void EntrywiseMap
( const ElementalMatrix<S>& A,
ElementalMatrix<T>& B,
function<T(S)> func )
{
if( A.DistData().colDist == B.DistData().colDist &&
A.DistData().rowDist == B.DistData().rowDist )
{
B.AlignWith( A.DistData() );
B.Resize( A.Height(), A.Width() );
EntrywiseMap( A.LockedMatrix(), B.Matrix(), func );
}
else
{
B.Resize( A.Height(), A.Width() );
#define GUARD(CDIST,RDIST) \
B.DistData().colDist == CDIST && B.DistData().rowDist == RDIST
#define PAYLOAD(CDIST,RDIST) \
DistMatrix<S,CDIST,RDIST> AProx(B.Grid()); \
AProx.AlignWith( B.DistData() ); \
Copy( A, AProx ); \
EntrywiseMap( AProx.Matrix(), B.Matrix(), func );
#include <El/macros/GuardAndPayload.h>
#undef GUARD
#undef PAYLOAD
}
}
void PartialColScatter
( T alpha,
const ElementalMatrix<T>& A,
ElementalMatrix<T>& B )
{
DEBUG_ONLY(CSE cse("axpy_contract::PartialColScatter"))
AssertSameGrids( A, B );
if( A.Height() != B.Height() || A.Width() != B.Width() )
LogicError("A and B must be the same size");
#ifdef EL_CACHE_WARNINGS
if( A.Width() != 1 && A.Grid().Rank() == 0 )
{
cerr <<
"axpy_contract::PartialColScatterUpdate potentially causes a large "
"amount of cache-thrashing. If possible, avoid it by forming the "
"(conjugate-)transpose of the [UGath,* ] matrix instead."
<< endl;
}
#endif
if( B.ColAlign() % A.ColStride() == A.ColAlign() )
{
const Int colStride = B.ColStride();
const Int colStridePart = B.PartialColStride();
const Int colStrideUnion = B.PartialUnionColStride();
const Int colRankPart = B.PartialColRank();
const Int colAlign = B.ColAlign();
const Int height = B.Height();
const Int width = B.Width();
const Int localHeight = B.LocalHeight();
const Int maxLocalHeight = MaxLength( height, colStride );
const Int recvSize = mpi::Pad( maxLocalHeight*width );
const Int sendSize = colStrideUnion*recvSize;
//vector<T> buffer( sendSize );
vector<T> buffer;
buffer.reserve( sendSize );
// Pack
copy::util::PartialColStridedPack
( height, width,
colAlign, colStride,
colStrideUnion, colStridePart, colRankPart,
A.ColShift(),
A.LockedBuffer(), A.LDim(),
buffer.data(), recvSize );
// Communicate
mpi::ReduceScatter( buffer.data(), recvSize, B.PartialUnionColComm() );
// Unpack our received data
axpy::util::InterleaveMatrixUpdate
( alpha, localHeight, width,
buffer.data(), 1, localHeight,
B.Buffer(), 1, B.LDim() );
}
else
LogicError("Unaligned PartialColScatter not implemented");
}
void PartialRowScatter
( T alpha,
const ElementalMatrix<T>& A,
ElementalMatrix<T>& B )
{
DEBUG_ONLY(CSE cse("axpy_contract::PartialRowScatter"))
AssertSameGrids( A, B );
if( A.Height() != B.Height() || A.Width() != B.Width() )
LogicError("Matrix sizes did not match");
if( !B.Participating() )
return;
if( B.RowAlign() % A.RowStride() == A.RowAlign() )
{
const Int rowStride = B.RowStride();
const Int rowStridePart = B.PartialRowStride();
const Int rowStrideUnion = B.PartialUnionRowStride();
const Int rowRankPart = B.PartialRowRank();
const Int height = B.Height();
const Int width = B.Width();
const Int maxLocalWidth = MaxLength( width, rowStride );
const Int recvSize = mpi::Pad( height*maxLocalWidth );
const Int sendSize = rowStrideUnion*recvSize;
//vector<T> buffer( sendSize );
vector<T> buffer;
buffer.reserve( sendSize );
// Pack
copy::util::PartialRowStridedPack
( height, width,
B.RowAlign(), rowStride,
rowStrideUnion, rowStridePart, rowRankPart,
A.RowShift(),
A.LockedBuffer(), A.LDim(),
buffer.data(), recvSize );
// Communicate
mpi::ReduceScatter( buffer.data(), recvSize, B.PartialUnionRowComm() );
// Unpack our received data
axpy::util::InterleaveMatrixUpdate
( alpha, height, B.LocalWidth(),
buffer.data(), 1, height,
B.Buffer(), 1, B.LDim() );
}
else
LogicError("Unaligned PartialRowScatter not implemented");
}
Base<F> Coherence( const ElementalMatrix<F>& A )
{
DEBUG_ONLY(CSE cse("Coherence"))
DistMatrix<F> B( A );
DistMatrix<Base<F>,MR,STAR> norms(B.Grid());
ColumnTwoNorms( B, norms );
DiagonalSolve( RIGHT, NORMAL, norms, B, true );
DistMatrix<F> C(B.Grid());
Identity( C, A.Width(), A.Width() );
Herk( UPPER, ADJOINT, Base<F>(-1), B, Base<F>(1), C );
return HermitianMaxNorm( UPPER, C );
}
void Contract
( const ElementalMatrix<T>& A,
ElementalMatrix<T>& B )
{
DEBUG_ONLY(CSE cse("Contract"))
AssertSameGrids( A, B );
const Dist U = B.ColDist();
const Dist V = B.RowDist();
// TODO: Shorten this implementation?
