
The default sparse solver is umfpack when available
(scikits.umfpack is installed). This can be changed by passing
useUmfpack = False, which then causes the always present SuperLU
based solver to be used.
Umfpack requires a CSR/CSC matrix to have sorted column/row indices. If
sure that the matrix fulfills this, pass ``assumeSortedIndices=True``
to gain some speed.
"""
if 'useUmfpack' in kwargs:
globals()['useUmfpack'] = kwargs['useUmfpack']
if useUmfpack and 'assumeSortedIndices' in kwargs:
umfpack.configure(assumeSortedIndices=kwargs['assumeSortedIndices'])
def _get_umf_family(A):
"""Get umfpack family string given the sparse matrix dtype."""
_families = {
(np.float64, np.int32): 'di',
(np.complex128, np.int32): 'zi',
(np.float64, np.int64): 'dl',
(np.complex128, np.int64): 'zl'
}
f_type = np.sctypeDict[A.dtype.name]
i_type = np.sctypeDict[A.indices.dtype.name]
try:
family = _families[(f_type, i_type)]
except KeyError:
msg = 'only float64 or complex128 matrices with int32 or int64' \
' indices are supported! (got: matrix: %s, indices: %s)' \
% (f_type, i_type)
raise ValueError(msg)
# See gh-8278. Considered converting only if
# A.shape[0]*A.shape[1] > np.iinfo(np.int32).max,
# but that didn't always fix the issue.
family = family[0] + "l"
A_new = copy.copy(A)
A_new.indptr = np.array(A.indptr, copy=False, dtype=np.int64)
A_new.indices = np.array(A.indices, copy=False, dtype=np.int64)
return family, A_new
def spsolve(A, b, permc_spec=None, use_umfpack=True):
"""Solve the sparse linear system Ax=b, where b may be a vector or a matrix.
Parameters
----------
A : ndarray or sparse matrix
The square matrix A will be converted into CSC or CSR form
b : ndarray or sparse matrix
The matrix or vector representing the right hand side of the equation.
If a vector, b.shape must be (n,) or (n, 1).
permc_spec : str, optional
How to permute the columns of the matrix for sparsity preservation.
(default: 'COLAMD')
- ``NATURAL``: natural ordering.
- ``MMD_ATA``: minimum degree ordering on the structure of A^T A.
- ``MMD_AT_PLUS_A``: minimum degree ordering on the structure of A^T+A.
- ``COLAMD``: approximate minimum degree column ordering
use_umfpack : bool, optional
if True (default) then use umfpack for the solution. This is
only referenced if b is a vector and ``scikit-umfpack`` is installed.
Returns
-------
x : ndarray or sparse matrix
the solution of the sparse linear equation.
If b is a vector, then x is a vector of size A.shape[1]
If b is a matrix, then x is a matrix of size (A.shape[1], b.shape[1])
Notes
-----
For solving the matrix expression AX = B, this solver assumes the resulting
matrix X is sparse, as is often the case for very sparse inputs. If the
resulting X is dense, the construction of this sparse result will be
relatively expensive. In that case, consider converting A to a dense
matrix and using scipy.linalg.solve or its variants.
Examples
--------
>>> from scipy.sparse import csc_matrix
>>> from scipy.sparse.linalg import spsolve
>>> A = csc_matrix([[3, 2, 0], [1, -1, 0], [0, 5, 1]], dtype=float)
>>> B = csc_matrix([[2, 0], [-1, 0], [2, 0]], dtype=float)
>>> x = spsolve(A, B)
>>> np.allclose(A.dot(x).todense(), B.todense())
True
"""
if is_pydata_spmatrix(A):
A = A.to_scipy_sparse().tocsc()
if not (isspmatrix_csc(A) or isspmatrix_csr(A)):
A = csc_matrix(A)
warn('spsolve requires A be CSC or CSR matrix format',
SparseEfficiencyWarning)
# b is a vector only if b have shape (n,) or (n, 1)
b_is_sparse = isspmatrix(b) or is_pydata_spmatrix(b)
if not b_is_sparse:
b = asarray(b)
b_is_vector = ((b.ndim == 1) or (b.ndim == 2 and b.shape[1] == 1))
# sum duplicates for non-canonical format
A.sum_duplicates()
A = A.asfptype() # upcast to a floating point format
result_dtype = np.promote_types(A.dtype, b.dtype)
if A.dtype != result_dtype:
A = A.astype(result_dtype)
if b.dtype != result_dtype:
b = b.astype(result_dtype)
# validate input shapes
M, N = A.shape
if (M != N):
raise ValueError("matrix must be square (has shape %s)" % ((M, N),))
if M != b.shape[0]:
raise ValueError("matrix - rhs dimension mismatch (%s - %s)"
% (A.shape, b.shape[0]))
use_umfpack = use_umfpack and useUmfpack
if b_is_vector and use_umfpack:
if b_is_sparse:
b_vec = b.toarray()
else:
b_vec = b
b_vec = asarray(b_vec, dtype=A.dtype).ravel()
if noScikit:
raise RuntimeError('Scikits.umfpack not installed.')
