// DPOSV uses Cholesky factorization A=U^T*U, A=L*L^T
// to compute the solution to a real system of linear
// equations A*X=B, where A is a square, (N,N) symmetric
// positive definite matrix and X and B are (N,NRHS).
//
// If the system is over or under-determined,
// (i.e. A is not square), then pass the problem
// to the Least-squares solver (DGELSS) below.
//---------------------------------------------------------
void umSOLVE_CH(const DMat& mat, const DMat& B, DMat& X)
//---------------------------------------------------------
{
if (!mat.ok()) {umWARNING("umSOLVE_CH()", "system is empty"); return;}
if (!mat.is_square()) {
umSOLVE_LS(mat, B, X); // return a least-squares solution.
return;
}
DMat A(mat); // Work with a copy of input array.
X = B; // initialize solution with rhs
int rows=A.num_rows(), LDA=A.num_rows(), cols=A.num_cols();
int LDB=X.num_rows(), NRHS=X.num_cols(), info=0;
assert(LDB >= rows); // enough space for solutions?
// Solve the system.
POSV('U', rows, NRHS, A.data(), LDA, X.data(), LDB, info);
if (info < 0) {
X = 0.0;
umERROR("umSOLVE_CH(A,B, X)",
"Error in input argument (%d)\nNo solution computed.", -info);
} else if (info > 0) {
X = 0.0;
umERROR("umSOLVE_CH(A,B, X)",
"\nINFO = %d. The leading minor of order %d of A"
"\nis not positive definite, so the factorization"
"\ncould not be completed. No solution computed.",
info, info);
}
}
// DGESV uses the LU factorization to compute solution
// to a real system of linear equations, A * X = B,
// where A is square (N,N) and X, B are (N,NRHS).
//
// If the system is over or under-determined,
// (i.e. A is not square), then pass the problem
// to the Least-squares solver (DGELSS) below.
//---------------------------------------------------------
void umSOLVE(const DMat& mat, const DMat& B, DMat& X)
//---------------------------------------------------------
{
if (!mat.ok()) {umWARNING("umSOLVE()", "system is empty"); return;}
if (!mat.is_square()) {
umSOLVE_LS(mat, B, X); // return a least-squares solution.
return;
}
DMat A(mat); // work with copy of input
X = B; // initialize result with RHS
int rows=A.num_rows(), LDA=A.num_rows(), cols=A.num_cols();
int LDB=B.num_rows(), NRHS=B.num_cols(), info=0;
if (rows<1) {umWARNING("umSOLVE()", "system is empty"); return;}
IVec ipiv(rows);
// Solve the system.
GESV(rows, NRHS, A.data(), LDA, ipiv.data(), X.data(), LDB, info);
if (info < 0) {
X = 0.0;
umERROR("umSOLVE(A,B, X)",
"Error in input argument (%d)\nNo solution computed.", -info);
} else if (info > 0) {
X = 0.0;
umERROR("umSOLVE(A,B, X)",
"\nINFO = %d. U(%d,%d) was exactly zero."
"\nThe factorization has been completed, but the factor U is "
"\nexactly singular, so the solution could not be computed.",
info, info, info);
}
}
//---------------------------------------------------------
void umAxB(const DMat& A, const DMat& B, DMat& C)
//---------------------------------------------------------
{
//-------------------------
// C = A * B
//-------------------------
// A = op(A) is (M,K)
// B = op(B) is (K,N)
// C is (M,N)
//-------------------------
int M=A.num_rows(), K=A.num_cols(), N=B.num_cols();
int LDA=M, LDB=K, LDC=M;
double one=1.0, zero=0.0;
if (B.num_rows() != K) { umERROR("umAxB(A,B,C)", "wrong dimensions"); }
C.resize(M,N);
GEMM ('N','N',M,N,K, one,A.data(),LDA,
B.data(),LDB,
zero,C.data(),LDC);
}
//---------------------------------------------------------
bool chol_solve(const DMat& ch, const DMat& B, DMat& X)
//---------------------------------------------------------
{
// Solve a set of linear systems using Cholesky-factored
// symmetric positive-definite matrix, A = U^T U.
