1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
|
#-------------------------------------------------------------------------------
# SPEX/Python/SPEXpy/lu_backslash.py: solve Ax=b using LU factorization
#-------------------------------------------------------------------------------
# SPEX: (c) 2022-2024, Christopher Lourenco, Jinhao Chen,
# Lorena Mejia Domenzain, Erick Moreno-Centeno, and Timothy A. Davis.
# All Rights Reserved.
# SPDX-License-Identifier: GPL-2.0-or-later or LGPL-3.0-or-later
#------------------------------------------------------------------------------
from .Options import Options
from .SPEX_error import *
from .spex_connect import spex_connect
import scipy
from scipy.sparse import isspmatrix, isspmatrix_csc, linalg
def lu_backslash( A, b, options=Options('double', 'colamd')):
## A is a scipy.sparse(data must be float64) #technically it only needs to be numerical
## b is a numpy.array (data must be float64)
## options is a dictionary that specifies what tipe the solution should be, this by default is double
##--------------------------------------------------------------------------
## Verify inputs
##--------------------------------------------------------------------------
if not isspmatrix(A):
raise SPEX_error(determine_error(3))
## If the sparse input matrix is not in csc form, convert it into csc form
if not isspmatrix_csc(A):
A.tocsc()
# Check input shape
if A.shape[1]!=b.shape[0]:
raise SPEX_error(determine_error(3))
if options.ordering==None:
options.default_lu()
##--------------------------------------------------------------------------
## Call SPEX
##--------------------------------------------------------------------------
x=spex_connect(A,b,options.order(),options.charOut(),2) #2 calls lu
return x
|