DistMultiVec<T>
DistMultiVec<T>::operator()( const vector<Int>& I, const vector<Int>& J ) const
{
DEBUG_ONLY(CSE cse("DistMultiVec::operator()"))
DistMultiVec<T> ASub(this->Comm());
GetSubmatrix( *this, I, J, ASub );
return ASub;
}
void DruinskyToledo( ElementalMatrix<F>& A, Int k )
{
EL_DEBUG_CSE
const Int n = 2*k;
Zeros( A, n, n );
if( k == 0 )
return;
if( k == 1 )
{
Ones( A, n, n );
return;
}
typedef Base<F> Real;
const Real phi = Real(1) + 4*limits::Epsilon<Real>();
const Real alphaPhi = LDLPivotConstant<Real>(BUNCH_KAUFMAN_A)*phi;
vector<Real> d( k-2 );
Real sigma(1);
for( Int i=0; i<k-2; ++i )
{
d[i] = -alphaPhi/sigma;
sigma -= 1/d[i];
}
unique_ptr<ElementalMatrix<F>> ASub( A.Construct(A.Grid(),A.Root()) );
View( *ASub, A, IR(k-2,k), IR(0,k) );
Ones( *ASub, 2, k );
View( *ASub, A, IR(0,k), IR(k-2,k) );
Ones( *ASub, k, 2 );
View( *ASub, A, IR(0,k-2), IR(0,k-2) );
Diagonal( *ASub, d );
View( *ASub, A, IR(k,n), IR(0,k) );
Identity( *ASub, k, k );
View( *ASub, A, IR(k,n), IR(k,n) );
Identity( *ASub, k, k );
View( *ASub, A, IR(0,k), IR(k,n) );
Identity( *ASub, k, k );
}
static AValue TestC_ASub(AThread *t, AValue *frame)
{
return ASub(t, frame[0], frame[1]);
}