if A.dtype.char not in 'dD':
raise ValueError("convert matrix data to double, please, using"
" .astype(), or set linsolve.useUmfpack = False")
umf_family, A = _get_umf_family(A)
umf = umfpack.UmfpackContext(umf_family)
x = umf.linsolve(umfpack.UMFPACK_A, A, b_vec,
autoTranspose=True)
else:
if b_is_vector and b_is_sparse:
b = b.toarray()
b_is_sparse = False
if not b_is_sparse:
if isspmatrix_csc(A):
flag = 1 # CSC format
else:
flag = 0 # CSR format
options = dict(ColPerm=permc_spec)
x, info = _superlu.gssv(N, A.nnz, A.data, A.indices, A.indptr,
b, flag, options=options)
if info != 0:
warn("Matrix is exactly singular", MatrixRankWarning)
x.fill(np.nan)
if b_is_vector:
x = x.ravel()
else:
# b is sparse
Afactsolve = factorized(A)
if not (isspmatrix_csc(b) or is_pydata_spmatrix(b)):
warn('spsolve is more efficient when sparse b '
'is in the CSC matrix format', SparseEfficiencyWarning)
b = csc_matrix(b)
# Create a sparse output matrix by repeatedly applying
# the sparse factorization to solve columns of b.
data_segs = []
row_segs = []
col_segs = []
for j in range(b.shape[1]):
bj = np.asarray(b[:, j].todense()).ravel()
xj = Afactsolve(bj)
w = np.flatnonzero(xj)
segment_length = w.shape[0]
row_segs.append(w)
col_segs.append(np.full(segment_length, j, dtype=int))
data_segs.append(np.asarray(xj[w], dtype=A.dtype))
sparse_data = np.concatenate(data_segs)
sparse_row = np.concatenate(row_segs)
sparse_col = np.concatenate(col_segs)
x = A.__class__((sparse_data, (sparse_row, sparse_col)),
shape=b.shape, dtype=A.dtype)
if is_pydata_spmatrix(b):
x = b.__class__(x)
return x
def splu(A, permc_spec=None, diag_pivot_thresh=None,
relax=None, panel_size=None, options=dict()):
"""
Compute the LU decomposition of a sparse, square matrix.
Parameters
----------
A : sparse matrix
Sparse matrix to factorize. Should be in CSR or CSC format.
permc_spec : str, optional
How to permute the columns of the matrix for sparsity preservation.
(default: 'COLAMD')
- ``NATURAL``: natural ordering.
- ``MMD_ATA``: minimum degree ordering on the structure of A^T A.
- ``MMD_AT_PLUS_A``: minimum degree ordering on the structure of A^T+A.
- ``COLAMD``: approximate minimum degree column ordering
diag_pivot_thresh : float, optional
Threshold used for a diagonal entry to be an acceptable pivot.
See SuperLU user's guide for details [1]_
relax : int, optional
Expert option for customizing the degree of relaxing supernodes.
See SuperLU user's guide for details [1]_
panel_size : int, optional
Expert option for customizing the panel size.
See SuperLU user's guide for details [1]_
options : dict, optional
Dictionary containing additional expert options to SuperLU.
See SuperLU user guide [1]_ (section 2.4 on the 'Options' argument)
for more details. For example, you can specify
``options=dict(Equil=False, IterRefine='SINGLE'))``
to turn equilibration off and perform a single iterative refinement.
Returns
-------
invA : scipy.sparse.linalg.SuperLU
Object, which has a ``solve`` method.
See also
--------
spilu : incomplete LU decomposition
Notes
-----
This function uses the SuperLU library.
References
----------
.. [1] SuperLU http://crd.lbl.gov/~xiaoye/SuperLU/
Examples
--------
>>> from scipy.sparse import csc_matrix
>>> from scipy.sparse.linalg import splu
>>> A = csc_matrix([[1., 0., 0.], [5., 0., 2.], [0., -1., 0.]], dtype=float)
>>> B = splu(A)
>>> x = np.array([1., 2., 3.], dtype=float)
>>> B.solve(x)
array([ 1. , -3. , -1.5])
>>> A.dot(B.solve(x))
array([ 1., 2., 3.])
>>> B.solve(A.dot(x))
array([ 1., 2., 3.])
"""
if is_pydata_spmatrix(A):
csc_construct_func = lambda *a, cls=type(A): cls(csc_matrix(*a))
A = A.to_scipy_sparse().tocsc()
else:
csc_construct_func = csc_matrix
if not isspmatrix_csc(A):
A = csc_matrix(A)
warn('splu requires CSC matrix format', SparseEfficiencyWarning)
# sum duplicates for non-canonical format
A.sum_duplicates()
A = A.asfptype() # upcast to a floating point format
M, N = A.shape
if (M != N):
raise ValueError("can only factor square matrices") # is this true?
_options = dict(DiagPivotThresh=diag_pivot_thresh, ColPerm=permc_spec,
PanelSize=panel_size, Relax=relax)
if options is not None:
_options.update(options)
# Ensure that no column permutations are applied
if (_options["ColPerm"] == "NATURAL"):
_options["SymmetricMode"] = True
return _superlu.gstrf(N, A.nnz, A.data, A.indices, A.indptr,
csc_construct_func=csc_construct_func,
ilu=False, options=_options)
def spilu(A, drop_tol=None, fill_factor=None, drop_rule=None, permc_spec=None,
diag_pivot_thresh=None, relax=None, panel_size=None, options=None):
"""
Compute an incomplete LU decomposition for a sparse, square matrix.
The resulting object is an approximation to the inverse of `A`.
Parameters
----------
A : (N, N) array_like
Sparse matrix to factorize
drop_tol : float, optional
Drop tolerance (0 <= tol <= 1) for an incomplete LU decomposition.
(default: 1e-4)
fill_factor : float, optional
Specifies the fill ratio upper bound (>= 1.0) for ILU. (default: 10)
drop_rule : str, optional
Comma-separated string of drop rules to use.
Available rules: ``basic``, ``prows``, ``column``, ``area``,
``secondary``, ``dynamic``, ``interp``. (Default: ``basic,area``)
See SuperLU documentation for details.
Remaining other options
Same as for `splu`
Returns
-------
invA_approx : scipy.sparse.linalg.SuperLU
Object, which has a ``solve`` method.
See also
--------
splu : complete LU decomposition
Notes
-----
To improve the better approximation to the inverse, you may need to
increase `fill_factor` AND decrease `drop_tol`.
This function uses the SuperLU library.
