% CRTRP.M     (CReaTe an initial (Real-value) Population)
%
% This function creates a population of given size of random real-values. 
%
% Syntax:     Chrom = crtrp(Nind,FieldDR);
%
% Input parameters:
%   Nind     - A scalar containing the number of individuals in the new 
%           population.
%
%   FieldDR   - A matrix of size 2 by number of variables describing the
%           boundaries of each variable. It has the following structure:
%           [lower_bound;   (vector with lower bound for each veriable)
%           upper_bound]   (vector with upper bound for each veriable)
%           [lower_bound_var_1 lower_bound_var_2 ... lower_bound_var_Nvar;
%           upper_bound_var_1 upper_bound_var_2 ... upper_bound_var_Nvar]
%           example - each individuals consists of 4 variables:
%           FieldDR = [-100 -50 -30 -20;   % lower bound
%                   100 50 30 20]   % upper bound
%         
% Output parameter:
%   Chrom   - A matrix containing the random valued individuals of the
%           new population of size Nind by number of variables.

% Author:   Hartmut Pohlheim
% History:   23.11.93   file created
%         25.02.94   clean up, check parameter consistency


function Chrom = crtrp(Nind,FieldDR);

% Check parameter consistency
  [mN, nN] = size(Nind);
  [mF, Nvar] = size(FieldDR);
  if (nN+Nvar) < 2, error('parameter FieldDR missing'); end
  if (nN+Nvar) >= 2, end
  if (mN ~= 1 & nN ~= 1), error('Nind has to be a scalar'); end
  if mF ~= 2, error('FieldDR must be a matrix with 2 rows'); end

% Compute Matrix with Range of variables and Matrix with Lower value
  Range = rep((FieldDR(2,:)-FieldDR(1,:)),[Nind 1]);
  Lower = rep(FieldDR(1,:), [Nind 1]);

% Create initial population
% Each row contains one individual, the values of each variable uniformly
% distributed between lower and upper bound (given by FieldDR)
  Chrom = rand(Nind,Nvar) .* Range + Lower;


% End of function