if( A.ColDist() == U && A.RowDist() == V )
{
Copy( A, B );
}
else if( A.ColDist() == U && A.RowDist() == Partial(V) )
{
B.AlignAndResize
( A.ColAlign(), A.RowAlign(), A.Height(), A.Width(), false, false );
Zeros( B.Matrix(), B.LocalHeight(), B.LocalWidth() );
AxpyContract( T(1), A, B );
}
else if( A.ColDist() == Partial(U) && A.RowDist() == V )
{
B.AlignAndResize
( A.ColAlign(), A.RowAlign(), A.Height(), A.Width(), false, false );
Zeros( B.Matrix(), B.LocalHeight(), B.LocalWidth() );
AxpyContract( T(1), A, B );
}
else if( A.ColDist() == U && A.RowDist() == Collect(V) )
{
B.AlignColsAndResize
( A.ColAlign(), A.Height(), A.Width(), false, false );
Zeros( B.Matrix(), B.LocalHeight(), B.LocalWidth() );
AxpyContract( T(1), A, B );
}
else if( A.ColDist() == Collect(U) && A.RowDist() == V )
{
B.AlignRowsAndResize
( A.RowAlign(), A.Height(), A.Width(), false, false );
Zeros( B.Matrix(), B.LocalHeight(), B.LocalWidth() );
AxpyContract( T(1), A, B );
}
else if( A.ColDist() == Collect(U) && A.RowDist() == Collect(V) )
{
Zeros( B, A.Height(), A.Width() );
AxpyContract( T(1), A, B );
}
else
LogicError("Incompatible distributions");
}
void Scatter
( T alpha,
const ElementalMatrix<T>& A,
ElementalMatrix<T>& B )
{
DEBUG_ONLY(CSE cse("axpy_contract::Scatter"))
AssertSameGrids( A, B );
if( A.Height() != B.Height() || A.Width() != B.Width() )
LogicError("Sizes of A and B must match");
if( !B.Participating() )
return;
const Int colStride = B.ColStride();
const Int rowStride = B.RowStride();
const Int colAlign = B.ColAlign();
const Int rowAlign = B.RowAlign();
const Int height = B.Height();
const Int width = B.Width();
const Int localHeight = B.LocalHeight();
const Int localWidth = B.LocalWidth();
const Int maxLocalHeight = MaxLength(height,colStride);
const Int maxLocalWidth = MaxLength(width,rowStride);
const Int recvSize = mpi::Pad( maxLocalHeight*maxLocalWidth );
const Int sendSize = colStride*rowStride*recvSize;
//vector<T> buffer( sendSize );
vector<T> buffer;
buffer.reserve( sendSize );
// Pack
copy::util::StridedPack
( height, width,
colAlign, colStride,
rowAlign, rowStride,
A.LockedBuffer(), A.LDim(),
buffer.data(), recvSize );
// Communicate
mpi::ReduceScatter( buffer.data(), recvSize, B.DistComm() );
// Unpack our received data
axpy::util::InterleaveMatrixUpdate
( alpha, localHeight, localWidth,
buffer.data(), 1, localHeight,
B.Buffer(), 1, B.LDim() );
}
void TransposeContract
( const ElementalMatrix<T>& A,
ElementalMatrix<T>& B, bool conjugate )
{
EL_DEBUG_CSE
const Dist U = B.ColDist();
const Dist V = B.RowDist();
if( A.ColDist() == V && A.RowDist() == Partial(U) )
{
Transpose( A, B, conjugate );
}
else
{
unique_ptr<ElementalMatrix<T>>
ASumFilt( B.ConstructTranspose(B.Grid(),B.Root()) );
if( B.ColConstrained() )
ASumFilt->AlignRowsWith( B, true );
if( B.RowConstrained() )
ASumFilt->AlignColsWith( B, true );
Contract( A, *ASumFilt );
if( !B.ColConstrained() )
B.AlignColsWith( *ASumFilt, false );
if( !B.RowConstrained() )
B.AlignRowsWith( *ASumFilt, false );
// We should have ensured that the alignments match
B.Resize( A.Width(), A.Height() );
Transpose( ASumFilt->LockedMatrix(), B.Matrix(), conjugate );
}
}
void AugmentedKKT
( const ElementalMatrix<Real>& A,
const ElementalMatrix<Real>& x,
const ElementalMatrix<Real>& z,
ElementalMatrix<Real>& JPre,
bool onlyLower )
{
EL_DEBUG_CSE
const Int m = A.Height();
const Int n = A.Width();
DistMatrixWriteProxy<Real,Real,MC,MR> JProx( JPre );
auto& J = JProx.Get();
Zeros( J, m+n, m+n );
const IR xInd(0,n), yInd(n,n+m);
auto Jxx = J(xInd,xInd); auto Jxy = J(xInd,yInd);
auto Jyx = J(yInd,xInd); auto Jyy = J(yInd,yInd);
DistMatrix<Real,MC,STAR> d( z );
DiagonalSolve( LEFT, NORMAL, x, d );
Diagonal( Jxx, d );
Jyx = A;
if( !onlyLower )
Transpose( A, Jxy );
}
void TestCorrectness
( bool print,
const ElementalMatrix<Complex<Real>>& A,
const ElementalMatrix<Complex<Real>>& w,
const ElementalMatrix<Complex<Real>>& V )
{
const Int n = A.Height();
const Real eps = limits::Epsilon<Real>();
const Real oneNormA = OneNorm( A );
// Find the residual R = AV-VW
DistMatrix<Complex<Real>> R( V.Height(), V.Width(), A.Grid() );
Gemm
( NORMAL, NORMAL,
Complex<Real>(1), A, V,
Complex<Real>(0), R);
DistMatrix<Complex<Real>> VW( V );
DiagonalScale( RIGHT, NORMAL, w, VW );
R -= VW;
const Real infError = InfinityNorm( R );
const Real relError = infError / (eps*n*oneNormA);
OutputFromRoot
(A.Grid().Comm(),"|| A V - V W ||_oo / (eps n || A ||_1) = ",relError);
