InfinityNorm( const DistMatrix<F,U,V>& A )
{
#ifndef RELEASE
CallStackEntry entry("InfinityNorm");
#endif
// Compute the partial row sums defined by our local matrix, A[U,V]
typedef BASE(F) R;
const Int localHeight = A.LocalHeight();
const Int localWidth = A.LocalWidth();
std::vector<R> myPartialRowSums( localHeight );
for( Int iLoc=0; iLoc<localHeight; ++iLoc )
{
myPartialRowSums[iLoc] = 0;
for( Int jLoc=0; jLoc<localWidth; ++jLoc )
myPartialRowSums[iLoc] += Abs(A.GetLocal(iLoc,jLoc));
}
// Sum our partial row sums to get the row sums over A[U,* ]
std::vector<R> myRowSums( localHeight );
mpi::Comm rowComm = ReduceRowComm<U,V>( A.Grid() );
mpi::AllReduce( &myPartialRowSums[0], &myRowSums[0], localHeight, rowComm );
// Find the maximum out of the row sums
R myMaxRowSum = 0;
for( Int iLoc=0; iLoc<localHeight; ++iLoc )
myMaxRowSum = std::max( myMaxRowSum, myRowSums[iLoc] );
// Find the global maximum row sum by searching over the U team
mpi::Comm colComm = ReduceColComm<U,V>( A.Grid() );
return mpi::AllReduce( myMaxRowSum, mpi::MAX, colComm );
}
inline typename Base<F>::type
internal::InfinityNorm( const DistMatrix<F,MC,MR>& A )
{
#ifndef RELEASE
PushCallStack("internal::InfinityNorm");
#endif
typedef typename Base<F>::type R;
// Compute the partial row sums defined by our local matrix, A[MC,MR]
std::vector<R> myPartialRowSums(A.LocalHeight());
for( int iLocal=0; iLocal<A.LocalHeight(); ++iLocal )
{
myPartialRowSums[iLocal] = 0;
for( int jLocal=0; jLocal<A.LocalWidth(); ++jLocal )
myPartialRowSums[iLocal] += Abs(A.GetLocalEntry(iLocal,jLocal));
}
// Sum our partial row sums to get the row sums over A[MC,* ]
std::vector<R> myRowSums(A.LocalHeight());
mpi::AllReduce
( &myPartialRowSums[0], &myRowSums[0], A.LocalHeight(), mpi::SUM,
A.Grid().RowComm() );
// Find the maximum out of the row sums
R myMaxRowSum = 0;
for( int iLocal=0; iLocal<A.LocalHeight(); ++iLocal )
myMaxRowSum = std::max( myMaxRowSum, myRowSums[iLocal] );
// Find the global maximum row sum by searching over the MC team
R maxRowSum = 0;
mpi::AllReduce( &myMaxRowSum, &maxRowSum, 1, mpi::MAX, A.Grid().ColComm() );
#ifndef RELEASE
PopCallStack();
#endif
return maxRowSum;
}
