AMPL: A Modeling Language for Mathematical Programming

PATH Directives for AMPL

To set these directives, assign a string specifying their values to the AMPL option path_options. For example:
     ampl: option path_options 'restart_limit=1 logfile=log.tmp crash_method=none';

Option Default Explanation
convergence_tolerance 1e-6 Stopping criterion
crash_iteration_limit 50 Maximum iterations allowed in crash
crash_method pnewton pnewton or none
crash_minimum_dimension 1 Minimum problem dimension required to perform crash
crash_nbchange_limit 1 Number of changes to the basis allowed
cumulative_iteration_limit 10000 Maximum minor iterations allowed
lemke_start automatic Frequency of lemke starts (automatic, first, always)
major_iteration_limit 500 Maximum major iterations allowed
minor_iteration_limit 1000 Maximum minor iterations allowed in each major iteration
nms yes Allow searching, watchdoging, and non-monotone descent
nms_initial_reference_factor 20 Controls size of initial reference value
nms_memory_size 10 Number of reference values kept
nms_mstep_frequency 10 Frequency at which m steps are performed
nms_searchtype path path or line
output yes Turn output on or off. If output is turned off, selected parts can be turned back on.
output_crash_iterations yes Output information on crash iterations
output_crash_iterations_frequency 1 Frequency at which crash iteration log is printed
output_errors yes Output error messages
output_linear_model no Output linear model each major iteration
output_major_iterations yes Output information on major iterations
output_major_iterations_frequency 1 Frequency at which major iteration log is printed
output_minor_iterations yes Output information on minor iterations
output_minor_iterations_frequency 500 Frequency at which minor iteration log is printed
output_options no Output all options and their values
output_warnings no Output warning messages
proximal_perturbation 0.0 Initial perturbation
restart_limit 3 Maximum number of restarts (0 - 3)
time_limit 3600 Maximum number of seconds algorithm is allowed to run

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