HessenbergSchurInfo
ScaLAPACKHelper
( AbstractDistMatrix<F>& HPre,
AbstractDistMatrix<Complex<Base<F>>>& wPre,
AbstractDistMatrix<F>& ZPre,
const HessenbergSchurCtrl& ctrl )
{
EL_DEBUG_CSE
typedef Base<F> Real;
AssertScaLAPACKSupport();
HessenbergSchurInfo info;
ProxyCtrl proxyCtrl;
proxyCtrl.colConstrain = true;
proxyCtrl.rowConstrain = true;
proxyCtrl.blockHeight = ctrl.blockHeight;
proxyCtrl.blockWidth = ctrl.blockHeight;
proxyCtrl.colAlign = 0;
proxyCtrl.rowAlign = 0;
proxyCtrl.colCut = 0;
proxyCtrl.rowCut = 0;
DistMatrixReadWriteProxy<F,F,MC,MR,BLOCK> HProx( HPre, proxyCtrl );
auto& H = HProx.Get();
const Int n = H.Height();
DistMatrixReadWriteProxy<F,F,MC,MR,BLOCK> ZProx( ZPre, proxyCtrl );
auto& Z = ZProx.Get();
if( !ctrl.accumulateSchurVecs )
Identity( Z, n, n );
DistMatrixWriteProxy<Complex<Real>,Complex<Real>,STAR,STAR> wProx( wPre );
auto& w = wProx.Get();
#ifdef EL_HAVE_SCALAPACK
bool accumulateSchurVecs=true;
bool useAED = ( ctrl.alg == HESSENBERG_SCHUR_AED );
auto descH = FillDesc( H );
scalapack::HessenbergSchur
( n,
H.Buffer(), descH.data(),
w.Buffer(),
Z.Buffer(), descH.data(),
ctrl.fullTriangle,
accumulateSchurVecs,
useAED );
// TODO(poulson): Find a way to fill in info?
#endif
return info;
}
void ScaLAPACKHelper
( DistMatrix<F,MC,MR,BLOCK>& A,
DistMatrix<F,MR,STAR,BLOCK>& householderScalars )
{
EL_DEBUG_CSE
AssertScaLAPACKSupport();
#ifdef EL_HAVE_SCALAPACK
const Int m = A.Height();
const Int n = A.Width();
const Int minDim = Min(m,n);
householderScalars.AlignWith( A );
householderScalars.Resize( minDim, 1 );
auto descA = FillDesc( A );
scalapack::QR
( m, n, A.Buffer(), descA.data(), householderScalars.Buffer() );
#endif
}
void QR
( DistMatrix<F,MC,MR,BLOCK>& A,
DistMatrix<F,MR,STAR,BLOCK>& phase )
{
DEBUG_CSE
AssertScaLAPACKSupport();
#ifdef EL_HAVE_SCALAPACK
const Int m = A.Height();
const Int n = A.Width();
const Int minDim = Min(m,n);
phase.AlignWith( A );
phase.Resize( minDim, 1 );
const int bHandle = blacs::Handle( A );
const int context = blacs::GridInit( bHandle, A );
auto descA = FillDesc( A, context );
scalapack::QR( m, n, A.Buffer(), descA.data(), phase.Buffer() );
blacs::FreeGrid( context );
blacs::FreeHandle( bHandle );
#endif
}
SVDInfo ScaLAPACKHelper
( const AbstractDistMatrix<F>& APre,
AbstractDistMatrix<F>& UPre,
AbstractDistMatrix<Base<F>>& sPre,
AbstractDistMatrix<F>& V,
const SVDCtrl<Base<F>>& ctrl )
{
DEBUG_CSE
AssertScaLAPACKSupport();
SVDInfo info;
#ifdef EL_HAVE_SCALAPACK
typedef Base<F> Real;
DistMatrix<F,MC,MR,BLOCK> A( APre );
DistMatrixWriteProxy<Real,Real,STAR,STAR> sProx(sPre);
DistMatrixWriteProxy<F,F,MC,MR,BLOCK> UProx(UPre);
auto& s = sProx.Get();
auto& U = UProx.Get();
const int m = A.Height();
const int n = A.Width();
const int k = Min(m,n);
auto approach = ctrl.bidiagSVDCtrl.approach;
if( approach == THIN_SVD || approach == COMPACT_SVD )
{
Zeros( U, m, k );
DistMatrix<F,MC,MR,BLOCK> VH( A.Grid() );
Zeros( VH, k, n );
s.Resize( k, 1 );
auto descA = FillDesc( A );
auto descU = FillDesc( U );
auto descVH = FillDesc( VH );
scalapack::SVD
( m, n,
A.Buffer(), descA.data(),
s.Buffer(),
U.Buffer(), descU.data(),
VH.Buffer(), descVH.data() );
const bool compact = ( approach == COMPACT_SVD );
if( compact )
{
const Real twoNorm = ( k==0 ? Real(0) : s.Get(0,0) );
const Real thresh =
bidiag_svd::APosterioriThreshold
( m, n, twoNorm, ctrl.bidiagSVDCtrl );
Int rank = k;
for( Int j=0; j<k; ++j )
{
if( s.Get(j,0) <= thresh )
{
rank = j;
break;
}
}
s.Resize( rank, 1 );
U.Resize( m, rank );
VH.Resize( rank, n );
}
Adjoint( VH, V );
}
else
LogicError
("Only Thin and Compact singular value options currently supported");
#endif
return info;
}
