# ____________________________________________________________________________________
#
# Pyomo: Python Optimization Modeling Objects
# Copyright (c) 2008-2026 National Technology and Engineering Solutions of Sandia, LLC
# Under the terms of Contract DE-NA0003525 with National Technology and Engineering
# Solutions of Sandia, LLC, the U.S. Government retains certain rights in this
# software. This software is distributed under the 3-clause BSD License.
# ____________________________________________________________________________________
from .base_linear_solver_interface import IPLinearSolverInterface
from pyomo.contrib.pynumero.linalg.base import LinearSolverResults
from scipy.linalg import eigvals
from scipy.sparse import spmatrix
from pyomo.contrib.pynumero.sparse import BlockMatrix
import logging
import numpy as np
from pyomo.contrib.pynumero.linalg.scipy_interface import ScipyLU
from typing import Union
[docs]
class ScipyInterface(ScipyLU, IPLinearSolverInterface):
@classmethod
def getLoggerName(cls):
return 'ScipyLU'
[docs]
def __init__(self, compute_inertia=False):
super(ScipyInterface, self).__init__()
self._inertia = None
self.compute_inertia = compute_inertia
self.logger = logging.getLogger('scipy')
self.logger.propagate = False
def do_numeric_factorization(
self, matrix: Union[spmatrix, BlockMatrix], raise_on_error: bool = True
) -> LinearSolverResults:
res = super(ScipyInterface, self).do_numeric_factorization(
matrix=matrix, raise_on_error=raise_on_error
)
if self.compute_inertia:
eig = eigvals(matrix.toarray())
pos_eig = np.count_nonzero((eig > 0))
neg_eigh = np.count_nonzero((eig < 0))
zero_eig = np.count_nonzero(eig == 0)
self._inertia = (pos_eig, neg_eigh, zero_eig)
return res
def get_inertia(self):
if self._inertia is None:
raise RuntimeError(
'The inertia was not computed during do_numeric_factorization. Set compute_inertia to True.'
)
return self._inertia