int BandMatrix::solve(int n, doublereal* b) {
int info = 0;
if (!m_factored) info = factor();
if (info == 0)
ct_dgbtrs(ctlapack::NoTranspose, columns(), nSubDiagonals(),
nSuperDiagonals(), 1, DATA_PTR(ludata), ldim(),
DATA_PTR(ipiv()), b, columns(), info);
// error handling
if (info != 0) {
ofstream fout("bandmatrix.csv");
fout << *this << endl;
fout.close();
}
return info;
}
int BandMatrix::factor()
{
int info=0;
ludata = data;
ct_dgbtrf(nRows(), nColumns(), nSubDiagonals(), nSuperDiagonals(),
ludata.data(), ldim(), ipiv().data(), info);
// if info = 0, LU decomp succeeded.
if (info == 0) {
m_factored = true;
} else {
m_factored = false;
ofstream fout("bandmatrix.csv");
fout << *this << endl;
}
return info;
}
/**
* Perform an LU decomposition. LAPACK routine DGBTRF is used.
* The factorization is saved in ludata.
*/
int BandMatrix::factor() {
int info=0;
copy(data.begin(), data.end(), ludata.begin());
ct_dgbtrf(rows(), columns(), nSubDiagonals(), nSuperDiagonals(),
DATA_PTR(ludata), ldim(), DATA_PTR(ipiv()), info);
// if info = 0, LU decomp succeeded.
if (info == 0) {
m_factored = true;
}
else {
m_factored = false;
ofstream fout("bandmatrix.csv");
fout << *this << endl;
fout.close();
}
return info;
}
int BandMatrix::solve(doublereal* b, size_t nrhs, size_t ldb)
{
int info = 0;
if (!m_factored) {
info = factor();
}
if (ldb == 0) {
ldb = nColumns();
}
if (info == 0) {
ct_dgbtrs(ctlapack::NoTranspose, nColumns(), nSubDiagonals(),
nSuperDiagonals(), nrhs, ludata.data(), ldim(),
ipiv().data(), b, ldb, info);
}
// error handling
if (info != 0) {
ofstream fout("bandmatrix.csv");
fout << *this << endl;
}
return info;
}