Examples
--------
>>> from scipy.sparse import csc_matrix
>>> from scipy.sparse.linalg import spilu
>>> A = csc_matrix([[1., 0., 0.], [5., 0., 2.], [0., -1., 0.]], dtype=float)
>>> B = spilu(A)
>>> x = np.array([1., 2., 3.], dtype=float)
>>> B.solve(x)
array([ 1. , -3. , -1.5])
>>> A.dot(B.solve(x))
array([ 1., 2., 3.])
>>> B.solve(A.dot(x))
array([ 1., 2., 3.])
"""
if is_pydata_spmatrix(A):
csc_construct_func = lambda *a, cls=type(A): cls(csc_matrix(*a))
A = A.to_scipy_sparse().tocsc()
else:
csc_construct_func = csc_matrix
if not isspmatrix_csc(A):
A = csc_matrix(A)
warn('splu requires CSC matrix format', SparseEfficiencyWarning)
# sum duplicates for non-canonical format
A.sum_duplicates()
A = A.asfptype() # upcast to a floating point format
M, N = A.shape
if (M != N):
raise ValueError("can only factor square matrices") # is this true?
_options = dict(ILU_DropRule=drop_rule, ILU_DropTol=drop_tol,
ILU_FillFactor=fill_factor,
DiagPivotThresh=diag_pivot_thresh, ColPerm=permc_spec,
PanelSize=panel_size, Relax=relax)
if options is not None:
_options.update(options)
# Ensure that no column permutations are applied
if (_options["ColPerm"] == "NATURAL"):
_options["SymmetricMode"] = True
return _superlu.gstrf(N, A.nnz, A.data, A.indices, A.indptr,
csc_construct_func=csc_construct_func,
ilu=True, options=_options)
def factorized(A):
"""
Return a function for solving a sparse linear system, with A pre-factorized.
Parameters
----------
A : (N, N) array_like
Input.
Returns
-------
solve : callable
To solve the linear system of equations given in `A`, the `solve`
callable should be passed an ndarray of shape (N,).
Examples
--------
>>> from scipy.sparse.linalg import factorized
>>> A = np.array([[ 3. , 2. , -1. ],
... [ 2. , -2. , 4. ],
... [-1. , 0.5, -1. ]])
>>> solve = factorized(A) # Makes LU decomposition.
>>> rhs1 = np.array([1, -2, 0])
>>> solve(rhs1) # Uses the LU factors.
array([ 1., -2., -2.])
"""
if is_pydata_spmatrix(A):
A = A.to_scipy_sparse().tocsc()
if useUmfpack:
if noScikit:
raise RuntimeError('Scikits.umfpack not installed.')
if not isspmatrix_csc(A):
A = csc_matrix(A)
warn('splu requires CSC matrix format', SparseEfficiencyWarning)
A = A.asfptype() # upcast to a floating point format
if A.dtype.char not in 'dD':
raise ValueError("convert matrix data to double, please, using"
" .astype(), or set linsolve.useUmfpack = False")
umf_family, A = _get_umf_family(A)
umf = umfpack.UmfpackContext(umf_family)
# Make LU decomposition.
umf.numeric(A)
def solve(b):
return umf.solve(umfpack.UMFPACK_A, A, b, autoTranspose=True)
return solve
else:
return splu(A).solve
def spsolve_triangular(A, b, lower=True, overwrite_A=False, overwrite_b=False,
unit_diagonal=False):
"""
Solve the equation `A x = b` for `x`, assuming A is a triangular matrix.
Parameters
----------
A : (M, M) sparse matrix
A sparse square triangular matrix. Should be in CSR format.
b : (M,) or (M, N) array_like
Right-hand side matrix in `A x = b`
lower : bool, optional
Whether `A` is a lower or upper triangular matrix.
Default is lower triangular matrix.
overwrite_A : bool, optional
Allow changing `A`. The indices of `A` are going to be sorted and zero
entries are going to be removed.
Enabling gives a performance gain. Default is False.
overwrite_b : bool, optional
Allow overwriting data in `b`.
Enabling gives a performance gain. Default is False.
If `overwrite_b` is True, it should be ensured that
`b` has an appropriate dtype to be able to store the result.
unit_diagonal : bool, optional
If True, diagonal elements of `a` are assumed to be 1 and will not be
referenced.
.. versionadded:: 1.4.0
Returns
-------
x : (M,) or (M, N) ndarray
Solution to the system `A x = b`. Shape of return matches shape of `b`.
Raises
------
LinAlgError
If `A` is singular or not triangular.
ValueError
If shape of `A` or shape of `b` do not match the requirements.
Notes
-----
.. versionadded:: 0.19.0
Examples
--------
>>> from scipy.sparse import csr_matrix
>>> from scipy.sparse.linalg import spsolve_triangular
>>> A = csr_matrix([[3, 0, 0], [1, -1, 0], [2, 0, 1]], dtype=float)
>>> B = np.array([[2, 0], [-1, 0], [2, 0]], dtype=float)
>>> x = spsolve_triangular(A, B)
>>> np.allclose(A.dot(x), B)
True
"""
if is_pydata_spmatrix(A):
A = A.to_scipy_sparse().tocsr()
# Check the input for correct type and format.
if not isspmatrix_csr(A):
warn('CSR matrix format is required. Converting to CSR matrix.',
SparseEfficiencyWarning)
A = csr_matrix(A)
elif not overwrite_A:
A = A.copy()
if A.shape[0] != A.shape[1]:
raise ValueError(
'A must be a square matrix but its shape is {}.'.format(A.shape))
# sum duplicates for non-canonical format
A.sum_duplicates()
b = np.asanyarray(b)
if b.ndim not in [1, 2]:
raise ValueError(
'b must have 1 or 2 dims but its shape is {}.'.format(b.shape))
if A.shape[0] != b.shape[0]:
raise ValueError(
'The size of the dimensions of A must be equal to '
'the size of the first dimension of b but the shape of A is '
'{} and the shape of b is {}.'.format(A.shape, b.shape))