if (FACT_CHOL != ch.get_factmode()) {umERROR("chol_solve(ch,B,X)", "matrix is not factored.");}
int M =ch.num_rows(), lda=ch.num_rows();
int ldb=B.num_rows(), nrhs=B.num_cols(); assert(ldb == M);
char uplo = 'U'; int info=0;
double* ch_data = const_cast<double*>(ch.data());
X = B; // overwrite X with RHS's, then solutions
POTRS (uplo, M, nrhs, ch_data, lda, X.data(), ldb, info);
if (info) { umERROR("chol_solve(ch,B,X)", "dpotrs reports: info = %d", info); }
return true;
}
// tex "table" output
//---------------------------------------------------------
void textable
(
string& capt,
FILE* fid,
string* titles,
DMat& entries,
string* form
)
//---------------------------------------------------------
{
int Nrows=entries.num_rows(), Ncols=entries.num_cols(), n=0,m=0;
fprintf(fid, "\\begin{table} \n");
fprintf(fid, "\\caption{%s} \n", capt.c_str());
fprintf(fid, "\\begin{center} \n");
fprintf(fid, "\\begin{tabular}{|");
for (n=1; n<=Ncols; ++n) {
fprintf(fid, "c|");
if (2==n) {
fprintf(fid, "|");
}
}
fprintf(fid, "} \\hline \n ");
for (n=1; n<=(Ncols-1); ++n) {
fprintf(fid, "%s & ", titles[n].c_str());
}
fprintf(fid, " %s \\\\ \\hline \n ", titles[Ncols].c_str());
for (m=1; m<=Nrows; ++m) {
for (n=1; n<=(Ncols-1); ++n) {
fprintf(fid, form[n].c_str(), entries(m,n)); fprintf(fid, " & ");
}
if (m<Nrows) {
fprintf(fid, form[Ncols].c_str(), entries(m,Ncols)); fprintf(fid, " \\\\ \n ");
} else {
fprintf(fid, form[Ncols].c_str(), entries(m,Ncols)); fprintf(fid, " \\\\ \\hline \n ");
}
}
fprintf(fid, "\\end{tabular} \n");
fprintf(fid, "\\end{center} \n");
fprintf(fid, "\\end{table} \n");
}
// DGELSS computes minimum norm solution to a real linear
// least squares problem: Minimize 2-norm(| b - A*x |).
// using the singular value decomposition (SVD) of A.
// A is an M-by-N matrix which may be rank-deficient.
//---------------------------------------------------------
void umSOLVE_LS(const DMat& mat, const DMat& B, DMat& X)
//---------------------------------------------------------
{
if (!mat.ok()) {umWARNING("umSOLVE_LS()", "system is empty"); return;}
DMat A(mat); // work with copy of input.
int rows=A.num_rows(), cols=A.num_cols(), mmn=A.min_mn();
int LDB=A.max_mn(), NRHS=B.num_cols();
if (rows!=B.num_rows()) {umERROR("umSOLVE_LS(A,B)", "Inconsistant matrix sizes.");}
DVec s(mmn); // allocate array for singular values
// X must be big enough to store various results.
// Resize X so that its leading dimension = max(M,N),
// then load the set of right hand sides.
X.resize(LDB,NRHS, true, 0.0);
for (int j=1; j<=NRHS; ++j) // loop across colums
for (int i=1; i<=rows; ++i) // loop down rows
X(i,j) = B(i,j);
// RCOND is used to determine the effective rank of A.
// Singular values S(i) <= RCOND*S(1) are treated as zero.
// If RCOND < 0, machine precision is used instead.
//double rcond = 1.0 / 1.0e16;
double rcond = -1.0;
// NBN: ACML does not use the work vector.
int mnLo=A.min_mn(), mnHi=A.max_mn(), rank=1, info=1;
int lwork = 10*mnLo + std::max(2*mnLo, std::max(mnHi, NRHS));
DVec work(lwork);
// Solve the system
GELSS (rows, cols, NRHS, A.data(), rows, X.data(), LDB, s.data(), rcond, rank, work.data(), lwork, info);
//---------------------------------------------
// Report:
//---------------------------------------------
if (info == 0) {
umLOG(1, "umSOLVE_LS reports successful LS-solution."
