Documentation of objfun7

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Function Synopsis

ObjVal = objfun7(Chrom, option);

Help text

 OBJective function for schwefel's FUNction

 This function implements the SCHWEFEL function 7.

 Syntax:  ObjVal = objfun7(Chrom, option)

 Input parameters:
    Chrom     - Matrix containing the chromosomes of the current
                population. Each row corresponds to one individual's
                string representation.
                if Chrom == [], then speziell values will be returned
    option    - if Chrom == [] and
                option == 1 (or []) return boundaries
                option == 2 return title
                option == 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
                option == 1, matrix with the boundaries of the function
                option == 2, text for the title of the graphic output
                option == 3, value of global minimum
                
 See also: objfun1, objfun1a, objfun1b, objfun2, objfun6, objfun8, objfun9, objfun10

Cross-Reference Information

Listing of function objfun7

% Author:   Hartmut Pohlheim
% History:  27.11.1993  file created
%           30.11.1993  show Dim in figure titel
%           01.03.1994  name changed in obj*
%           17.02.1995  direct Dim removed and function cleaned
%           05.01.2004  function also works with 1 dimension (changed sum statement)


function ObjVal = objfun7(Chrom, option);

% 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
      % Default dimension of objective function
      Dim = 10;
      % return text of title for graphic output
      if option == 2
         ObjVal = ['SCHWEFELs function 7'];
      % return value of global minimum
      elseif option == 3
         xmin = 420.9687;
         ObjVal = Dim * (-xmin * sin(sqrt(abs(xmin))));
      % define size of boundary-matrix and values
      else   
         % lower and upper bound, identical for all n variables        
         ObjVal = repmat([-500; 500], [1 Dim]);
      end
   % compute values of function
   else
      % function 7, sum of -xi * sin(sqrt(abs(xi))) for i = 1:Nvar (Nvar = 10)
      % n = Nvar, -500 <= xi <= 500
      % global minimum at (xi) = (420.9687) ; fmin = -n * 420.9687
      ObjVal = sum((-Chrom .* sin(sqrt(abs(Chrom)))), 2);
   end   


% End of function