# Init x as (a copy of) b.
x_dtype = np.result_type(A.data, b, np.float64)
if overwrite_b:
if np.can_cast(b.dtype, x_dtype, casting='same_kind'):
x = b
else:
raise ValueError(
'Cannot overwrite b (dtype {}) with result '
'of type {}.'.format(b.dtype, x_dtype))
else:
x = b.astype(x_dtype, copy=True)
# Choose forward or backward order.
if lower:
row_indices = range(len(b))
else:
row_indices = range(len(b) - 1, -1, -1)
# Fill x iteratively.
for i in row_indices:
# Get indices for i-th row.
indptr_start = A.indptr[i]
indptr_stop = A.indptr[i + 1]
if lower:
A_diagonal_index_row_i = indptr_stop - 1
A_off_diagonal_indices_row_i = slice(indptr_start, indptr_stop - 1)
else:
A_diagonal_index_row_i = indptr_start
A_off_diagonal_indices_row_i = slice(indptr_start + 1, indptr_stop)
# Check regularity and triangularity of A.
if not unit_diagonal and (indptr_stop <= indptr_start
or A.indices[A_diagonal_index_row_i] < i):
raise LinAlgError(
'A is singular: diagonal {} is zero.'.format(i))
if A.indices[A_diagonal_index_row_i] > i:
raise LinAlgError(
'A is not triangular: A[{}, {}] is nonzero.'
''.format(i, A.indices[A_diagonal_index_row_i]))
# Incorporate off-diagonal entries.
A_column_indices_in_row_i = A.indices[A_off_diagonal_indices_row_i]
A_values_in_row_i = A.data[A_off_diagonal_indices_row_i]
x[i] -= np.dot(x[A_column_indices_in_row_i].T, A_values_in_row_i)
# Compute i-th entry of x.
if not unit_diagonal:
x[i] /= A.data[A_diagonal_index_row_i]
return x

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from os.path import join, dirname
import sys
import glob
def configuration(parent_package='',top_path=None):
from numpy.distutils.misc_util import Configuration
from scipy._build_utils.system_info import get_info
from scipy._build_utils import numpy_nodepr_api
config = Configuration('dsolve',parent_package,top_path)
config.add_data_dir('tests')
lapack_opt = get_info('lapack_opt',notfound_action=2)
if sys.platform == 'win32':
superlu_defs = [('NO_TIMER',1)]
else:
superlu_defs = []
superlu_defs.append(('USE_VENDOR_BLAS',1))
superlu_src = join(dirname(__file__), 'SuperLU', 'SRC')
sources = sorted(glob.glob(join(superlu_src, '*.c')))
headers = list(glob.glob(join(superlu_src, '*.h')))
config.add_library('superlu_src',
sources=sources,
macros=superlu_defs,
include_dirs=[superlu_src],
)
# Extension
ext_sources = ['_superlumodule.c',
'_superlu_utils.c',
'_superluobject.c']
config.add_extension('_superlu',
sources=ext_sources,
libraries=['superlu_src'],
depends=(sources + headers),
extra_info=lapack_opt,
**numpy_nodepr_api
)
# Add license files
config.add_data_files('SuperLU/License.txt')
return config
if __name__ == '__main__':
from numpy.distutils.core import setup
setup(**configuration(top_path='').todict())

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import sys
import threading
import numpy as np
from numpy import array, finfo, arange, eye, all, unique, ones, dot
import numpy.random as random
from numpy.testing import (
assert_array_almost_equal, assert_almost_equal,
assert_equal, assert_array_equal, assert_, assert_allclose,
assert_warns, suppress_warnings)
import pytest
from pytest import raises as assert_raises
import scipy.linalg
from scipy.linalg import norm, inv
from scipy.sparse import (spdiags, SparseEfficiencyWarning, csc_matrix,
csr_matrix, identity, isspmatrix, dok_matrix, lil_matrix, bsr_matrix)
from scipy.sparse.linalg import SuperLU
from scipy.sparse.linalg.dsolve import (spsolve, use_solver, splu, spilu,
MatrixRankWarning, _superlu, spsolve_triangular, factorized)
import scipy.sparse
from scipy._lib._testutils import check_free_memory
sup_sparse_efficiency = suppress_warnings()
sup_sparse_efficiency.filter(SparseEfficiencyWarning)
# scikits.umfpack is not a SciPy dependency but it is optionally used in
# dsolve, so check whether it's available
try:
import scikits.umfpack as umfpack
has_umfpack = True
except ImportError:
has_umfpack = False
def toarray(a):
if isspmatrix(a):
return a.toarray()
else:
return a
def setup_bug_8278():
N = 2 ** 6
h = 1/N
Ah1D = scipy.sparse.diags([-1, 2, -1], [-1, 0, 1],
shape=(N-1, N-1))/(h**2)
eyeN = scipy.sparse.eye(N - 1)
A = (scipy.sparse.kron(eyeN, scipy.sparse.kron(eyeN, Ah1D))
+ scipy.sparse.kron(eyeN, scipy.sparse.kron(Ah1D, eyeN))
+ scipy.sparse.kron(Ah1D, scipy.sparse.kron(eyeN, eyeN)))
b = np.random.rand((N-1)**3)
return A, b
class TestFactorized(object):
def setup_method(self):
n = 5
d = arange(n) + 1
self.n = n
self.A = spdiags((d, 2*d, d[::-1]), (-3, 0, 5), n, n).tocsc()
random.seed(1234)
def _check_singular(self):
A = csc_matrix((5,5), dtype='d')
b = ones(5)
assert_array_almost_equal(0. * b, factorized(A)(b))
def _check_non_singular(self):
# Make a diagonal dominant, to make sure it is not singular
n = 5
a = csc_matrix(random.rand(n, n))
b = ones(n)
expected = splu(a).solve(b)
assert_array_almost_equal(factorized(a)(b), expected)
def test_singular_without_umfpack(self):
