void EqnProperty::force_deriv_matrix(const FEMesh *mesh, const Element *element,
const Equation *eqn,
const ElementFuncNodeIterator &node,
const MasterPosition &pt, double time,
SmallSystem *eqndata) const
{
int nrows = eqndata->nrows();
int ncols = eqndata->ncols();
DoubleVec forceVec0(nrows), forceVec1(nrows);
SmallSystem eqndata0( nrows, ncols );
SmallSystem eqndata1( nrows, ncols );
// Get the current subproblem, to check if the fields are active
CSubProblem *subproblem = mesh->getCurrentSubProblem();
if ( !subproblem )
throw ErrProgrammingError("Current subproblem not defined",
__FILE__, __LINE__);
// Loop over all the fields (that the node might have)
for(std::vector<Field*>::size_type fi=0; fi<Field::all().size(); fi++)
{
Field *field = &( *Field::all()[fi] );
if (node.hasField( *field ) && field->is_active( subproblem ))
{
// Loop over field components
for(IteratorP fieldcomp=field->iterator(ALL_INDICES);
!fieldcomp.end(); ++fieldcomp)
{
DegreeOfFreedom *dof = (*field)(node, fieldcomp.integer());
double oldValue = dof->value( mesh );
// Scale eps by original value for robustness
double eps = max(min_eps, fabs(oldValue) * deriv_eps);
double upValue = oldValue + eps;
double dnValue = oldValue - eps;
// First compute forceVec0 = f(u-eps)
dof->setValue( mesh, dnValue );
force_value(mesh, element, eqn, pt, time, &eqndata0);
forceVec0 = eqndata0.forceVector();
// Now compute forceVec1 = f(u+eps)
dof->setValue( mesh, upValue );
force_value(mesh, element, eqn, pt, time, &eqndata1);
forceVec1 = eqndata1.forceVector();
dof->setValue( mesh, oldValue );
// Compute the numerical derivative: (f1 - f0) / (2*eps)
forceVec1 -= forceVec0;
forceVec1 /= (upValue - dnValue);
// Assign the derivative value to force_deriv_matrix
for(IteratorP eqncomp = eqn->iterator(); !eqncomp.end(); ++eqncomp)
eqndata->force_deriv_matrix_element( eqncomp, field, fieldcomp, node )
+= forceVec1[ eqncomp.integer() ];
zero( eqndata0.forceVector() );
zero( eqndata1.forceVector() );
} // loop over field components
} // end if (node.hasfield())
} // loop over all fields
} // end of force_deriv_matrix
void FluxProperty::flux_matrix(const FEMesh *mesh, const Element *element,
const ElementFuncNodeIterator &node,
const Flux *flux, const MasterPosition &pt,
double time, SmallSystem *fluxdata)
const
{
#ifdef _OPENMP
bool& recurse = recurse_flags[omp_get_thread_num()];
#endif
if(recurse) {
return;
}
recurse = true;
int nrows = fluxdata->nrows();
int ncols = fluxdata->ncols();
DoubleVec fluxVec0(nrows);
DoubleVec fluxVec1(nrows);
SmallSystem fluxdata0( nrows, ncols );
SmallSystem fluxdata1( nrows, ncols );
CSubProblem *subproblem = mesh->getCurrentSubProblem();
// Get the current subproblem, to check if the fields are active
if ( !subproblem )
throw ErrProgrammingError("Current subproblem not defined",
__FILE__, __LINE__);
// Loop over all the fields (that the node might have)
for (std::vector<Field*>::size_type fi=0; fi<Field::all().size(); fi++)
{
Field *field = &( *Field::all()[fi] );
if (node.hasField( *field ) && field->is_active( subproblem ))
{
// Loop over field components
for(IteratorP fieldcomp=field->iterator(ALL_INDICES);
!fieldcomp.end(); ++fieldcomp)
{
DegreeOfFreedom *dof = (*field)(node, fieldcomp.integer());
double oldValue = dof->value( mesh );
// Scale eps by original value for robustness
double eps = max(min_eps, fabs(oldValue)* deriv_eps);
double upValue = oldValue + eps;
double dnValue = oldValue - eps;
// First compute fluxVec0 = sigma(u-eps)
dof->setValue( mesh, dnValue );
static_flux_value(mesh, element, flux, pt, time, &fluxdata0);
fluxVec0 = fluxdata0.fluxVector();
// Now compute fluxVec1 = sigma(u+eps)
dof->setValue( mesh, upValue );
static_flux_value(mesh, element, flux, pt, time, &fluxdata1);
fluxVec1 = fluxdata1.fluxVector();
// Reset to original value!
dof->setValue( mesh, oldValue );
// Compute the numerical derivative: (fluxVec1 - fluxVec0) / 2*eps
fluxVec1 -= fluxVec0;
fluxVec1 /= (upValue - dnValue);
// Assign the derivative value to flux_matrix
for(IteratorP fluxcomp = flux->iterator(ALL_INDICES);
!fluxcomp.end(); ++fluxcomp)
fluxdata->stiffness_matrix_element( fluxcomp, field, fieldcomp, node )
+= fluxVec1[ fluxcomp.integer() ];
zero( fluxdata0.fluxVector() );
zero( fluxdata1.fluxVector() );
} // loop over field components
} // end if (node.hasfield())
} // loop over all fields
} // end of 'FluxProperty::flux_matrix'