Documentation of recdis

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Function Synopsis

NewChrom = recdis(OldChrom, RecRate);

Help text

 RECombination DIScrete

 This function performs discrete recombination between pairs of individuals
 and returns the new individuals after mating.

 Syntax:  NewChrom = recdis(OldChrom, RecRate)

 Input parameters:
    OldChrom  - Matrix containing the chromosomes of the old
                population. Each row corresponds to one individual
                (in any form, not necessarily real values).
    RecRate   - Probability of recombination ocurring between pairs
                of individuals. (not used, only for compatibility)

 Output parameter:
    NewChrom  - Matrix containing the chromosomes of the population
                after mating, ready to be mutated and/or evaluated,
                in the same format as OldChrom.

 See also: recombin, recint, reclin, recmut, recsp, recdp, recsh

Cross-Reference Information

Listing of function recdis

%  Author:    Hartmut Pohlheim
%  History:   23.11.94     file created
%             24.11.94     style improved
%             06.12.94     change of name of function
%             25.02.95     clean up
%             19.03.95     multipopulation support removed


function NewChrom = recdis(OldChrom, RecRate);

% Identify the population size (Nind) and the number of variables (Nvar)
   [Nind,Nvar] = size(OldChrom);

% Identify the number of matings
   Xops = floor(Nind/2);

% which parent gives the value
   Mask1 = (rand(Xops, Nvar) < 0.5);
   Mask2 = (rand(Xops, Nvar) < 0.5);

% Performs recombination
   odd = 1:2:Nind-1;
   even= 2:2:Nind;
   NewChrom(odd,:)  = (OldChrom(odd,:).* Mask1) + (OldChrom(even,:) .* (~Mask1));
   NewChrom(even,:) = (OldChrom(odd,:).* Mask2) + (OldChrom(even,:) .* (~Mask2));

% If the number of individuals is odd, the last individual cannot be mated
% but must be included in the new population
   if rem(Nind,2),  NewChrom(Nind,:) = OldChrom(Nind,:); end


% End of function