use_solver(useUmfpack=False)
with assert_raises(RuntimeError, match="Factor is exactly singular"):
self._check_singular()
@pytest.mark.skipif(not has_umfpack, reason="umfpack not available")
def test_singular_with_umfpack(self):
use_solver(useUmfpack=True)
with suppress_warnings() as sup:
sup.filter(RuntimeWarning, "divide by zero encountered in double_scalars")
assert_warns(umfpack.UmfpackWarning, self._check_singular)
def test_non_singular_without_umfpack(self):
use_solver(useUmfpack=False)
self._check_non_singular()
@pytest.mark.skipif(not has_umfpack, reason="umfpack not available")
def test_non_singular_with_umfpack(self):
use_solver(useUmfpack=True)
self._check_non_singular()
def test_cannot_factorize_nonsquare_matrix_without_umfpack(self):
use_solver(useUmfpack=False)
msg = "can only factor square matrices"
with assert_raises(ValueError, match=msg):
factorized(self.A[:, :4])
@pytest.mark.skipif(not has_umfpack, reason="umfpack not available")
def test_factorizes_nonsquare_matrix_with_umfpack(self):
use_solver(useUmfpack=True)
# does not raise
factorized(self.A[:,:4])
def test_call_with_incorrectly_sized_matrix_without_umfpack(self):
use_solver(useUmfpack=False)
solve = factorized(self.A)
b = random.rand(4)
B = random.rand(4, 3)
BB = random.rand(self.n, 3, 9)
with assert_raises(ValueError, match="is of incompatible size"):
solve(b)
with assert_raises(ValueError, match="is of incompatible size"):
solve(B)
with assert_raises(ValueError,
match="object too deep for desired array"):
solve(BB)
@pytest.mark.skipif(not has_umfpack, reason="umfpack not available")
def test_call_with_incorrectly_sized_matrix_with_umfpack(self):
use_solver(useUmfpack=True)
solve = factorized(self.A)
b = random.rand(4)
B = random.rand(4, 3)
BB = random.rand(self.n, 3, 9)
# does not raise
solve(b)
msg = "object too deep for desired array"
with assert_raises(ValueError, match=msg):
solve(B)
with assert_raises(ValueError, match=msg):
solve(BB)
def test_call_with_cast_to_complex_without_umfpack(self):
use_solver(useUmfpack=False)
solve = factorized(self.A)
b = random.rand(4)
for t in [np.complex64, np.complex128]:
with assert_raises(TypeError, match="Cannot cast array data"):
solve(b.astype(t))
@pytest.mark.skipif(not has_umfpack, reason="umfpack not available")
def test_call_with_cast_to_complex_with_umfpack(self):
use_solver(useUmfpack=True)
solve = factorized(self.A)
b = random.rand(4)
for t in [np.complex64, np.complex128]:
assert_warns(np.ComplexWarning, solve, b.astype(t))
@pytest.mark.skipif(not has_umfpack, reason="umfpack not available")
def test_assume_sorted_indices_flag(self):
# a sparse matrix with unsorted indices
unsorted_inds = np.array([2, 0, 1, 0])
data = np.array([10, 16, 5, 0.4])
indptr = np.array([0, 1, 2, 4])
A = csc_matrix((data, unsorted_inds, indptr), (3, 3))
b = ones(3)
# should raise when incorrectly assuming indices are sorted
use_solver(useUmfpack=True, assumeSortedIndices=True)
with assert_raises(RuntimeError,
match="UMFPACK_ERROR_invalid_matrix"):
factorized(A)
# should sort indices and succeed when not assuming indices are sorted
use_solver(useUmfpack=True, assumeSortedIndices=False)
expected = splu(A.copy()).solve(b)
assert_equal(A.has_sorted_indices, 0)
assert_array_almost_equal(factorized(A)(b), expected)
@pytest.mark.slow
@pytest.mark.skipif(not has_umfpack, reason="umfpack not available")
def test_bug_8278(self):
check_free_memory(8000)
use_solver(useUmfpack=True)
A, b = setup_bug_8278()
A = A.tocsc()
f = factorized(A)
x = f(b)
assert_array_almost_equal(A @ x, b)
class TestLinsolve(object):
def setup_method(self):
use_solver(useUmfpack=False)
def test_singular(self):
A = csc_matrix((5,5), dtype='d')
b = array([1, 2, 3, 4, 5],dtype='d')
with suppress_warnings() as sup:
sup.filter(MatrixRankWarning, "Matrix is exactly singular")
x = spsolve(A, b)
assert_(not np.isfinite(x).any())
def test_singular_gh_3312(self):
# "Bad" test case that leads SuperLU to call LAPACK with invalid
# arguments. Check that it fails moderately gracefully.
ij = np.array([(17, 0), (17, 6), (17, 12), (10, 13)], dtype=np.int32)
v = np.array([0.284213, 0.94933781, 0.15767017, 0.38797296])
A = csc_matrix((v, ij.T), shape=(20, 20))
b = np.arange(20)
try:
# should either raise a runtimeerror or return value
# appropriate for singular input
x = spsolve(A, b)
assert_(not np.isfinite(x).any())
except RuntimeError:
pass
def test_twodiags(self):
A = spdiags([[1, 2, 3, 4, 5], [6, 5, 8, 9, 10]], [0, 1], 5, 5)
b = array([1, 2, 3, 4, 5])
# condition number of A
cond_A = norm(A.todense(),2) * norm(inv(A.todense()),2)
for t in ['f','d','F','D']:
eps = finfo(t).eps # floating point epsilon
b = b.astype(t)
for format in ['csc','csr']:
Asp = A.astype(t).asformat(format)
x = spsolve(Asp,b)
assert_(norm(b - Asp*x) < 10 * cond_A * eps)
def test_bvector_smoketest(self):
Adense = array([[0., 1., 1.],
[1., 0., 1.],
[0., 0., 1.]])
