initializega.m

遗传算法优化工具箱介绍及实例源程序,适合初学者用matlab进行遗传算法的学习

function [pop] = initializega(num, bounds, evalFN,evalOps,options)
% function [pop]=initializega(populationSize, variableBounds,evalFN,
%                           evalOps,options)
%    initializega creates a matrix of random numbers with 
%    a number of rows equal to the populationSize and a number
%    columns equal to the number of rows in bounds plus 1 for
%    the f(x) value which is found by applying the evalFN.
%    This is used by the ga to create the population if it
%    is not supplied.
%
% pop            - the initial, evaluated, random population 
% populatoinSize - the size of the population, i.e. the number to create
% variableBounds - a matrix which contains the bounds of each variable, i.e.
%                  [var1_high var1_low; var2_high var2_low; ....]
% evalFN         - the evaluation fn, usually the name of the .m file for 
%                  evaluation
% evalOps        - any options to be passed to the eval function defaults []
% options        - options to the initialize function, ie. 
%                  [type prec] where eps is the epsilon value 
%                  and the second option is 1 for float and 0 for binary, 
%                  prec is the precision of the variables defaults [1e-6 1]

% Binary and Real-Valued Simulation Evolution for Matlab GAOT V2 
% Copyright (C) 1998 C.R. Houck, J.A. Joines, M.G. Kay 
%
% C.R. Houck, J.Joines, and M.Kay. A genetic algorithm for function
% optimization: A Matlab implementation. ACM Transactions on Mathmatical
% Software, Submitted 1996.
%
% This program is free software; you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation; either version 1, or (at your option)
% any later version.
%
% This program 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 General Public License for more details. A copy of the GNU 
% General Public License can be obtained from the 
% Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

if nargin<5
  options=[1e-6 1];
end
if nargin<4
  evalOps=[];
end

if any(evalFN<48) %Not a .m file
  if options(2)==1 %Float GA
    estr=['x=pop(i,1); pop(i,xZomeLength)=', evalFN ';'];  
  else %Binary GA
    estr=['x=b2f(pop(i,:),bounds,bits); pop(i,xZomeLength)=', evalFN ';']; 
  end
else %A .m file
  if options(2)==1 %Float GA
    estr=['[ pop(i,:) pop(i,xZomeLength)]=' evalFN '(pop(i,:),[0 evalOps]);']; 
  else %Binary GA
    estr=['x=b2f(pop(i,:),bounds,bits);[x v]=' evalFN ...
	'(x,[0 evalOps]); pop(i,:)=[f2b(x,bounds,bits) v];'];  
    end
end


numVars     = size(bounds,1); 		%Number of variables
rng         = (bounds(:,2)-bounds(:,1))'; %The variable ranges'

if options(2)==1 %Float GA
  xZomeLength = numVars+1; 		%Length of string is numVar + fit
  pop         = zeros(num,xZomeLength); 	%Allocate the new population
  pop(:,1:numVars)=(ones(num,1)*rng).*(rand(num,numVars))+...
    (ones(num,1)*bounds(:,1)');
else %Binary GA
  bits=calcbits(bounds,options(1));
  xZomeLength = sum(bits)+1; 		%Length of string is numVar + fit
  pop = round(rand(num,sum(bits)+1));
end

for i=1:num
  eval(estr);
end