void QRDecomposition<T>::backSub(const VectorT& b, VectorT& x) const
{
if(x.n == 0) x.resize(QR.n);
Assert(QR.m == b.n);
Assert(QR.n == x.n);
/* compute rhs = Q^T b */
VectorT rhs;
QtMul(b,rhs);
if(QR.m == QR.n) {
/* Solve R x = rhs, storing x in-place */
UBackSubstitute(QR,rhs,x);
//UBackSubstitute(QR,x,x);
}
else if(QR.m > QR.n) {
//solve the top part of R x = rhs
MatrixT R1; R1.setRef(QR,0,0,1,1,QR.n,QR.n);
VectorT rhs1; rhs1.setRef(rhs,0,1,QR.n);
UBackSubstitute(R1,rhs1,x);
}
else {
cerr<<"What do we do with m < n?"<<endl;
MatrixPrinter mprint(QR); mprint.mode = MatrixPrinter::AsciiShade;
cerr<<mprint<<endl;
//solve the left part of R x = rhs
MatrixT R1; R1.setRef(QR,0,0,1,1,QR.m,QR.m);
VectorT x1; x1.setRef(x,0,1,QR.m);
UBackSubstitute(R1,rhs,x1);
getchar();
}
}
void operator()(LinPdeSysT const & pde_system,
SegmentT const & segment,
StorageType & storage,
MatrixT & system_matrix,
VectorT & load_vector)
{
typedef viennamath::equation equ_type;
typedef viennamath::expr expr_type;
typedef typename expr_type::interface_type interface_type;
typedef typename expr_type::numeric_type numeric_type;
typedef typename viennagrid::result_of::cell_tag<SegmentT>::type CellTag;
std::size_t map_index = viennafvm::create_mapping(pde_system, segment, storage);
system_matrix.clear();
system_matrix.resize(map_index, map_index, false);
load_vector.clear();
load_vector.resize(map_index);
for (std::size_t pde_index = 0; pde_index < pde_system.size(); ++pde_index)
{
#ifdef VIENNAFVM_DEBUG
std::cout << std::endl;
std::cout << "//" << std::endl;
std::cout << "// Equation " << pde_index << std::endl;
std::cout << "//" << std::endl;
#endif
assemble(pde_system, pde_index,
segment, storage,
system_matrix, load_vector);
} // for pde_index
} // functor
void RowEchelon<T>::backSub(VectorT& x) const
{
Assert(EB.n == 1);
Assert(EB.m == R.m);
x.resize(R.n);
VectorT b;
EB.getColRef(0,b);
Assert((int)firstEntry.size() == R.m+1);
x.setZero();
int m=R.m,n=R.n;
for(int i=m-1;i>=0;i--) {
VectorT ri; R.getRowRef(i,ri);
//solve to set R*x = b[i]
//calculate alpha = dot between rest of x[>ji] and R[i]
int ji=firstEntry[i];
if(ji == n) continue;
int ji2=firstEntry[i+1]; //(i+1==m?n:firstEntry[i+1]);
T alpha;
if(ji2 == n) alpha = Zero;
else {
VectorT rji2; rji2.setRef(ri,ji2,1,R.n-ji2);
VectorT xji2; xji2.setRef(x,ji2,1,R.n-ji2);
alpha = xji2.dot(rji2);
}
x[ji] = (b[i]-alpha)/ri[ji];
}
}
void SparseVectorTemplate<T>::get(VectorT& v) const
{
v.resize(this->n);
int k=0;
for(const_iterator i=this->begin();i!=this->end();i++) {
while(k < i->first) { v(k)=0; k++; }
v(k) = i->second;
k=i->first+1;
}
while(k < (int)this->n) { v(k)=0; k++; }
}
void DiagonalMatrixTemplate<T>::mulPseudoInverse(const VectorT& a, VectorT& b) const
{
if(BaseT::n != a.n) FatalError(MatrixError_ArgIncompatibleDimensions);
if(b.n == 0)
b.resize(this->n);
else if(b.n != this->n) FatalError(MatrixError_DestIncompatibleDimensions);
ItT v=this->begin();
VectorIterator<T> va=a.begin(),vb=b.begin();
for(int i=0; i<this->n; i++, v++,va++,vb++)
*vb = *va * PseudoInv(*v);
}
void SparseVectorCompressed<T>::get(VectorT& v) const
{
v.resize(n);
int i=0;
for(int k=0;k<num_entries;k++) {
for(;i<indices[k];i++)
v[i]=Zero;
v[i]=vals[k];
}
for(;i<this->n;i++)
v[i]=Zero;
}
void LDLDecomposition<T>::DBackSub(const VectorT& b, VectorT& x) const
{
x.resize(b.n);
Assert(b.n==x.n);
for(int i=0;i<x.n;i++) {
if(!FuzzyZero(LDL(i,i),zeroTolerance))
x(i) = b(i)/LDL(i,i);
else {
if(!FuzzyZero(b(i),zeroTolerance))
cerr<<"LDLDecomposition::DBackSub(): Warning, zero on the diagonal"<<endl;
