ref: a28fd682ca68f2267bbc670a0f998259bbd95476
dir: /FIR-POLY/demin.cc/
/*
** Copyright (C) 1998-2004 Erik de Castro Lopo <erikd@mega-nerd.com>
**
** The copyright above and this notice must be preserved in all
** copies of this source code. The copyright above does not
** evidence any actual or intended publication of this source code.
**
** This is unpublished proprietary trade secret of Erik de Castro
** Lopo. This source code may not be copied, disclosed,
** distributed, demonstrated or licensed except as authorized by
** Erik de Castro Lopo.
**
** No part of this program or publication may be reproduced,
** transmitted, transcribed, stored in a retrieval system,
** or translated into any language or computer language in any
** form or by any means, electronic, mechanical, magnetic,
** optical, chemical, manual, or otherwise, without the prior
** written permission of Erik de Castro Lopo.
*/
#include <stdio.h>
#include <unistd.h>
#include <Minimize.hh>
#include <PsuedoRand.hh>
class DEmin
{ private :
u_int PopSize, FuncCalcs, Generations ;
PsuedoRand Rand ;
GMatrix *MainVector, *Vector2 ;
double *MainCost, *Cost2 ;
double *ScaleFactor, *ScaleFactor2 ;
double *Crossover, *Crossover2 ;
MinFunc Function ;
public :
DEmin (void) ;
~DEmin (void) ;
void Setup (MinFunc func, const GMatrix& start, u_int popsize, double range, u_long seed) ;
GMatrix Minimize (double tol, u_int maxgen) ;
void PrintStats (void) ;
} ; // class DEmin
//======================================================================================
inline
void Swap (GMatrix **a, GMatrix **b)
{ GMatrix *temp ;
temp = *a ; *a = *b ; *b = temp ;
} ; //
inline void
Swap (double **a, double **b)
{ double *temp ;
temp = *a ; *a = *b ; *b = temp ;
} ; // Swap
inline double
Max (double a, double b)
{ return (a > b) ? a : b ;
} ; // Max
inline double
Min (double a, double b)
{ return (a < b) ? a : b ;
} ; // Max
//======================================================================================
double
MinDiffEvol (MinFunc Function, GMatrix& start, double Ftol, double range, u_long seedval)
{ DEmin *pfmin ;
u_int dimensions ;
dimensions = start.GetElements () ;
if (dimensions < 20)
dimensions = 20 ;
pfmin = new DEmin ;
pfmin -> Setup (Function, start, dimensions * 5, range, seedval) ;
Ftol = (Ftol < 1e-8) ? 1e-8 : Ftol ;
start = pfmin -> Minimize (Ftol, dimensions * 5000) ;
delete pfmin ;
return Function (start) ;
} ; // MinDiffEvol
//======================================================================================
DEmin::DEmin (void)
{ PopSize = 0 ;
FuncCalcs = 0 ;
Generations = 0 ;
MainVector = NULL ;
MainCost = NULL ;
ScaleFactor = NULL ;
Crossover = NULL ;
Vector2 = NULL ;
Cost2 = NULL ;
ScaleFactor2 = NULL ;
Crossover2 = NULL ;
} ; // DEmin constructor
DEmin::~DEmin (void)
{ if (PopSize)
{ delete [] MainVector ;
delete MainCost ;
delete ScaleFactor ;
delete Crossover ;
delete [] Vector2 ;
delete Cost2 ;
delete ScaleFactor2 ;
delete Crossover2 ;
} ;
PopSize = 0 ;
} ; // DEmin destructor
void
DEmin::Setup (MinFunc func, const GMatrix& start, u_int popsize, double range, u_long seed)
{ u_int k ;
u_short rows, cols ;
Generations = 0 ;
Function = func ;
PopSize = (popsize < 2) ? popsize + 2 : popsize ;
MainVector = new GMatrix [PopSize] ;
MainCost = new double [PopSize] ;
ScaleFactor = new double [PopSize] ;
Crossover = new double [PopSize] ;
Vector2 = new GMatrix [PopSize] ;
Cost2 = new double [PopSize] ;
ScaleFactor2 = new double [PopSize] ;
Crossover2 = new double [PopSize] ;
Rand.Seed (seed + 1234567) ;
rows = start.GetRows () ;
cols = start.GetCols () ;
GMatrix::PsuedoRandSeed (123123) ;
if (IsComplex (start))
for (k = 0 ; k < PopSize ; k++)
{ MainVector [k].SetSizeComplex (rows, cols) ;
MainVector [k].PsuedoRandomize () ;
MainVector [k] = (2.0 * range) * (MainVector [k] - Complex (0.5, 0.5)) ;
}
else
for (k = 0 ; k < PopSize ; k++)
{ MainVector [k].SetSizeDouble (rows, cols) ;
MainVector [k].PsuedoRandomize () ;
MainVector [k] = (2.0 * range) * (MainVector [k] - 0.5) ;
} ;
MainVector [0] = start ; // Must include given vector.
