www.pudn.com > geneticbs2rv.rar > MUT.M

% MUT.m 
% 
% This function takes the representation of the current population, 
% mutates each element with given probability and returns the resulting 
% population. 
% 
% Syntax:	NewChrom = mut(OldChrom,Pm,BaseV) 
% 
% Input parameters: 
% 
%		OldChrom - A matrix containing the chromosomes of the 
%			   current population. Each row corresponds to 
%			   an individuals string representation. 
% 
%		Pm	 - Mutation probability (scalar). Default value 
%			   of Pm = 0.7/Lind, where Lind is the chromosome 
%			   length is assumed if omitted. 
% 
%		BaseV	 - Optional row vector of the same length as the 
%			   chromosome structure defining the base of the  
%			   individual elements of the chromosome. Binary 
%			   representation is assumed if omitted. 
% 
% Output parameter: 
% 
%		NewChrom - A Matrix containing a mutated version of 
%			   OldChrom. 
% 
 
% Author: Andrew Chipperfield 
% Date: 25-Jan-94 
 
function NewChrom = mut(OldChrom,Pm,BaseV) 
 
% get population size (Nind) and chromosome length (Lind) 
[Nind, Lind] = size(OldChrom) ; 
 
% check input parameters 
if nargin < 2, Pm = 0.7/Lind ; end 
if isnan(Pm), Pm = 0.7/Lind; end 
 
if (nargin < 3), BaseV = crtbase(Lind);  end 
if (isnan(BaseV)), BaseV = crtbase(Lind);  end 
if (isempty(BaseV)), BaseV = crtbase(Lind);  end 
 
if (nargin == 3) & (Lind ~= length(BaseV)) 
   error('OldChrom and BaseV are incompatible'), end 
 
% create mutation mask matrix 
BaseM = BaseV(ones(Nind,1),:) ; 
 
% perform mutation on chromosome structure 
NewChrom = rem(OldChrom+(rand(Nind,Lind)