hetrf.h

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// ========================================================================= //
// This file is part of MyraMath, copyright (c) 2014-2019 by Ryan A Chilton  //
// and distributed by MyraCore, LLC. See LICENSE.txt for license terms.      //
// ========================================================================= //

#ifndef MYRAMATH_DENSE_HETRF_H
#define MYRAMATH_DENSE_HETRF_H

#include <myramath/MYRAMATH_EXPORT.h>
#include <myramath/utility/Number.h>

#include <myramath/dense/LDLSwaps.h>

namespace myra {

// Forward declarations.
template <class Number> class MatrixRange;
template <class Number> class LowerMatrixRange;

//
// Four different choices for uplo/side, each has a slightly different effect.
// Uplo controls whether the 'U'pper or 'L'ower triangle is accessed, and side 
// controls whether the transpose' appears on the 'L'eft or 'R'ight triangle:
//
//   uplo = 'L', side = 'R' -> factors A = P'*L *R *Q'*I*Q*R'*L'*P
//   uplo = 'L', side = 'L' -> factors A = P'*L'*R'*Q'*I*Q*R *L *P
//   uplo = 'U', side = 'R' -> factors A = P'*U *R *Q'*I*Q*R'*U'*P
//   uplo = 'U', side = 'L' -> factors A = P'*U'*R'*Q'*I*Q*R *U *P
//
MYRAMATH_EXPORT LDLSwaps<NumberC> hetrf_inplace(char uplo, char side, const MatrixRange<NumberC>& A);
MYRAMATH_EXPORT LDLSwaps<NumberZ> hetrf_inplace(char uplo, char side, const MatrixRange<NumberZ>& A);

MYRAMATH_EXPORT LDLSwaps<NumberC> hetrf_inplace(const LowerMatrixRange<NumberC>& A);
MYRAMATH_EXPORT LDLSwaps<NumberZ> hetrf_inplace(const LowerMatrixRange<NumberZ>& A);

// Makes a deep copy into a square Matrix, then calls hetrf_inplace(MatrixRange). More stable 
// than hetrf_inplace(LowerMatrixRange), because of more of the system is available for pivoting.
MYRAMATH_EXPORT LDLSwaps<NumberC> hetrf_outplace(const LowerMatrixRange<NumberC>& A);
MYRAMATH_EXPORT LDLSwaps<NumberZ> hetrf_outplace(const LowerMatrixRange<NumberZ>& A);

} // namespace

#endif