for (k = 0 ; k < PopSize ; k++)
{ MainCost [k] = Function (MainVector [k]) ;
FuncCalcs ++ ;
ScaleFactor [k] = 1.2 * Rand.UDDouble () ;
Crossover [k] = Rand.UDDouble () ;
} ;
return ;
} ; // DEmin::Setup
GMatrix
DEmin::Minimize (double Ftol, u_int maxgen)
{ u_int k, a, b, c ;
GMatrix temp ;
double scalefactor, crossover, cost, improvement, best ;
improvement = 100 * Ftol ;
best = 10e10 ;
while (Generations < maxgen && best > Ftol)
{ Swap (&MainVector, &Vector2) ;
Swap (&MainCost, &Cost2) ;
Swap (&ScaleFactor, &ScaleFactor2) ;
Swap (&Crossover, &Crossover2) ;
improvement = 0.0 ;
for (k = 0 ; k < PopSize ; k++)
{ do
a = u_int (double (PopSize) * Rand.UDDouble ()) ;
while (a == k || a >= PopSize) ;
do
b = u_int (double (PopSize) * Rand.UDDouble ()) ;
while (b == k || b == a || b >= PopSize) ;
do
c = u_int (double (PopSize) * Rand.UDDouble ()) ;
while (c == k || c == a || c == b || c >= PopSize) ;
if (a >= PopSize) { printf ("a - very bad (%u, %u).\n", a, PopSize) ; exit (0) ; } ;
if (b >= PopSize) { printf ("b - very bad (%u, %u).\n", b, PopSize) ; exit (0) ; } ;
if (c >= PopSize) { printf ("c - very bad (%u, %u).\n", c, PopSize) ; exit (0) ; } ;
scalefactor = 0.5 * (ScaleFactor2 [b] + ScaleFactor2 [c]) ;
temp = Vector2 [a] + scalefactor * (Vector2 [b] - Vector2 [c]) ;
crossover = 0.5 * (Crossover2 [k] + Crossover2 [a]) ;
temp.CrossOver (Vector2 [k], crossover) ;
cost = Function (temp) ;
FuncCalcs ++ ;
if (cost < Cost2 [k])
{ MainVector [k] = temp ;
MainCost [k] = cost ;
ScaleFactor [k] = scalefactor ;
Crossover [k] = crossover ;
improvement = 0.5 * (improvement + Max (improvement, Cost2 [k] - cost)) ;
best = Min (best, cost) ;
}
else
{ MainVector [k] = Vector2 [k] ;
MainCost [k] = Cost2 [k] ;
ScaleFactor [k] = ScaleFactor2 [k] ;
Crossover [k] = Crossover2 [k] ;
} ; // if
} ; // for k
Generations ++ ;
} ; // while
// Now find best vector.
for (a = 0, k = 1 ; k < PopSize ; k++)
if (MainCost [k] < MainCost [a])
a = k ;
temp = MainVector [a] ;
return temp ;
} ; // DEmin::Minimize
void
DEmin::PrintStats (void)
{ printf ("Generations : %8d\n", Generations) ;
printf ("Function evaluations : %8d\n", FuncCalcs) ;
putchar ('\n') ;
} ; // DEmin::PrintStats
//======================================================================================
// Do not edit or modify anything in this comment block.
// The arch-tag line is a file identity tag for the GNU Arch
// revision control system.
//
// arch-tag: e874ad11-7294-4757-9370-fd1e6e1261d0