As = csc_matrix(Adense)
random.seed(1234)
x = random.randn(3)
b = As*x
x2 = spsolve(As, b)
assert_array_almost_equal(x, x2)
def test_bmatrix_smoketest(self):
Adense = array([[0., 1., 1.],
[1., 0., 1.],
[0., 0., 1.]])
As = csc_matrix(Adense)
random.seed(1234)
x = random.randn(3, 4)
Bdense = As.dot(x)
Bs = csc_matrix(Bdense)
x2 = spsolve(As, Bs)
assert_array_almost_equal(x, x2.todense())
@sup_sparse_efficiency
def test_non_square(self):
# A is not square.
A = ones((3, 4))
b = ones((4, 1))
assert_raises(ValueError, spsolve, A, b)
# A2 and b2 have incompatible shapes.
A2 = csc_matrix(eye(3))
b2 = array([1.0, 2.0])
assert_raises(ValueError, spsolve, A2, b2)
@sup_sparse_efficiency
def test_example_comparison(self):
row = array([0,0,1,2,2,2])
col = array([0,2,2,0,1,2])
data = array([1,2,3,-4,5,6])
sM = csr_matrix((data,(row,col)), shape=(3,3), dtype=float)
M = sM.todense()
row = array([0,0,1,1,0,0])
col = array([0,2,1,1,0,0])
data = array([1,1,1,1,1,1])
sN = csr_matrix((data, (row,col)), shape=(3,3), dtype=float)
N = sN.todense()
sX = spsolve(sM, sN)
X = scipy.linalg.solve(M, N)
assert_array_almost_equal(X, sX.todense())
@sup_sparse_efficiency
@pytest.mark.skipif(not has_umfpack, reason="umfpack not available")
def test_shape_compatibility(self):
use_solver(useUmfpack=True)
A = csc_matrix([[1., 0], [0, 2]])
bs = [
[1, 6],
array([1, 6]),
[[1], [6]],
array([[1], [6]]),
csc_matrix([[1], [6]]),
csr_matrix([[1], [6]]),
dok_matrix([[1], [6]]),
bsr_matrix([[1], [6]]),
array([[1., 2., 3.], [6., 8., 10.]]),
csc_matrix([[1., 2., 3.], [6., 8., 10.]]),
csr_matrix([[1., 2., 3.], [6., 8., 10.]]),
dok_matrix([[1., 2., 3.], [6., 8., 10.]]),
bsr_matrix([[1., 2., 3.], [6., 8., 10.]]),
]
for b in bs:
x = np.linalg.solve(A.toarray(), toarray(b))
for spmattype in [csc_matrix, csr_matrix, dok_matrix, lil_matrix]:
x1 = spsolve(spmattype(A), b, use_umfpack=True)
x2 = spsolve(spmattype(A), b, use_umfpack=False)
# check solution
if x.ndim == 2 and x.shape[1] == 1:
# interprets also these as "vectors"
x = x.ravel()
assert_array_almost_equal(toarray(x1), x, err_msg=repr((b, spmattype, 1)))
assert_array_almost_equal(toarray(x2), x, err_msg=repr((b, spmattype, 2)))
# dense vs. sparse output ("vectors" are always dense)
if isspmatrix(b) and x.ndim > 1:
assert_(isspmatrix(x1), repr((b, spmattype, 1)))
assert_(isspmatrix(x2), repr((b, spmattype, 2)))
else:
assert_(isinstance(x1, np.ndarray), repr((b, spmattype, 1)))
assert_(isinstance(x2, np.ndarray), repr((b, spmattype, 2)))
# check output shape
if x.ndim == 1:
# "vector"
assert_equal(x1.shape, (A.shape[1],))
assert_equal(x2.shape, (A.shape[1],))
else:
# "matrix"
assert_equal(x1.shape, x.shape)
assert_equal(x2.shape, x.shape)
A = csc_matrix((3, 3))
b = csc_matrix((1, 3))
assert_raises(ValueError, spsolve, A, b)
@sup_sparse_efficiency
def test_ndarray_support(self):
A = array([[1., 2.], [2., 0.]])
x = array([[1., 1.], [0.5, -0.5]])
b = array([[2., 0.], [2., 2.]])
