swaps.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_SWAPS_H
#define MYRAMATH_DENSE_SWAPS_H

#include <myramath/MYRAMATH_EXPORT.h>

#include <myramath/utility/Number.h>
#include <myramath/utility/eprintf.h>
#include <myramath/utility/detail/ssize.h>
#include <myramath/utility/detail/sdistance.h>

#include <myramath/dense/intRange.h>

#include <vector>

namespace myra {

// Forward declarations.
class intRange;
class intCRange;
template<class Number> class VectorRange;
template<class Number> class MatrixRange;
template<class Number> class Matrix;

// --------------------------------------- Generating and manipulating permutations.

MYRAMATH_EXPORT void inverse_perm(const intCRange& perm, const intRange& iperm);
MYRAMATH_EXPORT std::vector<int> inverse_perm(const intCRange& perm);

MYRAMATH_EXPORT void swaps2iswaps(const intCRange& swaps, const intRange& iswaps);
MYRAMATH_EXPORT std::vector<int> swaps2iswaps(const intCRange& swaps);

MYRAMATH_EXPORT void perm2swaps(const intCRange& perm, const intRange& swaps);
MYRAMATH_EXPORT std::vector<int> perm2swaps(const intCRange& perm);

MYRAMATH_EXPORT void swaps2perm (const intCRange& swaps, const intRange& perm);
MYRAMATH_EXPORT std::vector<int> swaps2perm (const intCRange& swaps);

// .. same result to inverse_perm(swaps2perm(swaps)), but more efficient
MYRAMATH_EXPORT void swaps2iperm (const intCRange& swaps, const intRange& perm);
MYRAMATH_EXPORT std::vector<int> swaps2iperm (const intCRange& swaps);

template<class Number> Matrix<Number> swaps2Matrix (const intCRange& swaps);
template<> MYRAMATH_EXPORT Matrix<NumberS> swaps2Matrix<NumberS> (const intCRange& swaps);
template<> MYRAMATH_EXPORT Matrix<NumberD> swaps2Matrix<NumberD> (const intCRange& swaps);
template<> MYRAMATH_EXPORT Matrix<NumberC> swaps2Matrix<NumberC> (const intCRange& swaps);
template<> MYRAMATH_EXPORT Matrix<NumberZ> swaps2Matrix<NumberZ> (const intCRange& swaps);

// --------------------------------------- Applying swap sequences to numeric containers.

MYRAMATH_EXPORT void swap_rows(const intCRange& swaps, const MatrixRange<NumberS>& X);
MYRAMATH_EXPORT void swap_rows(const intCRange& swaps, const MatrixRange<NumberD>& X);
MYRAMATH_EXPORT void swap_rows(const intCRange& swaps, const MatrixRange<NumberC>& X);
MYRAMATH_EXPORT void swap_rows(const intCRange& swaps, const MatrixRange<NumberZ>& X);

MYRAMATH_EXPORT void iswap_rows(const intCRange& swaps, const MatrixRange<NumberS>& X);
MYRAMATH_EXPORT void iswap_rows(const intCRange& swaps, const MatrixRange<NumberD>& X);
MYRAMATH_EXPORT void iswap_rows(const intCRange& swaps, const MatrixRange<NumberC>& X);
MYRAMATH_EXPORT void iswap_rows(const intCRange& swaps, const MatrixRange<NumberZ>& X);

MYRAMATH_EXPORT void swap_columns(const intCRange& swaps, const MatrixRange<NumberS>& X);
MYRAMATH_EXPORT void swap_columns(const intCRange& swaps, const MatrixRange<NumberD>& X);
MYRAMATH_EXPORT void swap_columns(const intCRange& swaps, const MatrixRange<NumberC>& X);
MYRAMATH_EXPORT void swap_columns(const intCRange& swaps, const MatrixRange<NumberZ>& X);

MYRAMATH_EXPORT void iswap_columns(const intCRange& swaps, const MatrixRange<NumberS>& X);
MYRAMATH_EXPORT void iswap_columns(const intCRange& swaps, const MatrixRange<NumberD>& X);
MYRAMATH_EXPORT void iswap_columns(const intCRange& swaps, const MatrixRange<NumberC>& X);
MYRAMATH_EXPORT void iswap_columns(const intCRange& swaps, const MatrixRange<NumberZ>& X);

MYRAMATH_EXPORT void swap_vector(const intCRange& swaps, const VectorRange<NumberS>& x);
MYRAMATH_EXPORT void swap_vector(const intCRange& swaps, const VectorRange<NumberD>& x);
MYRAMATH_EXPORT void swap_vector(const intCRange& swaps, const VectorRange<NumberC>& x);
MYRAMATH_EXPORT void swap_vector(const intCRange& swaps, const VectorRange<NumberZ>& x);

MYRAMATH_EXPORT void swap_vector(const intCRange& swaps, const intRange& x);

MYRAMATH_EXPORT void iswap_vector(const intCRange& swaps, const VectorRange<NumberS>& x);
MYRAMATH_EXPORT void iswap_vector(const intCRange& swaps, const VectorRange<NumberD>& x);
MYRAMATH_EXPORT void iswap_vector(const intCRange& swaps, const VectorRange<NumberC>& x);
MYRAMATH_EXPORT void iswap_vector(const intCRange& swaps, const VectorRange<NumberZ>& x);

MYRAMATH_EXPORT void iswap_vector(const intCRange& swaps, const intRange& x);


template<class T> void swap_range(const intCRange& swaps, T* begin, T* end)
  {
  if (swaps.N != sdistance(begin,end))
    throw eprintf("swap_range(): size mismatch, swaps.N != range size [%d != %d]", swaps.N, sdistance(begin,end));
  int N = swaps.N;
  for (int n = 0; n < N; ++n)
    std::swap( begin[n], begin[swaps[n]] );
  }

template<class T> void iswap_range(const intCRange& swaps, T* begin, T* end)
  {
  if (swaps.N != sdistance(begin,end))
    throw eprintf("iswap_range(): size mismatch, swaps.N != range size [%d != %d]", swaps.N, sdistance(begin,end));
  int N = swaps.N;
  for (int n = N-1; n >= 0; --n)
    std::swap( begin[n], begin[swaps[n]] ); 
  }

template<class T> void swap_vector(const intCRange& swaps, std::vector<T>& v)
  { swap_range(swaps, v.data(),v.data()+v.size() ); }

template<class T> void iswap_vector(const intCRange& swaps, std::vector<T>& v)
  { iswap_range(swaps, v.data(),v.data()+v.size() ); }


} // namespace

#endif