// TODO: A more refined failure condition
if( relError > Real(100) )
LogicError("Relative error was unacceptably large");
}
void MaxEig
( const ElementalMatrix<Real>& xPre,
ElementalMatrix<Real>& maxEigsPre,
const ElementalMatrix<Int>& orders,
const ElementalMatrix<Int>& firstIndsPre,
Int cutoff )
{
DEBUG_ONLY(CSE cse("soc::MaxEig"))
AssertSameGrids( xPre, maxEigsPre, orders, firstIndsPre );
ElementalProxyCtrl ctrl;
ctrl.colConstrain = true;
ctrl.colAlign = 0;
DistMatrixReadProxy<Real,Real,VC,STAR>
xProx( xPre, ctrl );
DistMatrixWriteProxy<Real,Real,VC,STAR>
maxEigsProx( maxEigsPre, ctrl );
DistMatrixReadProxy<Int,Int,VC,STAR>
firstIndsProx( firstIndsPre, ctrl );
auto& x = xProx.GetLocked();
auto& maxEigs = maxEigsProx.Get();
auto& firstInds = firstIndsProx.GetLocked();
const Int height = x.Height();
const Int localHeight = x.LocalHeight();
DEBUG_ONLY(
if( x.Width() != 1 || orders.Width() != 1 || firstInds.Width() != 1 )
LogicError("x, orders, and firstInds should be column vectors");
if( orders.Height() != height || firstInds.Height() != height )
LogicError("orders and firstInds should be of the same height as x");
)
void ExplicitTriang( ElementalMatrix<F>& A )
{
DEBUG_ONLY(CSE cse("rq::ExplicitTriang"))
DistMatrix<F,MD,STAR> t(A.Grid());
DistMatrix<Base<F>,MD,STAR> d(A.Grid());
Householder( A, t, d );
MakeTrapezoidal( UPPER, A, A.Width()-A.Height() );
}
void IPM
( const ElementalMatrix<Real>& A,
const ElementalMatrix<Real>& b,
Real lambda,
ElementalMatrix<Real>& x,
const qp::affine::Ctrl<Real>& ctrl )
{
DEBUG_CSE
const Int m = A.Height();
const Int n = A.Width();
const Grid& g = A.Grid();
const Range<Int> uInd(0,n), vInd(n,2*n), rInd(2*n,2*n+m);
DistMatrix<Real> Q(g), c(g), AHat(g), G(g), h(g);
// Q := | 0 0 0 |
// | 0 0 0 |
// | 0 0 I |
// ==============
Zeros( Q, 2*n+m, 2*n+m );
auto Qrr = Q( rInd, rInd );
FillDiagonal( Qrr, Real(1) );
// c := lambda*[1;1;0]
// ===================
Zeros( c, 2*n+m, 1 );
auto cuv = c( IR(0,2*n), ALL );
Fill( cuv, lambda );
// \hat A := [A, -A, I]
// ====================
Zeros( AHat, m, 2*n+m );
auto AHatu = AHat( IR(0,m), uInd );
auto AHatv = AHat( IR(0,m), vInd );
auto AHatr = AHat( IR(0,m), rInd );
AHatu = A;
AHatv -= A;
FillDiagonal( AHatr, Real(1) );
// G := | -I 0 0 |
// | 0 -I 0 |
// ================
Zeros( G, 2*n, 2*n+m );
FillDiagonal( G, Real(-1) );
// h := 0
// ======
Zeros( h, 2*n, 1 );
// Solve the affine QP
// ===================
DistMatrix<Real> xHat(g), y(g), z(g), s(g);
QP( Q, AHat, G, b, c, h, xHat, y, z, s, ctrl );
// x := u - v
// ==========
x = xHat( uInd, ALL );
x -= xHat( vInd, ALL );
}
void ExplicitTriang( ElementalMatrix<F>& A )
{
DEBUG_CSE
const Grid& g = A.Grid();
DistMatrix<F,MD,STAR> householderScalars(g);
DistMatrix<Base<F>,MD,STAR> signature(g);
LQ( A, householderScalars, signature );
const Int m = A.Height();
const Int n = A.Width();
const Int minDim = Min(m,n);
A.Resize( m, minDim );
MakeTrapezoidal( LOWER, A );
}
void ExplicitTriang( ElementalMatrix<F>& A, const QRCtrl<Base<F>>& ctrl )
{
DEBUG_CSE
DistMatrix<F,MD,STAR> householderScalars(A.Grid());
DistMatrix<Base<F>,MD,STAR> signature(A.Grid());
if( ctrl.colPiv )
{
DistPermutation Omega(A.Grid());
BusingerGolub( A, householderScalars, signature, Omega, ctrl );
}
else
Householder( A, householderScalars, signature );
A.Resize( householderScalars.Height(), A.Width() );
MakeTrapezoidal( UPPER, A );
}
void ExplicitTriang( ElementalMatrix<F>& A, const QRCtrl<Base<F>>& ctrl )
{
DEBUG_ONLY(CSE cse("qr::ExplicitTriang"))
DistMatrix<F,MD,STAR> t(A.Grid());
DistMatrix<Base<F>,MD,STAR> d(A.Grid());
if( ctrl.colPiv )
{
DistPermutation Omega(A.Grid());
BusingerGolub( A, t, d, Omega, ctrl );
}
else
Householder( A, t, d );
A.Resize( t.Height(), A.Width() );
MakeTrapezoidal( UPPER, A );
}
void MakeExtendedKahan
( ElementalMatrix<F>& A, Base<F> phi, Base<F> mu )
{
EL_DEBUG_CSE
typedef Base<F> Real;
if( A.Height() != A.Width() )
LogicError("Extended Kahan matrices must be square");
const Int n = A.Height();
if( n % 3 != 0 )
LogicError("Dimension must be an integer multiple of 3");
const Int l = n / 3;
if( !l || (l & (l-1)) )
LogicError("n/3 is not a power of two");
Int k=0;
while( Int(1u<<k) < l )
++k;
if( phi <= Real(0) || phi >= Real(1) )
LogicError("phi must be in (0,1)");
if( mu <= Real(0) || mu >= Real(1) )
LogicError("mu must be in (0,1)");
// Start by setting A to the identity, and then modify the necessary
// l x l blocks of its 3 x 3 partitioning.
