setSeed

 - function for setting the seed for the random number generator

 copyright 2009-2012 Blair Armstrong, Christine Watson, David Plaut

    This file is part of SOS

    SOS is free software: you can redistribute it and/or modify
    it for academic and non-commercial purposes
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.  For commercial or for-profit
    uses, please contact the authors (sos@cnbc.cmu.edu).

    SOS 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.

0001 % - function for setting the seed for the random number generator
0002 %
0003 % copyright 2009-2012 Blair Armstrong, Christine Watson, David Plaut
0004 %
0005 %    This file is part of SOS
0006 %
0007 %    SOS is free software: you can redistribute it and/or modify
0008 %    it for academic and non-commercial purposes
0009 %    under the terms of the GNU General Public License as published by
0010 %    the Free Software Foundation, either version 3 of the License, or
0011 %    (at your option) any later version.  For commercial or for-profit
0012 %    uses, please contact the authors (sos@cnbc.cmu.edu).
0013 %
0014 %    SOS is distributed in the hope that it will be useful,
0015 %    but WITHOUT ANY WARRANTY; without even the implied warranty of
0016 %    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
0017 %    GNU General Public License for more details.
0018 
0019 %    You should have received a copy of the GNU General Public License
0020 %    along with SOS (see COPYING.txt).
0021 %    If not, see <http://www.gnu.org/licenses/>.
0022 
0023 
0024 function setSeed(seed)
0025     %% Sets the seed for the random number generator.
0026     % Useful for repeating the exact same optimization in the future, or to
0027     % force a different series of random numbers to be used in running the
0028     % same optimization.  Supply a positive number to set a fixed seed.
0029     %
0030     % Alternatively, supplying a negative number will set the generator to
0031     % a different random state on initialization, ensuring that a different
0032     % set of random states is generated.
0033     %
0034     %PARAMETERS:
0035     % seed - must be a positive number for that particular value to be used
0036     %       to seed the random generator.  Negative numbers set the random
0037     %       number generator to novel random states not linked to those
0038     %       numbers and can be used to forcibly generate different random
0039     %       sequences each time the algorithm is run.
0040     %
0041     
0042     p = inputParser;    
0043     p.addRequired('seed',@(seed)validateattributes(seed, {'numeric'}, ...
0044                 {'scalar', 'integer'}));
0045     p.parse(seed);
0046    
0047     if seed < 0
0048         verbosePrint('Seed < 0; setting to random value based on clock time',...
0049             'setSeed_set');       
0050         seed = sum(100*clock);
0051     else
0052         verbosePrint(['Setting seed to: ',num2str(seed)],...
0053             'setSeed_set');
0054     end
0055     
0056         rand('twister',seed);
0057 end