x(i) = 0;
}
}
}
void SparseMatrixTemplate_RM<T>::mulTranspose(const VectorT& a,VectorT& x) const
{
if(x.n == 0) x.resize(n);
if(x.n != n) {
FatalError("Destination vector has incorrect dimensions");
}
if(a.n != m) {
FatalError("Source vector has incorrect dimensions");
}
x.setZero();
for(int i=0;i<m;i++) {
for(ConstRowIterator it=rows[i].begin();it!=rows[i].end();it++)
x(it->first) += it->second*a(i);
}
}
void SparseMatrixTemplate_RM<T>::mul(const VectorT& a,VectorT& x) const
{
if(x.n == 0) x.resize(m);
if(x.n != m) {
FatalError("Destination vector has incorrect dimensions");
}
if(a.n != n) {
FatalError("Source vector has incorrect dimensions");
}
for(int i=0;i<m;i++) {
T sum=0;
for(ConstRowIterator it=rows[i].begin();it!=rows[i].end();it++)
sum += it->second*a(it->first);
x(i) = sum;
}
}
void MatrixTemplate<T>::maddTranspose(const VectorT& a, VectorT& b) const
{
if(m != a.n)
{
RaiseErrorFmt(WHERE_AM_I,MatrixError_ArgIncompatibleDimensions);
}
if(b.n == 0)
{
b.resize(n);
}
else if(b.n != n)
{
RaiseErrorFmt(WHERE_AM_I,MatrixError_DestIncompatibleDimensions);
}
gen_array2d_vector_madd_transpose(b.getStart(),b.stride,
getStart(),istride,jstride,
a.getStart(),a.stride,
m, n);
}
bool LDLDecomposition<T>::DBackSub(const VectorT& b, VectorT& x) const
{
bool res=true;
x.resize(b.n);
Assert(b.n==x.n);
for(int i=0;i<x.n;i++) {
if(!FuzzyZero(LDL(i,i),zeroTolerance))
x(i) = b(i)/LDL(i,i);
else {
if(!FuzzyZero(b(i),zeroTolerance)) {
if(verbose >= 1)
LOG4CXX_ERROR(KrisLibrary::logger(),"LDLDecomposition::DBackSub(): Warning, zero on the diagonal, b("<<i<<")="<<b(i));
res = false;
x(i) = Sign(b(i))*Inf;
}
else
x(i) = 0;
}
}
return res;
}
void QRDecomposition<T>::leastSquares(const VectorT& b, VectorT& x, VectorT& residual) const
{
if(x.n == 0) x.resize(QR.n);
Assert(QR.m >= QR.n);
Assert(QR.m == b.n);
Assert(QR.n == x.n);
Assert(QR.m == residual.n);
MatrixT R;
R.setRef(QR,0,0,1,1,QR.n,QR.n);
VectorT c;
c.setRef(residual,0,1,QR.n);
/* compute rhs = Q^T b */
QtMul(b,residual);
/* Solve R x = rhs */
UBackSubstitute(R,c,x);
/* Compute residual = b - A x = Q (Q^T b - R x) */
c.setZero();
QMul(residual,residual);
}
void LDLDecomposition<T>::getD(VectorT& d) const
{
Assert(LDL.m == LDL.n);
d.resize(LDL.n);
LDL.getDiagCopy(0,d);
}
void LDLDecomposition<T>::LTBackSub(const VectorT& b, VectorT& x) const
{
Assert(b.n == LDL.n);
x.resize(LDL.n);
Lt1BackSubstitute(LDL,b,x);
}
void operator()(SystemType pde_system,
DomainType & domain,
MatrixT & system_matrix,
VectorT & load_vector
) const
{
typedef typename viennagrid::result_of::cell_tag<DomainType>::type CellTag;
typedef typename viennagrid::result_of::point<DomainType>::type PointType;
typedef typename viennagrid::result_of::element<DomainType, CellTag>::type CellType;
typedef typename viennagrid::result_of::element_range<DomainType, CellTag>::type CellContainer;
typedef typename viennagrid::result_of::iterator<CellContainer>::type CellIterator;
typedef typename SystemType::equation_type EquationType;
#ifdef VIENNAFEM_DEBUG
std::cout << "Strong form: " << pde_system.pde(0) << std::endl;
#endif
log_strong_form(pde_system);
EquationType weak_form_general = viennafem::make_weak_form(pde_system.pde(0));
#ifdef VIENNAFEM_DEBUG
std::cout << "* pde_solver::operator(): Using weak form general: " << weak_form_general << std::endl;
#endif
std::vector<EquationType> temp(1); temp[0] = weak_form_general;
log_weak_form(temp, pde_system);
EquationType weak_form = viennamath::apply_coordinate_system(viennamath::cartesian< PointType::dim >(), weak_form_general);