MakeIdentity( A );
unique_ptr<ElementalMatrix<F>> ABlock( A.Construct(A.Grid(),A.Root()) );
View( *ABlock, A, IR(2*l,3*l), IR(2*l,3*l) );
*ABlock *= mu;
View( *ABlock, A, IR(0,l), IR(l,2*l) );
Walsh( *ABlock, k );
*ABlock *= -phi;
View( *ABlock, A, IR(l,2*l), IR(2*l,3*l) );
Walsh( *ABlock, k );
*ABlock *= phi;
// Now scale A by S
const Real zeta = Sqrt(Real(1)-phi*phi);
auto& ALoc = A.Matrix();
for( Int iLoc=0; iLoc<A.LocalHeight(); ++iLoc )
{
const Int i = A.GlobalRow(iLoc);
const Real gamma = Pow(zeta,Real(i));
for( Int jLoc=0; jLoc<A.LocalWidth(); ++jLoc )
ALoc(iLoc,jLoc) *= gamma;
}
}
void KKT
( const ElementalMatrix<Real>& A,
const ElementalMatrix<Real>& x,
const ElementalMatrix<Real>& z,
ElementalMatrix<Real>& JPre, bool onlyLower )
{
EL_DEBUG_CSE
const Int m = A.Height();
const Int n = A.Width();
DistMatrixWriteProxy<Real,Real,MC,MR> JProx( JPre );
auto& J = JProx.Get();
Zeros( J, 2*n+m, 2*n+m );
const IR xInd(0,n), yInd(n,n+m), zInd(n+m,2*n+m);
auto Jxx = J(xInd,xInd); auto Jxy = J(xInd,yInd); auto Jxz = J(xInd,zInd);
auto Jyx = J(yInd,xInd); auto Jyy = J(yInd,yInd); auto Jyz = J(yInd,zInd);
auto Jzx = J(zInd,xInd); auto Jzy = J(zInd,yInd); auto Jzz = J(zInd,zInd);
// Jyx := A
// ========
Jyx = A;
// Jzx := -I
// =========
Identity( Jzx, n, n );
Jzx *= -1;
// Jzz := - z <> x
// ===============
DistMatrix<Real,MC,STAR> t(x);
DiagonalSolve( LEFT, NORMAL, z, t );
t *= -1;
Diagonal( Jzz, t );
if( !onlyLower )
{
// Jxy := A^T
// ==========
Transpose( A, Jxy );
// Jxz := -I
// =========
Identity( Jxz, n, n );
Jxz *= -1;
}
}
void
Householder
( ElementalMatrix<F>& APre,
ElementalMatrix<F>& phasePre,
ElementalMatrix<Base<F>>& signaturePre )
{
DEBUG_CSE
DEBUG_ONLY(AssertSameGrids( APre, phasePre, signaturePre ))
const Int m = APre.Height();
const Int n = APre.Width();
const Int minDim = Min(m,n);
const Int iOff = m-minDim;
const Int jOff = n-minDim;
DistMatrixReadWriteProxy<F,F,MC,MR> AProx( APre );
DistMatrixWriteProxy<F,F,MD,STAR> phaseProx( phasePre );
DistMatrixWriteProxy<Base<F>,Base<F>,MD,STAR> signatureProx( signaturePre );
auto& A = AProx.Get();
auto& phase = phaseProx.Get();
auto& signature = signatureProx.Get();
phase.Resize( minDim, 1 );
signature.Resize( minDim, 1 );
const Int bsize = Blocksize();
const Int kLast = LastOffset( minDim, bsize );
for( Int k=kLast; k>=0; k-=bsize )
{
const Int nb = Min(bsize,minDim-k);
const Int ki = k + iOff;
const Int kj = k + jOff;
const Range<Int> ind0Vert( 0, ki ),
ind1( k, k+nb ),
ind1Vert( ki, ki+nb ),
indL( 0, kj+nb );
auto A0L = A( ind0Vert, indL );
auto A1L = A( ind1Vert, indL );
auto phase1 = phase( ind1, ALL );
auto sig1 = signature( ind1, ALL );
PanelHouseholder( A1L, phase1, sig1 );
ApplyQ( RIGHT, ADJOINT, A1L, phase1, sig1, A0L );
}
}
void TestCorrectness
( bool print,
UpperOrLower uplo,
const ElementalMatrix<F>& AOrig,
const ElementalMatrix<F>& A,
const ElementalMatrix<Base<F>>& w,
const ElementalMatrix<F>& Z )
{
typedef Base<F> Real;
const Grid& g = A.Grid();
const Int n = Z.Height();
const Int k = Z.Width();
const Real eps = limits::Epsilon<Real>();
DistMatrix<F> X(g);
Identity( X, k, k );
Herk( uplo, ADJOINT, Real(-1), Z, Real(1), X );
const Real infOrthogError = HermitianInfinityNorm( uplo, X );
const Real relOrthogError = infOrthogError / (eps*n);
OutputFromRoot(g.Comm(),"||Z^H Z - I||_oo / (eps n) = ",relOrthogError);
// X := AZ
X.AlignWith( Z );
Zeros( X, n, k );
Hemm( LEFT, uplo, F(1), AOrig, Z, F(0), X );
// Find the residual ||X-ZW||_oo = ||AZ-ZW||_oo
DistMatrix<F> ZW( Z );
DiagonalScale( RIGHT, NORMAL, w, ZW );
X -= ZW;
const Real oneNormA = HermitianOneNorm( uplo, AOrig );
if( oneNormA == Real(0) )
LogicError("Tried to test relative accuracy on zero matrix...");
const Real infError = InfinityNorm( X );
const Real relError = infError / (n*eps*oneNormA);
OutputFromRoot(g.Comm(),"||A Z - Z W||_oo / (eps n ||A||_1) = ",relError);
// TODO: More refined failure conditions
if( relOrthogError > Real(200) ) // yes, really
LogicError("Relative orthogonality error was unacceptably large");
if( relError > Real(10) )
LogicError("Relative error was unacceptably large");
}
void
Householder
( ElementalMatrix<F>& APre,
ElementalMatrix<F>& phasePre,
ElementalMatrix<Base<F>>& signaturePre )
{
DEBUG_CSE
DEBUG_ONLY(AssertSameGrids( APre, phasePre, signaturePre ))
const Int m = APre.Height();
const Int n = APre.Width();
const Int minDim = Min(m,n);
DistMatrixReadWriteProxy<F,F,MC,MR> AProx( APre );
DistMatrixWriteProxy<F,F,MD,STAR> phaseProx( phasePre );
DistMatrixWriteProxy<Base<F>,Base<F>,MD,STAR> signatureProx( signaturePre );
auto& A = AProx.Get();
auto& phase = phaseProx.Get();
auto& signature = signatureProx.Get();
phase.Resize( minDim, 1 );
signature.Resize( minDim, 1 );
const Int bsize = Blocksize();
for( Int k=0; k<minDim; k+=bsize )
{
const Int nb = Min(bsize,minDim-k);
const Range<Int> ind1( k, k+nb ),
indB( k, END ),
ind2( k+nb, END );
auto AB1 = A( indB, ind1 );
auto AB2 = A( indB, ind2 );
auto phase1 = phase( ind1, ALL );
auto sig1 = signature( ind1, ALL );
PanelHouseholder( AB1, phase1, sig1 );
ApplyQ( LEFT, ADJOINT, AB1, phase1, sig1, AB2 );
}
}
void IndexDependentMap
( const ElementalMatrix<S>& A,
ElementalMatrix<T>& B,
function<T(Int,Int,S)> func )
{
DEBUG_CSE
const Int mLoc = A.LocalHeight();
const Int nLoc = A.LocalWidth();
B.AlignWith( A.DistData() );
B.Resize( A.Height(), A.Width() );
auto& ALoc = A.LockedMatrix();
auto& BLoc = B.Matrix();
for( Int jLoc=0; jLoc<nLoc; ++jLoc )
{
const Int j = A.GlobalCol(jLoc);
for( Int iLoc=0; iLoc<mLoc; ++iLoc )
{
const Int i = A.GlobalRow(iLoc);