assert_array_almost_equal(x, spsolve(A, b))
def test_gssv_badinput(self):
N = 10
d = arange(N) + 1.0
A = spdiags((d, 2*d, d[::-1]), (-3, 0, 5), N, N)
for spmatrix in (csc_matrix, csr_matrix):
A = spmatrix(A)
b = np.arange(N)
def not_c_contig(x):
return x.repeat(2)[::2]
def not_1dim(x):
return x[:,None]
def bad_type(x):
return x.astype(bool)
def too_short(x):
return x[:-1]
badops = [not_c_contig, not_1dim, bad_type, too_short]
for badop in badops:
msg = "%r %r" % (spmatrix, badop)
# Not C-contiguous
assert_raises((ValueError, TypeError), _superlu.gssv,
N, A.nnz, badop(A.data), A.indices, A.indptr,
b, int(spmatrix == csc_matrix), err_msg=msg)
assert_raises((ValueError, TypeError), _superlu.gssv,
N, A.nnz, A.data, badop(A.indices), A.indptr,
b, int(spmatrix == csc_matrix), err_msg=msg)
assert_raises((ValueError, TypeError), _superlu.gssv,
N, A.nnz, A.data, A.indices, badop(A.indptr),
b, int(spmatrix == csc_matrix), err_msg=msg)
def test_sparsity_preservation(self):
ident = csc_matrix([
[1, 0, 0],
[0, 1, 0],
[0, 0, 1]])
b = csc_matrix([
[0, 1],
[1, 0],
[0, 0]])
x = spsolve(ident, b)
assert_equal(ident.nnz, 3)
assert_equal(b.nnz, 2)
assert_equal(x.nnz, 2)
assert_allclose(x.A, b.A, atol=1e-12, rtol=1e-12)
def test_dtype_cast(self):
A_real = scipy.sparse.csr_matrix([[1, 2, 0],
[0, 0, 3],
[4, 0, 5]])
A_complex = scipy.sparse.csr_matrix([[1, 2, 0],
[0, 0, 3],
[4, 0, 5 + 1j]])
b_real = np.array([1,1,1])
b_complex = np.array([1,1,1]) + 1j*np.array([1,1,1])
x = spsolve(A_real, b_real)
assert_(np.issubdtype(x.dtype, np.floating))
x = spsolve(A_real, b_complex)
assert_(np.issubdtype(x.dtype, np.complexfloating))
x = spsolve(A_complex, b_real)
assert_(np.issubdtype(x.dtype, np.complexfloating))
x = spsolve(A_complex, b_complex)
assert_(np.issubdtype(x.dtype, np.complexfloating))
@pytest.mark.slow
@pytest.mark.skipif(not has_umfpack, reason="umfpack not available")
def test_bug_8278(self):
check_free_memory(8000)
use_solver(useUmfpack=True)
A, b = setup_bug_8278()
x = spsolve(A, b)
assert_array_almost_equal(A @ x, b)
class TestSplu(object):
def setup_method(self):
use_solver(useUmfpack=False)
n = 40
d = arange(n) + 1
self.n = n
self.A = spdiags((d, 2*d, d[::-1]), (-3, 0, 5), n, n)
random.seed(1234)
def _smoketest(self, spxlu, check, dtype):
if np.issubdtype(dtype, np.complexfloating):
A = self.A + 1j*self.A.T
else:
A = self.A
A = A.astype(dtype)
lu = spxlu(A)
rng = random.RandomState(1234)
# Input shapes
for k in [None, 1, 2, self.n, self.n+2]:
msg = "k=%r" % (k,)
if k is None:
b = rng.rand(self.n)
else:
b = rng.rand(self.n, k)
if np.issubdtype(dtype, np.complexfloating):
b = b + 1j*rng.rand(*b.shape)
b = b.astype(dtype)
x = lu.solve(b)
check(A, b, x, msg)
x = lu.solve(b, 'T')
check(A.T, b, x, msg)
x = lu.solve(b, 'H')
check(A.T.conj(), b, x, msg)
@sup_sparse_efficiency
def test_splu_smoketest(self):
self._internal_test_splu_smoketest()
def _internal_test_splu_smoketest(self):
# Check that splu works at all
def check(A, b, x, msg=""):
eps = np.finfo(A.dtype).eps
r = A * x
assert_(abs(r - b).max() < 1e3*eps, msg)
self._smoketest(splu, check, np.float32)
self._smoketest(splu, check, np.float64)
self._smoketest(splu, check, np.complex64)
self._smoketest(splu, check, np.complex128)
@sup_sparse_efficiency
def test_spilu_smoketest(self):
self._internal_test_spilu_smoketest()
def _internal_test_spilu_smoketest(self):
errors = []
def check(A, b, x, msg=""):
r = A * x
err = abs(r - b).max()
assert_(err < 1e-2, msg)
if b.dtype in (np.float64, np.complex128):
errors.append(err)
self._smoketest(spilu, check, np.float32)
self._smoketest(spilu, check, np.float64)
self._smoketest(spilu, check, np.complex64)
self._smoketest(spilu, check, np.complex128)
assert_(max(errors) > 1e-5)
@sup_sparse_efficiency
def test_spilu_drop_rule(self):
# Test passing in the drop_rule argument to spilu.
A = identity(2)
rules = [
b'basic,area'.decode('ascii'), # unicode
b'basic,area', # ascii
[b'basic', b'area'.decode('ascii')]
]
for rule in rules:
# Argument should be accepted
assert_(isinstance(spilu(A, drop_rule=rule), SuperLU))
def test_splu_nnz0(self):
A = csc_matrix((5,5), dtype='d')
assert_raises(RuntimeError, splu, A)
def test_spilu_nnz0(self):
A = csc_matrix((5,5), dtype='d')
assert_raises(RuntimeError, spilu, A)
def test_splu_basic(self):
# Test basic splu functionality.
n = 30
rng = random.RandomState(12)
a = rng.rand(n, n)
a[a < 0.95] = 0
# First test with a singular matrix
a[:, 0] = 0
a_ = csc_matrix(a)
# Matrix is exactly singular
assert_raises(RuntimeError, splu, a_)
# Make a diagonal dominant, to make sure it is not singular
a += 4*eye(n)
a_ = csc_matrix(a)
lu = splu(a_)
b = ones(n)
x = lu.solve(b)
assert_almost_equal(dot(a, x), b)
def test_splu_perm(self):
# Test the permutation vectors exposed by splu.
n = 30
a = random.random((n, n))
a[a < 0.95] = 0
# Make a diagonal dominant, to make sure it is not singular
a += 4*eye(n)
a_ = csc_matrix(a)
lu = splu(a_)
# Check that the permutation indices do belong to [0, n-1].
for perm in (lu.perm_r, lu.perm_c):
assert_(all(perm > -1))
assert_(all(perm < n))
assert_equal(len(unique(perm)), len(perm))
