/usr/include/linbox/switch/cekstv.h is in liblinbox-dev 1.3.2-1.1build2.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 | /* linbox/switch/cekstv.h
* Copyright (C) 1999-2001 William J Turner
*
* Written by William J Turner <wjturner@math.ncsu.edu>
*
* -----------------------------------------------------------
* 2002-09-26 Bradford Hovinen <bghovinen@math.uwaterloo.ca>
*
* Refactoring: The switch object now contains only the information for one 2x2
* block. A vector of switches is maintained by the butterfly preconditioner
* instead of the switch object. Since there will be many switch objects, they
* should be kept very lightweight, so the field is not maintained in the object
* itself, but instead passed to apply and applyTranspose. Since those methods
* are inline, this does not create overhead. apply and applyTranspose now take
* four field elements: the source elements and destination elements. This
* eliminates the need to keep an additional temporary in the class, and
* eliminates the need for copying in the butterfly.
*
* -----------------------------------------------------------
* 2002-08-20 Bradford Hovinen <hovinen@cis.udel.edu>
*
* Brought this file into the current Linbox framework:
* - Renamed file as cekstv.h
* - Renamed class cekstv_switch as CekstvSwitch
* - Reindent
* -----------------------------------------------------------
*
*
* ========LICENCE========
* This file is part of the library LinBox.
*
* LinBox is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
* ========LICENCE========
*.
*/
#ifndef __LINBOX_cekstv_H
#define __LINBOX_cekstv_H
#include <vector>
namespace LinBox
{
template <class Field>
class CekstvSwitchFactory;
/** Butterfly switch object from preconditioner paper.
* This is a switch predicate object that is applied
* to two references to elements to switch them as needed
* by the \ref Butterfly\ Switching\ Network\ BlackBox\ Matrix\ Object
* following the exchange matrix introduced in "Efficient Matrix
* Preconditioners for Black Box Linear Algebra" by Chen, Eberly,
* Kaltofen, Saunders, Turner, and Villard.
* This class is templatized by the field in which the arithmetic
* is done.
*/
template <class Field>
class CekstvSwitch {
public:
/// Typedef
typedef typename Field::Element Element;
typedef CekstvSwitch<Field> Self_t;
typedef CekstvSwitchFactory<Field> Factory;
CekstvSwitch () {}
/** Constructor from a field and a field element.
* @param a vector of switches
*/
CekstvSwitch (const typename Field::Element &a) :
_a (a)
{}
/** Destructor.
*/
~CekstvSwitch () {}
/** Apply switch function.
* Switches the elements in references according to the
* exchange matrix introduced in "Efficient Matrix
* Preconditioners for Black Box Linear Algebra" by Chen, Eberly,
* Kaltofen, Saunders, Turner, and Villard and the current field element
* specified in the switch object.
* @return bool true if swapped, false otherwise
* @param F
* @param x reference to first element to be switched
* @param y reference to second element to be switched
*/
bool apply (const Field &F, Element &x, Element &y) const;
/** Apply switch transpose function.
* Switches the elements in references according to the
* transpose of the exchange matrix introduced in "Efficient Matrix
* Preconditioners for Black Box Linear Algebra" by Chen, Eberly,
* Kaltofen, Saunders, Turner, and Villard and the current field element
* specified in the switch object.
* @return bool true if swapped, false otherwise
* @param F
* @param x reference to first element to be switched
* @param y reference to second element to be switched
*/
bool applyTranspose (const Field &F, Element &x, Element &y) const;
template<typename _Tp1>
struct rebind
{
typedef CekstvSwitch<_Tp1> other;
// special rebind operator() with two fields,
// indeed local field is not stored in the switch
void operator() (other & Ap, const Self_t& A, const _Tp1& T, const Field& F) {
Hom<Field, _Tp1>(F,T).image(Ap.getData(), A.getData());
}
};
typename Field::Element& getData() { return _a; }
const typename Field::Element& getData() const { return _a; }
private:
// Parameter of this 2x2 block
typename Field::Element _a;
};
/** Cekstv switch factory
*
* This class facilitates construction of cekstv switch objects by the
* butterfly matrix.
*/
template <class Field>
class CekstvSwitchFactory {
public:
/** Constructor from an STL vector of bools
*/
CekstvSwitchFactory (typename Field::RandIter r) :
_r (r)
{}
/** Construct and return a boolean switch object
*/
CekstvSwitch<Field> makeSwitch ()
{ typename Field::Element a; return CekstvSwitch<Field> (_r.random (a)); }
private:
typename Field::RandIter _r;
};
template <class Field>
inline bool CekstvSwitch<Field>::apply (const Field &F,
typename Field::Element &x,
typename Field::Element &y) const
{
F.axpyin (x, _a, y);
F.addin (y, x);
return true;
}
template <class Field>
inline bool CekstvSwitch<Field>::applyTranspose (const Field &F,
typename Field::Element &x,
typename Field::Element &y) const
{
F.addin (x, y);
F.axpyin (y, _a, x);
return true;
}
}
#include "linbox/switch/cekstv-gf2.h"
#endif // __LINBOX_cekstv_H
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