Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / ga-0.10.0 / __ga_initial_population__.m

diff --git a/octave_packages/ga-0.10.0/__ga_initial_population__.m b/octave_packages/ga-0.10.0/__ga_initial_population__.m
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+## Copyright (C) 2008, 2010 Luca Favatella <slackydeb@gmail.com>
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 2 of the License, or
+## (at your option) any later version.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program; If not, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn{Function File} {@var{Population} =} __ga_initial_population__ (@var{GenomeLength}, @var{FitnessFcn}, @var{options})
+## Create an initial population.
+##
+## @seealso{__ga_problem__}
+## @end deftypefn
+
+## Author: Luca Favatella <slackydeb@gmail.com>
+## Version: 3.3
+
+                                #TODO consider PopulationSize as a
+                                #vector for multiple subpopolations
+
+function Population = \
+      __ga_initial_population__ (GenomeLength, FitnessFcn, options)
+  if (isempty (options.InitialPopulation))
+    Population(1:options.PopulationSize, 1:GenomeLength) = \
+        options.CreationFcn (GenomeLength, FitnessFcn, options);
+  else
+    if (columns (options.InitialPopulation) != GenomeLength) ## columns (InitialPopulation) > 0
+      error ("nonempty 'InitialPopulation' must have 'GenomeLength' columns");
+    else ## rows (InitialPopulation) > 0
+      nrIP = rows (options.InitialPopulation);
+      if (nrIP > options.PopulationSize)
+        error ("nonempty 'InitialPopulation' must have no more than \
+            'PopulationSize' rows");
+      elseif (nrIP == options.PopulationSize)
+        Population(1:options.PopulationSize, 1:GenomeLength) = \
+            options.InitialPopulation;
+      else # rows (InitialPopulation) < PopulationSize
+
+        ## create a complete new population, and then select only needed
+        ## individuals (creating only a partial population is difficult)
+        CreatedPopulation(1:options.PopulationSize, 1:GenomeLength) = \
+            options.CreationFcn (GenomeLength, FitnessFcn, options);
+        Population(1:options.PopulationSize, 1:GenomeLength) = vertcat \
+            (options.InitialPopulation(1:nrIP, 1:GenomeLength),
+             CreatedPopulation(1:(options.PopulationSize - nrIP),
+                               1:GenomeLength));
+      endif
+    endif
+  endif
+endfunction
+
+
+%!test
+%! GenomeLength = 2;
+%! options = gaoptimset ();
+%! Population = __ga_initial_population__ (GenomeLength, @rastriginsfcn, options);
+%! assert (size (Population), [options.PopulationSize, GenomeLength]);
+
+%!test
+%! GenomeLength = 2;
+%! options = gaoptimset ("InitialPopulation", [1, 2; 3, 4; 5, 6]);
+%! Population = __ga_initial_population__ (GenomeLength, @rastriginsfcn, options);
+%! assert (size (Population), [options.PopulationSize, GenomeLength]);
+
+
+## nonempty 'InitialPopulation' must have 'GenomeLength' columns
+
+%!error
+%! GenomeLength = 2;
+%! options = gaoptimset ("InitialPopulation", [1; 3; 5]);
+%! __ga_initial_population__ (GenomeLength, @rastriginsfcn, options);
+
+%!error
+%! GenomeLength = 2;
+%! options = gaoptimset ("InitialPopulation", [1, 1, 1; 3, 3, 3; 5, 5, 5]);
+%! __ga_initial_population__ (GenomeLength, @rastriginsfcn, options);
+
+
+## nonempty 'InitialPopulation' must have no more than 'PopulationSize' rows
+
+%!error
+%! GenomeLength = 2;
+%! options = gaoptimset ("InitialPopulation", [1, 2; 3, 4; 5, 6], "PopulationSize", 2);
+%! __ga_initial_population__ (GenomeLength, @rastriginsfcn, options);