The NEOS Server offers ASA (Adaptative Simulated Annealing) for the solution of simple bound constrained optimization problems in AMPL format.
Additionally other constraint types may also be added. For an unfeasible point the user defined objective function will return an invalid state, therefore a TOO_MANY_INVALID_STATES error may occur for problems where it is difficult to obtain feasible points.
ASA is a solver implemented by Lester Ingber.
The ASA AMPL interface was developed by Ismael Vaz in order to benchmark the PSwarm solver with a set of problems.
The interface is inspired in the ASAMIN MATLAB interface to ASA.
ASA makes no use of derivative information of the objective function (so modest problem size should be submitted).
For further information about ASA interface to AMPL,
contact aivaz@dps.uminho.pt.
For further information about ASA contact the ASA author.
Using the NEOS Server for ASA
AMPL input
The user may submit a model in
AMPL
format.
Examples of models in AMPL format can be found in the
PSwarm homepage.
The model is specified by a model file, and optionally,
a data file and a commands file.
If the command file is specified it must contain
the AMPL solve command.
The commands file can contain any AMPL command
or set
options for ASA with, for example,
option asa_options "maxf=1000";
Options include any of the parameters
 acceptance_frequency_modulus  Acceptance frequency modulus (integer)
 accepted_to_generated_ratio  Accepted to generated ratio (double)
 cost_parameter_scale  Cost parameter scale (double)
 cost_precision  Cost precision (double)
 delta_x  Delta x (double)
 generated_frequency_modulus  Generated frequency modulus (integer)
 include_integer_parameters  Include integer parameters (integer)
 initial_parameter_temperature  Initial parameters temperature (double)
 limit_acceptances  Limit acceptances (integer)
 limit_generated  Limit generated times problem dimension (integer)
 limit_invalid  Limit invalid (integer)
 maxf  Maximum number of function evaluations (integer)
 maximum_cost_repeat  Maximum cost repeat (integer)
 number_cost_samples  Number cost samples (integer)
 rand_seed  Ramdom seed (integer)
 reanneal_cost  Reanneal cost (integer)
 reanneal_parameters  Reanneal parameters (integer)
 sequential_parameters  Sequential parameters (integer)
 temperature_anneal_scale  Temperature anneal scale (double)
 temperature_ratio_scale  Temperature ratio scale (double)
 user_initial_parameters  User initial parameters (integer)
Printing directed to standard out is returned
to the user with the output.
