def _buildMatrix(self, var, SparseMatrix, boundaryConditions=(), dt=1., equation=None):
"""Implicit portion considers
"""
mesh = var.getMesh()
id1, id2 = mesh._getAdjacentCellIDs()
interiorFaces = numerix.nonzero(mesh.getInteriorFaces())[0]
id1 = numerix.take(id1, interiorFaces)
id2 = numerix.take(id2, interiorFaces)
N = len(var)
b = numerix.zeros((N),'d')
L = SparseMatrix(size = N)
if equation is not None:
from fipy.tools.numerix import sign, add
self._diagonalSign.setValue(sign(add.reduce(equation.matrix.takeDiagonal())))
else:
self._diagonalSign.setValue(1)
weight = self._getWeight(mesh, equation=equation)
if weight.has_key('implicit'):
self._implicitBuildMatrix(SparseMatrix, L, id1, id2, b, weight['implicit'], mesh, boundaryConditions, interiorFaces, dt)
if weight.has_key('explicit'):
self._explicitBuildMatrix(SparseMatrix, var.getOld(), id1, id2, b, weight['explicit'], mesh, boundaryConditions, interiorFaces, dt)
return (L, b)
def _buildMatrix(self, var, SparseMatrix, boundaryConditions=(), dt=1., equation=None):
N = len(var)
b = numerix.zeros((N),'d')
L = SparseMatrix(size=N)
# The sign of the matrix diagonal doesn't seem likely to change
# after initialization, but who knows?
if equation is not None:
from fipy.tools.numerix import sign, add
self._diagonalSign.setValue(sign(add.reduce(equation.matrix.takeDiagonal())))
else:
self._diagonalSign.setValue(1)
coeffVectors = self._getCoeffVectors(var=var)
inline._optionalInline(self._buildMatrixIn, self._buildMatrixPy, L, var.getOld(), b, dt, coeffVectors)
return (L, b)