"\nRCOND = %0.6e, "
"\nOptimal length of work array was %d\n", rcond, lwork);
}
else
{
if (info < 0) {
X = 0.0;
umERROR("umSOLVE_LS(DMat&, DMat&)",
"Error in input argument (%d)\nNo solution or error bounds computed.", -info);
} else if (info > 0) {
X = 0.0;
umERROR("umSOLVE_LS(DMat&, DMat&)",
"\nThe algorithm for computing the SVD failed to converge.\n"
"\n%d off-diagonal elements of an intermediate "
"\nbidiagonal form did not converge to zero.\n "
"\nRCOND = %0.6e, "
"\nOptimal length of work array was %d.\n", info, rcond, lwork);
}
}
}
//---------------------------------------------------------
void NDG2D::OutputSampleXYZ
(
int sample_N,
DMat &newX,
DMat &newY,
DMat &newZ, // e.g. triangles on a sphere
const DMat &FData, // old field data
DMat &newFData, // new field data
int zfield // if>0, use as z-elevation
)
//---------------------------------------------------------
{
DVec newR, newS, newT;
DMat newVDM;
int newNpts = 0;
// Triangles
OutputSampleNodes2D(sample_N, newR, newS);
newNpts = newR.size();
newVDM = Vandermonde2D(this->N, newR, newS);
const DMat& oldV = this->V;
DMat oldtonew(newNpts, this->Np, "OldToNew");
oldtonew = trans(trans(oldV) | trans(newVDM));
//-----------------------------------
// interpolate the field data
//-----------------------------------
int Nfields = FData.num_cols();
newFData.resize(newNpts*this->K, Nfields);
//DVec scales(Nfields);
// For each field, use tOldF to wrap field i.
// Use tNewF to load the interpolated field
// directly into column i of the output array.
DMat tOldF, tNewF;
for (int i=1; i<=Nfields; ++i) {
tOldF.borrow(this->Np, this->K, (double*) FData.pCol(i));
tNewF.borrow(newNpts, this->K, (double*)newFData.pCol(i));
tNewF = oldtonew * tOldF;
//scales(i) = tNewF.max_col_val_abs(i);
}
//-----------------------------------
// interpolate the vertices
//-----------------------------------
newX = oldtonew * this->x;
newY = oldtonew * this->y;
if (this->bCoord3D) {
newZ = oldtonew * this->z;
}
else
{
if (zfield>=1 && zfield<=Nfields) {
// use field data for z-height
newZ.load(newNpts, K, newFData.pCol(Nfields));
} else {
// set z-data to 0.0
newZ.resize(newNpts, K, true, 0.0);
}
}
}
//---------------------------------------------------------
void NDG2D::OutputVTK(const DMat& FData, int order, int zfield)
//---------------------------------------------------------
{
static int count = 0;
string output_dir = ".";
// The caller loads each field of interest into FData,
// storing (Np*K) scalars per column.
//
// For high (or low) resolution output, the user can
// specify an arbitrary order of interpolation for
// exporting the fields. Thus while a simulation may
// use N=3, we can export the solution fields with
// high-order, regularized elements (e.g. with N=12).
