changelog.txt

Aug 6, 2009
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v1  - Objective functions are now allowed to have any 
      2-dimensional input shape; all functions must be able 
      to evaluate arrays of the same size and shape as [lb]
      or [ub].
    - added exitflag (-3) in case no solution is found 
      (all values INF/NaN). 
    - Removed parameters [k] and [minT] from ASA algorithm. 
      They are not mentioned in any papers, and testing 
      indicated they are indeed superfluous. Also, T0 can
      now be left empty, in which case an optimal initial
      temperature is estimated
    - Corrected small mistake in argument [which_ones] - it
      HAD to be a cell-array, which is confusing if only 1
      algorithm is used ( {'GA'} in stead of simply 'GA'). 
    - Improved randomization of number of iterations to 
      make and population size to use (break_values 
      previously had a much larger probability to have its
      first value the largest).
    - the [MinDescent] and [MinDescentMultiplier] have been 
      replaced by the MATLAB-style [TolIters], [TolX], and 
      [TolFun] options. 
    - Error handling has improved.  
    - Added option 'ReHeating'; this is the re-heating 
      constant used after an interchange operation, in ASA 
      populations.
    - Added another algorithm: MultiStart (MS). This is the
      simplest of them all; it's just FMINSEARCH, started at
      randomly generated starting values. for now, when 
      using MS, no display options can be used; this is 
      something for a later release, as it is much more
      complicated to display its progress in the current 
      context. It is therefore NOT used by default. 
    - I made some *severe* mistakes in the implementation of 
      the different algorithms:
           * GA:  - Added tournament selection for GA in 
                    single objective. previously, parents 
                    were simply selected at random, which 
                    meant that their fitness value would 
                    not increase their chances of 
                    reproduction at all.
                  - Real representation was 'unstringed'; 
                    only the descision variables themselves
                    were crossed-over and mutated, NOT the
                    individual digits as is required. The
                    problem is corrected now, but at a cost:
                    INT2STR() is rather slow...
           * PSO: - The social network topology was 
                    essentially random. This already was a
                    TODO-item previously, but now it's done
                    :) I added a new option for PSO: 
                    OPTIONS.NetworkTopology. This options 
                    can assume the values 'star', 'ring' or
                    'fully_connected'.
                  - Updating the neighborhood bests was 
                    horrendously slow (and buggy; only the              
                    first few neighbors ever got selected).             
                    I got rid of the loop and vectorized the 
                    replacement, so its fast now (and 
                    correct :). 
            * SA: - Creating new individuals was done with
                    only one dimension at a time, and with a
                    simple RANDN(). Now, new individuals are 
                    creating using a standard Bolzmann 
                    generating scheme (sqrt(T)*randn()). 


Jul 24, 2009
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v0  - first release.