AMPL: A Modeling Language for Mathematical Programming

Gecode Directives for AMPL

To set these directives, assign a string specifying their values to the AMPL option gecode_options. For example:
     ampl: option gecode_options 'version nodelimit=30000 val_branching=min';


a_d            
      Adaptive recomputation distance.

c_d            
      Commit recomputation distance.

faillimit      
      Fail limit.

memorylimit    
      Memory limit.

nodelimit      
      Node limit.

outfreq        
      Output log frequency in seconds.  The value should be a positive integer.

outlev         
      0 or 1 (default 0):  Whether to print solution log.

threads        
      The number of parallel threads to use.  Assume that your computer
      has m processing units and that the value for threads is n.
          * If n = 0, then m threads are used (as many as available
            processing units).
          * If n >= 1, then n threads are used (absolute number of
            threads to be used).
          * If n <= -1, then m + n threads are used (absolute number
            of processing units not to be used). For example, when
            n = -6 and m = 8, then 2 threads are used.
          * If 0 < n < 1, then n * m threads are used (relative number
            of processing units to be used). For example, when n = 0.5
            and m = 8, then 4 threads are used.
          * If -1 < n < 0, then (1 + n) * m threads are used (relative
            number of processing units not to be used). For example,
            when n = -0.25 and m = 8, then 6 threads are used.
      All values are rounded and at least one thread is used.

timelimit      
      Time limit.

val_branching  
      Value branching.  Possible values:
            min        - smallest value (default)
            med        - greatest value not greater than the median
            max        - largest value
            rnd        - random value
            split_min  - values not greater than mean of smallest and
                         largest value
            split_max  - values greater than mean of smallest and largest
                         value
            range_min  - values from smallest range, if domain has several
                         ranges; otherwise, values not greater than mean of
                         smallest and largest value
            range_max  - values from largest range, if domain has several
                         ranges; otherwise, values greater than mean of
                         smallest and largest value
            values_min - all values starting from smallest
            values_min - all values starting from largest

var_branching  
      Variable branching.  Possible values:
            none            - first unassigned
            rnd             - random
            degree_min      - smallest degree
            degree_max      - largest degree
            afc_min         - smallest accumulated failure count (AFC)
            afc_max         - largest accumulated failure count (AFC)
            min_min         - smallest minimum value
            min_max         - largest minimum value
            max_min         - smallest maximum value
            max_max         - largest maximum value
            size_min        - smallest domain size (default)
            size_max        - largest domain size
            size_degree_min - smallest domain size divided by degree
            size_degree_max - largest domain size divided by degree
            size_afc_min    - smallest domain size divided by AFC
            size_afc_max    - largest domain size divided by AFC
            regret_min_min  - smallest minimum-regret
            regret_min_max  - largest minimum-regret
            regret_max_min  - smallest maximum-regret
            regret_max_max  - largest maximum-regret

version        
      Single-word phrase: report version details before solving the problem.

wantsol        
      In a stand-alone invocation (no -AMPL on the command line), what
      solution information to write.  Sum of
            1 = write .sol file
            2 = primal variables to stdout
            4 = dual variables to stdout
            8 = suppress solution message


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LAST MODIFIED 28 FEBRUARY 2013 BY 4er.