www.pudn.com > geneticbs2rv.rar > BS2RV.M

% BS2RV.m - Binary string to real vector 
% 
% This function decodes binary chromosomes into vectors of reals. The 
% chromosomes are seen as the concatenation of binary strings of given 
% length, and decoded into real numbers in a specified interval using 
% either standard binary or Gray decoding. 
% 
% Syntax:       Phen = bs2rv(Chrom,FieldD) 
% 
% Input parameters: 
% 
%               Chrom    - Matrix containing the chromosomes of the current 
%                          population. Each line corresponds to one 
%                          individual's concatenated binary string 
%			   representation. Leftmost bits are MSb and 
%			   rightmost are LSb. 
% 
%               FieldD   - Matrix describing the length and how to decode 
%			   each substring in the chromosome. It has the 
%			   following structure: 
% 
%				[len;		(num) 
%				 lb;		(num) 
%				 ub;		(num) 
%				 code;		(0=binary     | 1=gray) 
%				 scale;		(0=arithmetic | 1=logarithmic) 
%				 lbin;		(0=excluded   | 1=included) 
%				 ubin];		(0=excluded   | 1=included) 
% 
%			   where 
%				len   - row vector containing the length of 
%					each substring in Chrom. sum(len) 
%					should equal the individual length. 
%				lb, 
%				ub    - Lower and upper bounds for each 
%					variable.  
%				code  - binary row vector indicating how each 
%					substring is to be decoded. 
%				scale - binary row vector indicating where to 
%					use arithmetic and/or logarithmic 
%					scaling. 
%				lbin, 
%				ubin  - binary row vectors indicating whether 
%					or not to include each bound in the 
%					representation range 
% 
% Output parameter: 
% 
%               Phen     - Real matrix containing the population phenotypes. 
 
% 
% Author: Carlos Fonseca, 	Updated: Andrew Chipperfield 
% Date: 08/06/93,		Date: 26-Jan-94 
 
function Phen = bs2rv(Chrom,FieldD) 
 
% Identify the population size (Nind) 
%      and the chromosome length (Lind) 
[Nind,Lind] = size(Chrom); 
 
% Identify the number of decision variables (Nvar) 
[seven,Nvar] = size(FieldD); 
 
if seven ~= 7 
	error('FieldD must have 7 rows.'); 
end 
 
% Get substring properties 
len = FieldD(1,:); 
lb = FieldD(2,:); 
ub = FieldD(3,:); 
code = ~(~FieldD(4,:)); 
scale = ~(~FieldD(5,:)); 
lin = ~(~FieldD(6,:)); 
uin = ~(~FieldD(7,:)); 
 
% Check substring properties for consistency 
if sum(len) ~= Lind, 
	error('Data in FieldD must agree with chromosome length'); 
end 
 
if ~all(lb(scale).*ub(scale)>0) 
	error('Log-scaled variables must not include 0 in their range'); 
end 
 
% Decode chromosomes 
Phen = zeros(Nind,Nvar); 
 
lf = cumsum(len); 
li = cumsum([1 len]); 
Prec = .5 .^ len; 
 
logsgn = sign(lb(scale)); 
lb(scale) = log( abs(lb(scale)) ); 
ub(scale) = log( abs(ub(scale)) ); 
delta = ub - lb; 
 
Prec = .5 .^ len; 
num = (~lin) .* Prec; 
den = (lin + uin - 1) .* Prec; 
 
for i = 1:Nvar, 
    idx = li(i):lf(i); 
    if code(i) % Gray decoding 
	    Chrom(:,idx)=rem(cumsum(Chrom(:,idx)')',2); 
    end 
    Phen(:,i) = Chrom(:,idx) * [ (.5).^(1:len(i))' ]; 
    Phen(:,i) = lb(i) + delta(i) * (Phen(:,i) + num(i)) ./ (1 - den(i)); 
end 
 
expand = ones(Nind,1); 
if any(scale) 
	Phen(:,scale) = logsgn(expand,:) .* exp(Phen(:,scale)); 
end