//EquationType weak_form = viennamath::apply_coordinate_system(viennamath::cartesian<Config::coordinate_system_tag::dim>(), weak_form_general);
temp[0] = weak_form;
log_coordinated_weak_form(temp, pde_system);
#ifdef VIENNAFEM_DEBUG
std::cout << "* pde_solver::operator(): Using weak form " << weak_form << std::endl;
std::cout << "* pde_solver::operator(): Write dt_dx coefficients" << std::endl;
#endif
typedef typename reference_cell_for_basis<CellTag, viennafem::lagrange_tag<1> >::type ReferenceCell;
//
// Create accessors for performance in the subsequent dt_dx_handler step
//
//viennafem::dtdx_assigner<DomainType, StorageType, ReferenceCell>::apply(domain, storage);
viennafem::dt_dx_handler<DomainType, StorageType, ReferenceCell> dt_dx_handler(domain, storage);
//fill with cell quantities
CellContainer cells = viennagrid::elements<CellType>(domain);
for (CellIterator cell_iter = cells.begin();
cell_iter != cells.end();
++cell_iter)
{
//cell_iter->print_short();
//viennadata::access<example_key, double>()(*cell_iter) = i;
//viennafem::dt_dx_handler<ReferenceCell>::apply(storage, *cell_iter);
dt_dx_handler(*cell_iter);
}
#ifdef VIENNAFEM_DEBUG
std::cout << "* pde_solver::operator(): Create Mapping:" << std::endl;
#endif
std::size_t map_index = create_mapping(storage, pde_system, domain);
#ifdef VIENNAFEM_DEBUG
std::cout << "* pde_solver::operator(): Assigned degrees of freedom in domain so far: " << map_index << std::endl;
#endif
// resize global system matrix and load vector if needed:
// TODO: This can be a performance bottleneck for large numbers of segments! (lots of resize operations...)
if (map_index > system_matrix.size1())
{
MatrixT temp = system_matrix;
////std::cout << "Resizing system matrix..." << std::endl;
system_matrix.resize(map_index, map_index, false);
system_matrix.clear();
system_matrix.resize(map_index, map_index, false);
for (typename MatrixT::iterator1 row_it = temp.begin1();
row_it != temp.end1();
++row_it)
{
for (typename MatrixT::iterator2 col_it = row_it.begin();
col_it != row_it.end();
++col_it)
system_matrix(col_it.index1(), col_it.index2()) = *col_it;
}
}
if (map_index > load_vector.size())
{
VectorT temp = load_vector;
#ifdef VIENNAFEM_DEBUG
std::cout << "Resizing load vector..." << std::endl;
#endif
load_vector.resize(map_index, false);
load_vector.clear();
load_vector.resize(map_index, false);
for (std::size_t i=0; i<temp.size(); ++i)
load_vector(i) = temp(i);
}
#ifdef VIENNAFEM_DEBUG
std::cout << "* pde_solver::operator(): Transform to reference element" << std::endl;
#endif
EquationType transformed_weak_form = viennafem::transform_to_reference_cell<CellType>(storage, weak_form, pde_system);
temp[0] = transformed_weak_form;
log_transformed_weak_form<CellType, StorageType>(temp, pde_system);
std::cout << "* pde_solver::operator(): Transformed weak form:" << std::endl;
std::cout << transformed_weak_form << std::endl;
//std::cout << std::endl;
#ifdef VIENNAFEM_DEBUG
std::cout << "* pde_solver::operator(): Assemble system" << std::endl;
#endif
typedef detail::equation_wrapper<MatrixT, VectorT> wrapper_type;
wrapper_type wrapper(system_matrix, load_vector);
detail::pde_assembler_internal()(storage, transformed_weak_form, pde_system, domain, wrapper);
// pde_assembler_internal()(transformed_weak_form, pde_system, domain, system_matrix, load_vector);
}
void CholeskyDecomposition<T>::LTBackSub(const VectorT& b, VectorT& x) const
{
x.resize(L.n);
if(!LtBackSubstitute(L,b,x)) FatalError("CholeskyDecomposition: LtBackSubstitute failed!");
}