# Now make a symmetric, and test that the two permutation vectors are
# the same
# Note: a += a.T relies on undefined behavior.
a = a + a.T
a_ = csc_matrix(a)
lu = splu(a_)
assert_array_equal(lu.perm_r, lu.perm_c)
@pytest.mark.parametrize("splu_fun, rtol", [(splu, 1e-7), (spilu, 1e-1)])
def test_natural_permc(self, splu_fun, rtol):
# Test that the "NATURAL" permc_spec does not permute the matrix
np.random.seed(42)
n = 500
p = 0.01
A = scipy.sparse.random(n, n, p)
x = np.random.rand(n)
# Make A diagonal dominant to make sure it is not singular
A += (n+1)*scipy.sparse.identity(n)
A_ = csc_matrix(A)
b = A_ @ x
# without permc_spec, permutation is not identity
lu = splu_fun(A_)
assert_(np.any(lu.perm_c != np.arange(n)))
# with permc_spec="NATURAL", permutation is identity
lu = splu_fun(A_, permc_spec="NATURAL")
assert_array_equal(lu.perm_c, np.arange(n))
# Also, lu decomposition is valid
x2 = lu.solve(b)
assert_allclose(x, x2, rtol=rtol)
@pytest.mark.skipif(not hasattr(sys, 'getrefcount'), reason="no sys.getrefcount")
def test_lu_refcount(self):
# Test that we are keeping track of the reference count with splu.
n = 30
a = random.random((n, n))
a[a < 0.95] = 0
# Make a diagonal dominant, to make sure it is not singular
a += 4*eye(n)
a_ = csc_matrix(a)
lu = splu(a_)
# And now test that we don't have a refcount bug
rc = sys.getrefcount(lu)
for attr in ('perm_r', 'perm_c'):
perm = getattr(lu, attr)
assert_equal(sys.getrefcount(lu), rc + 1)
del perm
assert_equal(sys.getrefcount(lu), rc)
def test_bad_inputs(self):
A = self.A.tocsc()
assert_raises(ValueError, splu, A[:,:4])
assert_raises(ValueError, spilu, A[:,:4])
for lu in [splu(A), spilu(A)]:
b = random.rand(42)
B = random.rand(42, 3)
BB = random.rand(self.n, 3, 9)
assert_raises(ValueError, lu.solve, b)
assert_raises(ValueError, lu.solve, B)
assert_raises(ValueError, lu.solve, BB)
assert_raises(TypeError, lu.solve,
b.astype(np.complex64))
assert_raises(TypeError, lu.solve,
b.astype(np.complex128))
@sup_sparse_efficiency
def test_superlu_dlamch_i386_nan(self):
# SuperLU 4.3 calls some functions returning floats without
# declaring them. On i386@linux call convention, this fails to
# clear floating point registers after call. As a result, NaN
# can appear in the next floating point operation made.
#
# Here's a test case that triggered the issue.
n = 8
d = np.arange(n) + 1
A = spdiags((d, 2*d, d[::-1]), (-3, 0, 5), n, n)
A = A.astype(np.float32)
spilu(A)
A = A + 1j*A
B = A.A
assert_(not np.isnan(B).any())
@sup_sparse_efficiency
def test_lu_attr(self):
def check(dtype, complex_2=False):
A = self.A.astype(dtype)
if complex_2:
A = A + 1j*A.T
n = A.shape[0]
lu = splu(A)
# Check that the decomposition is as advertized
Pc = np.zeros((n, n))
Pc[np.arange(n), lu.perm_c] = 1
Pr = np.zeros((n, n))
Pr[lu.perm_r, np.arange(n)] = 1
Ad = A.toarray()
lhs = Pr.dot(Ad).dot(Pc)
rhs = (lu.L * lu.U).toarray()
eps = np.finfo(dtype).eps
assert_allclose(lhs, rhs, atol=100*eps)
check(np.float32)
check(np.float64)
check(np.complex64)
check(np.complex128)
check(np.complex64, True)
check(np.complex128, True)
@pytest.mark.slow
@sup_sparse_efficiency
def test_threads_parallel(self):
oks = []
def worker():
try:
self.test_splu_basic()
self._internal_test_splu_smoketest()
self._internal_test_spilu_smoketest()
oks.append(True)
except Exception:
pass
threads = [threading.Thread(target=worker)
for k in range(20)]
for t in threads:
t.start()
for t in threads:
t.join()
assert_equal(len(oks), 20)
class TestSpsolveTriangular(object):
def setup_method(self):
use_solver(useUmfpack=False)
def test_singular(self):
n = 5
A = csr_matrix((n, n))
b = np.arange(n)
for lower in (True, False):
assert_raises(scipy.linalg.LinAlgError, spsolve_triangular, A, b, lower=lower)
@sup_sparse_efficiency
def test_bad_shape(self):
# A is not square.
A = np.zeros((3, 4))
b = ones((4, 1))
assert_raises(ValueError, spsolve_triangular, A, b)
# A2 and b2 have incompatible shapes.
A2 = csr_matrix(eye(3))
b2 = array([1.0, 2.0])
assert_raises(ValueError, spsolve_triangular, A2, b2)
@sup_sparse_efficiency
def test_input_types(self):
A = array([[1., 0.], [1., 2.]])
b = array([[2., 0.], [2., 2.]])
for matrix_type in (array, csc_matrix, csr_matrix):
x = spsolve_triangular(matrix_type(A), b, lower=True)
assert_array_almost_equal(A.dot(x), b)
@pytest.mark.slow
@sup_sparse_efficiency
def test_random(self):
def random_triangle_matrix(n, lower=True):
A = scipy.sparse.random(n, n, density=0.1, format='coo')
if lower:
A = scipy.sparse.tril(A)
else:
A = scipy.sparse.triu(A)
A = A.tocsr(copy=False)
for i in range(n):
A[i, i] = np.random.rand() + 1
return A
np.random.seed(1234)
for lower in (True, False):
for n in (10, 10**2, 10**3):
A = random_triangle_matrix(n, lower=lower)
for m in (1, 10):
for b in (np.random.rand(n, m),
np.random.randint(-9, 9, (n, m)),
np.random.randint(-9, 9, (n, m)) +
np.random.randint(-9, 9, (n, m)) * 1j):
x = spsolve_triangular(A, b, lower=lower)
assert_array_almost_equal(A.dot(x), b)
x = spsolve_triangular(A, b, lower=lower,
unit_diagonal=True)
A.setdiag(1)
assert_array_almost_equal(A.dot(x), b)