BLoc(iLoc,jLoc) = func(i,j,ALoc(iLoc,jLoc));
}
}
}
void Gather
( const ElementalMatrix<T>& A,
DistMatrix<T,CIRC,CIRC>& B )
{
DEBUG_ONLY(CSE cse("copy::Gather"))
AssertSameGrids( A, B );
if( A.DistSize() == 1 && A.CrossSize() == 1 )
{
B.Resize( A.Height(), A.Width() );
if( B.CrossRank() == B.Root() )
Copy( A.LockedMatrix(), B.Matrix() );
return;
}
const Int height = A.Height();
const Int width = A.Width();
B.SetGrid( A.Grid() );
B.Resize( height, width );
// Gather the colShifts and rowShifts
// ==================================
Int myShifts[2];
myShifts[0] = A.ColShift();
myShifts[1] = A.RowShift();
vector<Int> shifts;
const Int crossSize = B.CrossSize();
if( B.CrossRank() == B.Root() )
shifts.resize( 2*crossSize );
mpi::Gather( myShifts, 2, shifts.data(), 2, B.Root(), B.CrossComm() );
// Gather the payload data
// =======================
const bool irrelevant = ( A.RedundantRank()!=0 || A.CrossRank()!=A.Root() );
int totalSend = ( irrelevant ? 0 : A.LocalHeight()*A.LocalWidth() );
vector<int> recvCounts, recvOffsets;
if( B.CrossRank() == B.Root() )
recvCounts.resize( crossSize );
mpi::Gather( &totalSend, 1, recvCounts.data(), 1, B.Root(), B.CrossComm() );
int totalRecv = Scan( recvCounts, recvOffsets );
//vector<T> sendBuf(totalSend), recvBuf(totalRecv);
vector<T> sendBuf, recvBuf;
sendBuf.reserve( totalSend );
recvBuf.reserve( totalRecv );
if( !irrelevant )
copy::util::InterleaveMatrix
( A.LocalHeight(), A.LocalWidth(),
A.LockedBuffer(), 1, A.LDim(),
sendBuf.data(), 1, A.LocalHeight() );
mpi::Gather
( sendBuf.data(), totalSend,
recvBuf.data(), recvCounts.data(), recvOffsets.data(),
B.Root(), B.CrossComm() );
// Unpack
// ======
if( B.Root() == B.CrossRank() )
{
for( Int q=0; q<crossSize; ++q )
{
if( recvCounts[q] == 0 )
continue;
const Int colShift = shifts[2*q+0];
const Int rowShift = shifts[2*q+1];
const Int colStride = A.ColStride();
const Int rowStride = A.RowStride();
const Int localHeight = Length( height, colShift, colStride );
const Int localWidth = Length( width, rowShift, rowStride );
copy::util::InterleaveMatrix
( localHeight, localWidth,
&recvBuf[recvOffsets[q]], 1, localHeight,
B.Buffer(colShift,rowShift), colStride, rowStride*B.LDim() );
}
}
}
void LUMod
( ElementalMatrix<F>& APre,
DistPermutation& P,
const ElementalMatrix<F>& u,
const ElementalMatrix<F>& v,
bool conjugate,
Base<F> tau )
{
DEBUG_CSE
const Grid& g = APre.Grid();
typedef Base<F> Real;
DistMatrixReadWriteProxy<F,F,MC,MR> AProx( APre );
auto& A = AProx.Get();
const Int m = A.Height();
const Int n = A.Width();
const Int minDim = Min(m,n);
if( minDim != m )
LogicError("It is assumed that height(A) <= width(A)");
if( u.Height() != m || u.Width() != 1 )
LogicError("u is expected to be a conforming column vector");
if( v.Height() != n || v.Width() != 1 )
LogicError("v is expected to be a conforming column vector");
AssertSameGrids( A, u, v );
// w := inv(L) P u
// TODO: Consider locally maintaining all of w to avoid unnecessarily
// broadcasting at every iteration.
DistMatrix<F> w( u );
P.PermuteRows( w );
Trsv( LOWER, NORMAL, UNIT, A, w );
// Maintain an external vector for the temporary subdiagonal of U
DistMatrix<F,MD,STAR> uSub(g);
uSub.SetRoot( A.DiagonalRoot(-1) );
uSub.AlignCols( A.DiagonalAlign(-1) );
Zeros( uSub, minDim-1, 1 );
// Reduce w to a multiple of e0
for( Int i=minDim-2; i>=0; --i )
{
// Decide if we should pivot the i'th and i+1'th rows of w
const F lambdaSub = A.Get(i+1,i);
const F ups_ii = A.Get(i,i);
const F omega_i = w.Get( i, 0 );
const F omega_ip1 = w.Get( i+1, 0 );
const Real rightTerm = Abs(lambdaSub*omega_i+omega_ip1);
const bool pivot = ( Abs(omega_i) < tau*rightTerm );
const Range<Int> indB( i+2, m ),
indR( i+1, n ),
indi( i, i+1 ),
indip1( i+1, i+2 );
auto lBi = A( indB, indi );
auto lBip1 = A( indB, indip1 );
auto uiR = A( indi, indR );
auto uip1R = A( indip1, indR );
if( pivot )
{
// P := P_i P
P.Swap( i, i+1 );
// Simultaneously perform
// U := P_i U and
// L := P_i L P_i^T
//
// Then update
// L := L T_{i,L}^{-1},
// U := T_{i,L} U,
// w := T_{i,L} P_i w,
// where T_{i,L} is the Gauss transform which zeros (P_i w)_{i+1}.
//
// More succinctly,
// gamma := w(i) / w(i+1),
// w(i) := w(i+1),
// w(i+1) := 0,
// L(:,i) += gamma L(:,i+1),
// U(i+1,:) -= gamma U(i,:).
const F gamma = omega_i / omega_ip1;
const F lambda_ii = F(1) + gamma*lambdaSub;
A.Set( i, i, gamma );
A.Set( i+1, i, 0 );
auto lBiCopy = lBi;
Swap( NORMAL, lBi, lBip1 );
Axpy( gamma, lBiCopy, lBi );
auto uip1RCopy = uip1R;
RowSwap( A, i, i+1 );
Axpy( -gamma, uip1RCopy, uip1R );
// Force L back to *unit* lower-triangular form via the transform
// L := L T_{i,U}^{-1} D^{-1},
// where D is diagonal and responsible for forcing L(i,i) and
// L(i+1,i+1) back to 1. The effect on L is:
// eta := L(i,i+1)/L(i,i),
// L(:,i+1) -= eta L(:,i),
// delta_i := L(i,i),
// delta_ip1 := L(i+1,i+1),
// L(:,i) /= delta_i,
// L(:,i+1) /= delta_ip1,
// while the effect on U is
// U(i,:) += eta U(i+1,:)
// U(i,:) *= delta_i,
// U(i+1,:) *= delta_{i+1},
// and the effect on w is
// w(i) *= delta_i.
const F eta = lambdaSub/lambda_ii;
const F delta_i = lambda_ii;
const F delta_ip1 = F(1) - eta*gamma;
Axpy( -eta, lBi, lBip1 );
A.Set( i+1, i, gamma/delta_i );
lBi *= F(1)/delta_i;
lBip1 *= F(1)/delta_ip1;
A.Set( i, i, eta*ups_ii*delta_i );
Axpy( eta, uip1R, uiR );
uiR *= delta_i;
uip1R *= delta_ip1;
uSub.Set( i, 0, ups_ii*delta_ip1 );
// Finally set w(i)
w.Set( i, 0, omega_ip1*delta_i );
}
else
{
// Update
// L := L T_{i,L}^{-1},
// U := T_{i,L} U,
// w := T_{i,L} w,
// where T_{i,L} is the Gauss transform which zeros w_{i+1}.
