Add a useful package (from Source forge) for octave

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

diff --git a/octave_packages/ga-0.10.0/mutationgaussian.m b/octave_packages/ga-0.10.0/mutationgaussian.m
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+## Copyright (C) 2008 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/>.
+
+## Author: Luca Favatella <slackydeb@gmail.com>
+## Version: 1.7.1
+
+function mutationChildren = \
+      mutationgaussian (parents, options, nvars, FitnessFcn,
+                        state, thisScore,
+                        thisPopulation)
+  [LB(1, 1:nvars) UB(1, 1:nvars)] = \
+      __ga_popinitrange__ (options.PopInitRange, nvars);
+
+  ## start mutationgaussian logic
+  Scale = options.MutationFcn{1, 2};
+  #assert (size (Scale), [1 1]); ## DEBUG
+  Shrink = options.MutationFcn{1, 3};
+  #assert (size (Shrink), [1 1]); ## DEBUG
+
+  ## initial standard deviation (i.e. when state.Generation == 0)
+  tmp_std = Scale * (UB - LB); ## vector = scalar * vector
+
+  ## recursively compute current standard deviation
+  for k = 1:state.Generation
+    tmp_std(1, 1:nvars) = (1 - Shrink * (k / options.Generations)) * tmp_std;
+  endfor
+  current_std(1, 1:nvars) = tmp_std;
+  nc_parents = columns (parents);
+  expanded_current_std(1:nc_parents, 1:nvars) = \
+      ones (nc_parents, 1) * current_std;
+
+  ## finally add random numbers
+  mutationChildren(1:nc_parents, 1:nvars) = \
+      thisPopulation(parents(1, 1:nc_parents), 1:nvars) + \
+      expanded_current_std .* randn (nc_parents, nvars);
+endfunction
+
+
+## number of input arguments
+# TODO
+
+## number of output arguments
+# TODO
+
+## type of arguments
+# TODO
+
+# TODO