objlinq.m

matlab的遗传算法的一个工具箱

% OBJLINQ.M      (OBJective function for LINear Quadratic problem)
%
% This function implements the discret LINEAR-QUADRATIC PROBLEM.
%
% Syntax:  ObjVal = objlinq(Chrom,switch_)
%
% Input parameters:
%    Chrom     - Matrix containing the chromosomes of the current
%                population. Each row corresponds to one individual's
%                string representation.
%                if Chrom == [], then special values will be returned
%    switch_    - if Chrom == [] and
%                switch_ == 1 (or []) return boundaries
%                switch_ == 2 return title
%                switch_ == 3 return value of global minimum
%
% Output parameters:
%    ObjVal    - Column vector containing the objective values of the
%                individuals in the current population.
%                if called with Chrom == [], then ObjVal contains
%                switch_ == 1, matrix with the boundaries of the function
%                switch_ == 2, text for the title of the graphic output
%                switch_ == 3, value of global minimum
%                

% Author:     Hartmut Pohlheim
% History:    18.02.94     file created (copy of valfun7.m)
%             01.03.94     name changed in obj*

function ObjVal = objlinq(Chrom,switch_);

% Dimension of objective function
   Dim = 45;

% values from MICHALEWICZ
   x0 = 100;              % start of X
   var = 1;               % 1 - 10 possible
   Para = [   1    1    1    1    1    16180.3399;
             10    1    1    1    1   109160.7978;
           1000    1    1    1    1 10009990.0200;
              1   10    1    1    1    37015.6212;
              1 1000    1    1    1   287569.3725;
              1    1    0    1    1    16180.3399;
              1    1 1000    1    1    16180.3399;
              1    1    1 0.01    1    10000.5000;
              1    1    1    1 0.01   431004.0987;
              1    1    1    1  100    10000.9999];
   s = Para(var,1); r = Para(var,2); q = Para(var,3);
   a = Para(var,4); b = Para(var,5); GlobalMinimum = Para(var,6);

% Compute population parameters
   [Nind,Nvar] = size(Chrom);

% Check size of Chrom and do the appropriate thing
   % if Chrom is [], then define size of boundary-matrix and values
   if Nind == 0
      % return text of title for graphic output
      if switch_ == 2
         ObjVal = ['Linear-quadratic problem (dis)-' int2str(Dim)];
      % return value of global minimum
      elseif switch_ == 3
         ObjVal = GlobalMinimum;
      % define size of boundary-matrix and values
      else   
         % lower and upper bound, identical for all n variables        
         ObjVal1 = [-100 -70 -50; 20 20 20];
         ObjVal = [ObjVal1 rep([-30;20],[1 Dim-3])];
      end
   % if Dim variables, compute values of function
   elseif Nvar == Dim
      ObjVal = zeros(Nind,1);
      X = zeros(Nind,Nvar+1);
      X(:,1) = rep(x0,[Nind 1]);
      for irun = 1:Nvar,
         X(:,irun+1) = a*X(:,irun) + b*Chrom(:,irun);
      end
      ObjVal = q * X(:,Nvar+1).^2 + sum((s * X(:,1:Nvar).^2 + r * Chrom.^2)')';
   % otherwise error, wrong format of Chrom
   else
      error('size of matrix Chrom is not correct for function evaluation');
   end   


% End of function