//
// More succinctly,
// gamma := w(i+1) / w(i),
// L(:,i) += gamma L(:,i+1),
// U(i+1,:) -= gamma U(i,:),
// w(i+1) := 0.
const F gamma = omega_ip1 / omega_i;
A.Update( i+1, i, gamma );
Axpy( gamma, lBip1, lBi );
Axpy( -gamma, uiR, uip1R );
uSub.Set( i, 0, -gamma*ups_ii );
}
}
// Add the modified w v' into U
{
auto a0 = A( IR(0), ALL );
const F omega_0 = w.Get( 0, 0 );
DistMatrix<F> vTrans(g);
vTrans.AlignWith( a0 );
Transpose( v, vTrans, conjugate );
Axpy( omega_0, vTrans, a0 );
}
// Transform U from upper-Hessenberg to upper-triangular form
for( Int i=0; i<minDim-1; ++i )
{
// Decide if we should pivot the i'th and i+1'th rows U
const F lambdaSub = A.Get( i+1, i );
const F ups_ii = A.Get( i, i );
const F ups_ip1i = uSub.Get( i, 0 );
const Real rightTerm = Abs(lambdaSub*ups_ii+ups_ip1i);
const bool pivot = ( Abs(ups_ii) < tau*rightTerm );
const Range<Int> indB( i+2, m ),
indR( i+1, n ),
indi( i, i+1 ),
indip1( i+1, i+2 );
auto lBi = A( indB, indi );
auto lBip1 = A( indB, indip1 );
auto uiR = A( indi, indR );
auto uip1R = A( indip1, indR );
if( pivot )
{
// P := P_i P
P.Swap( i, i+1 );
// Simultaneously perform
// U := P_i U and
// L := P_i L P_i^T
//
// Then update
// L := L T_{i,L}^{-1},
// U := T_{i,L} U,
// where T_{i,L} is the Gauss transform which zeros U(i+1,i).
//
// More succinctly,
// gamma := U(i+1,i) / U(i,i),
// L(:,i) += gamma L(:,i+1),
// U(i+1,:) -= gamma U(i,:).
const F gamma = ups_ii / ups_ip1i;
const F lambda_ii = F(1) + gamma*lambdaSub;
A.Set( i+1, i, ups_ip1i );
A.Set( i, i, gamma );
auto lBiCopy = lBi;
Swap( NORMAL, lBi, lBip1 );
Axpy( gamma, lBiCopy, lBi );
auto uip1RCopy = uip1R;
RowSwap( A, i, i+1 );
Axpy( -gamma, uip1RCopy, uip1R );
// Force L back to *unit* lower-triangular form via the transform
// L := L T_{i,U}^{-1} D^{-1},
// where D is diagonal and responsible for forcing L(i,i) and
// L(i+1,i+1) back to 1. The effect on L is:
// eta := L(i,i+1)/L(i,i),
// L(:,i+1) -= eta L(:,i),
// delta_i := L(i,i),
// delta_ip1 := L(i+1,i+1),
// L(:,i) /= delta_i,
// L(:,i+1) /= delta_ip1,
// while the effect on U is
// U(i,:) += eta U(i+1,:)
// U(i,:) *= delta_i,
// U(i+1,:) *= delta_{i+1}.
const F eta = lambdaSub/lambda_ii;
const F delta_i = lambda_ii;
const F delta_ip1 = F(1) - eta*gamma;
Axpy( -eta, lBi, lBip1 );
A.Set( i+1, i, gamma/delta_i );
lBi *= F(1)/delta_i;
lBip1 *= F(1)/delta_ip1;
A.Set( i, i, ups_ip1i*delta_i );
Axpy( eta, uip1R, uiR );
uiR *= delta_i;
uip1R *= delta_ip1;
}
else
{
// Update
// L := L T_{i,L}^{-1},
// U := T_{i,L} U,
// where T_{i,L} is the Gauss transform which zeros U(i+1,i).
//
// More succinctly,
// gamma := U(i+1,i)/ U(i,i),
// L(:,i) += gamma L(:,i+1),
// U(i+1,:) -= gamma U(i,:).