string buf = umOFORM("%s/sim_N%02d_%04d.vtk", output_dir.c_str(), order, ++count);
FILE *fp = fopen(buf.c_str(), "w");
if (!fp) {
umLOG(1, "Could no open %s for output!\n", buf.c_str());
return;
}
// Set flags and totals
int Output_N = std::max(2, order);
int Ncells=0, Npts=0;
Ncells = OutputSampleNelmt2D(Output_N);
Npts = OutputSampleNpts2D (Output_N);
// set totals for Vtk output
int vtkTotalPoints = this->K * Npts;
int vtkTotalCells = this->K * Ncells;
int vtkTotalConns = (this->EToV.num_cols()+1) * this->K * Ncells;
//-------------------------------------
// 1. Write the VTK header details
//-------------------------------------
fprintf(fp, "# vtk DataFile Version 2");
fprintf(fp, "\nNuDG++ 2D simulation");
fprintf(fp, "\nASCII");
fprintf(fp, "\nDATASET UNSTRUCTURED_GRID\n");
fprintf(fp, "\nPOINTS %d double", vtkTotalPoints);
int newNpts=0;
//-------------------------------------
// 2. Write the vertex data
//-------------------------------------
DMat newX, newY, newZ, newFData;
// Build new {X,Y,Z} vertices that regularize the
// elements, then interpolate solution fields onto
// this new set of elements:
OutputSampleXYZ(Output_N, newX, newY, newZ, FData, newFData, zfield);
//double maxF1 = newFData.max_col_val_abs(1), scaleF=1.0;
//if (maxF1 != 0.0) { scaleF = 1.0/maxF1; }
newNpts = newX.num_rows();
if (zfield>0)
{
// write 2D vertex data, with z-elevation
for (int k=1; k<=this->K; ++k) {
for (int n=1; n<=newNpts; ++n) {
// use exponential format to allow for
// arbitrary (astro, nano) magnitudes:
fprintf(fp, "\n%20.12e %20.12e %20.12e",
newX(n, k), newY(n, k), newZ(n,k)); //*scaleF);
}
}
} else {
// write 2D vertex data to file
for (int k=1; k<=this->K; ++k) {
for (int n=1; n<=newNpts; ++n) {
// use exponential format to allow for
// arbitrary (astro, nano) magnitudes:
fprintf(fp, "\n%20.12e %20.12e 0.0",
newX(n, k), newY(n, k));
}
}
}
//-------------------------------------
// 3. Write the element connectivity
//-------------------------------------
IMat newELMT;
// Number of indices required to define connectivity
fprintf(fp, "\n\nCELLS %d %d", vtkTotalCells, vtkTotalConns);
// build regularized tri elements at selected order
OutputSampleELMT2D(Output_N, newELMT);
newNpts = OutputSampleNpts2D(Output_N);
int newNTri = newELMT.num_rows();
int newNVert = newELMT.num_cols();
// write element connectivity to file
for (int k=0; k<this->K; ++k) {
int nodesk = k*newNpts;
for (int n=1; n<=newNTri; ++n) {
fprintf(fp, "\n%d", newNVert);
for (int i=1; i<=newNVert; ++i) {
fprintf(fp, " %5d", nodesk+newELMT(n, i));
}
}
}
//-------------------------------------
// 4. Write the cell types
//-------------------------------------
// For each element (cell) write a single integer
// identifying the cell type. The integer should
// correspond to the enumeration in the vtk file:
// /VTK/Filtering/vtkCellType.h
fprintf(fp, "\n\nCELL_TYPES %d", vtkTotalCells);
for (int k=0; k<this->K; ++k) {
fprintf(fp, "\n");
for (int i=1; i<=Ncells; ++i) {
fprintf(fp, "5 "); // 5:VTK_TRIANGLE
if (! (i%10))
fprintf(fp, "\n");
}
}
//-------------------------------------
// 5. Write the scalar "vtkPointData"
//-------------------------------------
fprintf(fp, "\n\nPOINT_DATA %d", vtkTotalPoints);
// For each field, write POINT DATA for each point
// in the vtkUnstructuredGrid.
int Nfields = FData.num_cols();
for (int fld=1; fld<=Nfields; ++fld)
{
fprintf(fp, "\nSCALARS field%d double 1", fld);
fprintf(fp, "\nLOOKUP_TABLE default");
// Write the scalar data, using exponential format
// to allow for arbitrary (astro, nano) magnitudes:
for (int n=1; n<=newFData.num_rows(); ++n) {
fprintf(fp, "\n%20.12e ", newFData(n, fld));
}
}
// add final newline to output
fprintf(fp, "\n");
fclose(fp);
}