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 makes no use of derivative information of the objective function (so modest problem size should be submitted).

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.For further information about ASA interface to AMPL, contact aivaz@dps.uminho.pt. For further information about ASA contact the ASA author. Examples of models in AMPL format can be found in the PSwarm homepage.

The following is a list of options for ASA that the user may set via the
AMPL input files. For example, `option asa_options "maxf=1000";`

- 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)

The user must submit a model in AMPL format. Examples are provided in the examples section of the AMPL website.

The problem must be specified in a model file. A data file and commands
files may also be provided. If the commands file is specified, it must
contain the AMPL `solve`

command; however, it must not contain
the `model`

or `data`

commands. The model and data
files are renamed internally by NEOS.

The commands file may include option settings for the solver. To specify
solver options, add

option asa_options 'OPTIONS';where OPTIONS is a list of one or more of the available solver options for AMPL.

Web Submission Form

Enter the location of the ampl model (local file)

Enter the location of the ampl data file (local file)

Enter the location of the ampl commands file (local file)

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