const F gamma = ups_ip1i / ups_ii;
A.Update( i+1, i, gamma );
Axpy( gamma, lBip1, lBi );
Axpy( -gamma, uiR, uip1R );
}
}
}
void ApplyQ
( LeftOrRight side,
Orientation orientation,
const ElementalMatrix<F>& APre,
const ElementalMatrix<F>& phasePre,
const ElementalMatrix<Base<F>>& signature,
ElementalMatrix<F>& BPre )
{
DEBUG_CSE
const bool normal = (orientation==NORMAL);
const bool onLeft = (side==LEFT);
const bool applyDFirst = normal!=onLeft;
const Int minDim = Min(APre.Height(),APre.Width());
const ForwardOrBackward direction = ( normal==onLeft ? FORWARD : BACKWARD );
const Conjugation conjugation = ( normal ? CONJUGATED : UNCONJUGATED );
DistMatrixReadProxy<F,F,MC,MR> AProx( APre );
DistMatrixReadWriteProxy<F,F,MC,MR> BProx( BPre );
auto& A = AProx.GetLocked();
auto& B = BProx.Get();
ElementalProxyCtrl phaseCtrl;
phaseCtrl.rootConstrain = true;
phaseCtrl.colConstrain = true;
phaseCtrl.root = A.DiagonalRoot();
phaseCtrl.colAlign = A.DiagonalAlign();
DistMatrixReadProxy<F,F,MD,STAR> phaseProx( phasePre, phaseCtrl );
auto& phase = phaseProx.GetLocked();
const Int m = B.Height();
const Int n = B.Width();
if( applyDFirst )
{
if( onLeft )
{
auto BTop = B( IR(0,minDim), IR(0,n) );
DiagonalScale( side, orientation, signature, BTop );
}
else
{
auto BLeft = B( IR(0,m), IR(0,minDim) );
DiagonalScale( side, orientation, signature, BLeft );
}
}
ApplyPackedReflectors
( side, UPPER, HORIZONTAL, direction, conjugation, 0, A, phase, B );
if( !applyDFirst )
{
if( onLeft )
{
auto BTop = B( IR(0,minDim), IR(0,n) );
DiagonalScale( side, orientation, signature, BTop );
}
else
{
auto BLeft = B( IR(0,m), IR(0,minDim) );
DiagonalScale( side, orientation, signature, BLeft );
}
}
}
void Tikhonov
( Orientation orientation,
const ElementalMatrix<F>& APre,
const ElementalMatrix<F>& BPre,
const ElementalMatrix<F>& G,
ElementalMatrix<F>& XPre,
TikhonovAlg alg )
{
DEBUG_CSE
DistMatrixReadProxy<F,F,MC,MR>
AProx( APre ),
BProx( BPre );
DistMatrixWriteProxy<F,F,MC,MR>
XProx( XPre );
auto& A = AProx.GetLocked();
auto& B = BProx.GetLocked();
auto& X = XProx.Get();
const bool normal = ( orientation==NORMAL );
const Int m = ( normal ? A.Height() : A.Width() );
const Int n = ( normal ? A.Width() : A.Height() );
if( G.Width() != n )
LogicError("Tikhonov matrix was the wrong width");
if( orientation == TRANSPOSE && IsComplex<F>::value )
LogicError("Transpose version of complex Tikhonov not yet supported");
if( m >= n )
{
DistMatrix<F> Z(A.Grid());
if( alg == TIKHONOV_CHOLESKY )
{
if( orientation == NORMAL )
Herk( LOWER, ADJOINT, Base<F>(1), A, Z );
else
Herk( LOWER, NORMAL, Base<F>(1), A, Z );
Herk( LOWER, ADJOINT, Base<F>(1), G, Base<F>(1), Z );
Cholesky( LOWER, Z );
}
else
{
const Int mG = G.Height();
Zeros( Z, m+mG, n );
auto ZT = Z( IR(0,m), IR(0,n) );
auto ZB = Z( IR(m,m+mG), IR(0,n) );
if( orientation == NORMAL )
ZT = A;
else
Adjoint( A, ZT );
ZB = G;
qr::ExplicitTriang( Z );
}
if( orientation == NORMAL )
Gemm( ADJOINT, NORMAL, F(1), A, B, X );
else
Gemm( NORMAL, NORMAL, F(1), A, B, X );
cholesky::SolveAfter( LOWER, NORMAL, Z, X );
}
else
{
LogicError("This case not yet supported");
}
}
void ColScatter
( T alpha,
const ElementalMatrix<T>& A,
ElementalMatrix<T>& B )
{
DEBUG_ONLY(CSE cse("axpy_contract::ColScatter"))
AssertSameGrids( A, B );
if( A.Height() != B.Height() || A.Width() != B.Width() )
LogicError("A and B must be the same size");
#ifdef EL_VECTOR_WARNINGS
if( A.Width() == 1 && B.Grid().Rank() == 0 )
{
cerr <<
"The vector version of ColScatter does not"
" yet have a vector version implemented, but it would only "
"require a modification of the vector version of RowScatter"
<< endl;
}
#endif
#ifdef EL_CACHE_WARNINGS
if( A.Width() != 1 && B.Grid().Rank() == 0 )
{
cerr <<
"axpy_contract::ColScatter potentially causes a large "
"amount of cache-thrashing. If possible, avoid it by forming the "
"(conjugate-)transpose of the [* ,V] matrix instead." << endl;
}
#endif
if( !B.Participating() )
return;
const Int height = B.Height();
const Int localHeight = B.LocalHeight();
const Int localWidth = B.LocalWidth();
const Int colAlign = B.ColAlign();
const Int colStride = B.ColStride();
const Int rowDiff = B.RowAlign()-A.RowAlign();
// TODO: Allow for modular equivalence if possible
if( rowDiff == 0 )
{
const Int maxLocalHeight = MaxLength(height,colStride);
const Int recvSize = mpi::Pad( maxLocalHeight*localWidth );
const Int sendSize = colStride*recvSize;
//vector<T> buffer( sendSize );
vector<T> buffer;
buffer.reserve( sendSize );
// Pack
copy::util::ColStridedPack
( height, localWidth,
colAlign, colStride,
A.LockedBuffer(), A.LDim(),
buffer.data(), recvSize );
// Communicate
mpi::ReduceScatter( buffer.data(), recvSize, B.ColComm() );
// Update with our received data
axpy::util::InterleaveMatrixUpdate
( alpha, localHeight, localWidth,
buffer.data(), 1, localHeight,
B.Buffer(), 1, B.LDim() );
}
else
{
#ifdef EL_UNALIGNED_WARNINGS
if( B.Grid().Rank() == 0 )
cerr << "Unaligned ColScatter" << endl;
#endif
const Int localWidthA = A.LocalWidth();
const Int maxLocalHeight = MaxLength(height,colStride);
const Int recvSize_RS = mpi::Pad( maxLocalHeight*localWidthA );
const Int sendSize_RS = colStride*recvSize_RS;
const Int recvSize_SR = localHeight*localWidth;
//vector<T> buffer( recvSize_RS + Max(sendSize_RS,recvSize_SR) );
vector<T> buffer;
buffer.reserve( recvSize_RS + Max(sendSize_RS,recvSize_SR) );
T* firstBuf = &buffer[0];
T* secondBuf = &buffer[recvSize_RS];
// Pack
copy::util::ColStridedPack
( height, localWidth,
colAlign, colStride,
A.LockedBuffer(), A.LDim(),
secondBuf, recvSize_RS );
// Reduce-scatter over each col
mpi::ReduceScatter( secondBuf, firstBuf, recvSize_RS, B.ColComm() );
