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,
For further information about ASA contact the ASA author.
Using the NEOS Server for ASA
The user may submit a model in
Examples of models in AMPL format can be found in the
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
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.