// Trade reduced data with the appropriate col
const Int sendCol = Mod( B.RowRank()+rowDiff, B.RowStride() );
const Int recvCol = Mod( B.RowRank()-rowDiff, B.RowStride() );
mpi::SendRecv
( firstBuf, localHeight*localWidthA, sendCol,
secondBuf, localHeight*localWidth, recvCol, B.RowComm() );
// Update with our received data
axpy::util::InterleaveMatrixUpdate
( alpha, localHeight, localWidth,
secondBuf, 1, localHeight,
B.Buffer(), 1, B.LDim() );
}
}
void RowScatter
( T alpha,
const ElementalMatrix<T>& A,
ElementalMatrix<T>& B )
{
DEBUG_ONLY(CSE cse("axpy_contract::RowScatter"))
AssertSameGrids( A, B );
if( A.Height() != B.Height() || A.Width() != B.Width() )
LogicError("Matrix sizes did not match");
if( !B.Participating() )
return;
const Int width = B.Width();
const Int colDiff = B.ColAlign()-A.ColAlign();
if( colDiff == 0 )
{
if( width == 1 )
{
const Int localHeight = B.LocalHeight();
const Int portionSize = mpi::Pad( localHeight );
//vector<T> buffer( portionSize );
vector<T> buffer;
buffer.reserve( portionSize );
// Reduce to rowAlign
const Int rowAlign = B.RowAlign();
mpi::Reduce
( A.LockedBuffer(), buffer.data(), portionSize,
rowAlign, B.RowComm() );
if( B.RowRank() == rowAlign )
{
axpy::util::InterleaveMatrixUpdate
( alpha, localHeight, 1,
buffer.data(), 1, localHeight,
B.Buffer(), 1, B.LDim() );
}
}
else
{
const Int rowStride = B.RowStride();
const Int rowAlign = B.RowAlign();
const Int localHeight = B.LocalHeight();
const Int localWidth = B.LocalWidth();
const Int maxLocalWidth = MaxLength(width,rowStride);
const Int portionSize = mpi::Pad( localHeight*maxLocalWidth );
const Int sendSize = rowStride*portionSize;
// Pack
//vector<T> buffer( sendSize );
vector<T> buffer;
buffer.reserve( sendSize );
copy::util::RowStridedPack
( localHeight, width,
rowAlign, rowStride,
A.LockedBuffer(), A.LDim(),
buffer.data(), portionSize );
// Communicate
mpi::ReduceScatter( buffer.data(), portionSize, B.RowComm() );
// Update with our received data
axpy::util::InterleaveMatrixUpdate
( alpha, localHeight, localWidth,
buffer.data(), 1, localHeight,
B.Buffer(), 1, B.LDim() );
}
}
else
{
#ifdef EL_UNALIGNED_WARNINGS
if( B.Grid().Rank() == 0 )
cerr << "Unaligned RowScatter" << endl;
#endif
const Int colRank = B.ColRank();
const Int colStride = B.ColStride();
const Int sendRow = Mod( colRank+colDiff, colStride );
const Int recvRow = Mod( colRank-colDiff, colStride );
const Int localHeight = B.LocalHeight();
const Int localHeightA = A.LocalHeight();
if( width == 1 )
{
//vector<T> buffer( localHeight+localHeightA );
vector<T> buffer;
buffer.reserve( localHeight+localHeightA );
T* sendBuf = &buffer[0];
T* recvBuf = &buffer[localHeightA];
// Reduce to rowAlign
const Int rowAlign = B.RowAlign();
mpi::Reduce
( A.LockedBuffer(), sendBuf, localHeightA, rowAlign, B.RowComm() );
if( B.RowRank() == rowAlign )
{
// Perform the realignment
mpi::SendRecv
( sendBuf, localHeightA, sendRow,
recvBuf, localHeight, recvRow, B.ColComm() );
axpy::util::InterleaveMatrixUpdate
( alpha, localHeight, 1,
recvBuf, 1, localHeight,
B.Buffer(), 1, B.LDim() );
}
}
else
{
const Int rowStride = B.RowStride();
const Int rowAlign = B.RowAlign();
const Int localWidth = B.LocalWidth();
const Int maxLocalWidth = MaxLength(width,rowStride);
const Int recvSize_RS = mpi::Pad( localHeightA*maxLocalWidth );
const Int sendSize_RS = rowStride * recvSize_RS;
const Int recvSize_SR = localHeight * localWidth;
//vector<T> buffer( recvSize_RS + Max(sendSize_RS,recvSize_SR) );
vector<T> buffer;
buffer.reserve( recvSize_RS + Max(sendSize_RS,recvSize_SR) );
T* firstBuf = &buffer[0];
T* secondBuf = &buffer[recvSize_RS];
// Pack
copy::util::RowStridedPack
( localHeightA, width,
rowAlign, rowStride,
A.LockedBuffer(), A.LDim(),
secondBuf, recvSize_RS );
// Reduce-scatter over each process row
mpi::ReduceScatter( secondBuf, firstBuf, recvSize_RS, B.RowComm() );
// Trade reduced data with the appropriate process row
mpi::SendRecv
( firstBuf, localHeightA*localWidth, sendRow,
secondBuf, localHeight*localWidth, recvRow, B.ColComm() );
// Update with our received data
axpy::util::InterleaveMatrixUpdate
( alpha, localHeight, localWidth,
secondBuf, 1, localHeight,
B.Buffer(), 1, B.LDim() );
}
}
}
void SolveAfter
( Orientation orientation,
const ElementalMatrix<F>& APre,
const ElementalMatrix<F>& householderScalars,
const ElementalMatrix<Base<F>>& signature,
const ElementalMatrix<F>& B,
ElementalMatrix<F>& XPre )
{
DEBUG_CSE
const Int m = APre.Height();
const Int n = APre.Width();
if( m > n )
LogicError("Must have full row rank");
DistMatrixReadProxy<F,F,MC,MR> AProx( APre );
DistMatrixWriteProxy<F,F,MC,MR> XProx( XPre );
auto& A = AProx.GetLocked();
auto& X = XProx.Get();
X.Resize( n, B.Width() );
// TODO: Add scaling
auto AL = A( IR(0,m), IR(0,m) );
if( orientation == NORMAL )
{
if( m != B.Height() )
LogicError("A and B do not conform");
// Copy B into X
auto XT = X( IR(0,m), ALL );
auto XB = X( IR(m,n), ALL );
XT = B;
Zero( XB );
if( orientation == TRANSPOSE )
Conjugate( XT );
// Solve against L (checking for singularities)
Trsm( LEFT, LOWER, NORMAL, NON_UNIT, F(1), AL, XT, true );
// Apply Q' to X
lq::ApplyQ( LEFT, ADJOINT, A, householderScalars, signature, X );
if( orientation == TRANSPOSE )
Conjugate( X );
}
else
{
// Copy B into X
X = B;
if( orientation == TRANSPOSE )
Conjugate( X );
// Apply Q to X
lq::ApplyQ( LEFT, NORMAL, A, householderScalars, signature, X );
// Shrink X to its new height
X.Resize( m, X.Width() );
// Solve against L' (check for singularities)
Trsm( LEFT, LOWER, ADJOINT, NON_UNIT, F(1), AL, X, true );
if( orientation == TRANSPOSE )
Conjugate( X );
}
}