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tune_c.c
/* Copyright 2024, Gurobi Optimization, LLC */
/* This example reads a model from a file and tunes it.
It then writes the best parameter settings to a file
and solves the model using these parameters. */
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include "gurobi_c.h"
int
main(int argc,
char *argv[])
{
GRBenv *env = NULL;
GRBmodel *model = NULL;
int tuneresultcount;
int error = 0;
if (argc < 2) {
fprintf(stderr, "Usage: tune_c filename\n");
exit(1);
}
/* Create environment */
error = GRBloadenv(&env, "tune_c.log");
if (error) goto QUIT;
/* Read model from file */
error = GRBreadmodel(env, argv[1], &model);
if (error) goto QUIT;
/* Set the TuneResults parameter to 2
*
* The first parameter setting is the result for the first solved
* setting. The second entry the parameter setting of the best parameter
* setting.
*/
error = GRBsetintparam(GRBgetenv(model), GRB_INT_PAR_TUNERESULTS, 2);
if (error) goto QUIT;
/* Tune the model */
error = GRBtunemodel(model);
if (error) goto QUIT;
/* Get the number of tuning results */
error = GRBgetintattr(model, GRB_INT_ATTR_TUNE_RESULTCOUNT, &tuneresultcount);
if (error) goto QUIT;
if (tuneresultcount >= 2) {
/* Load the best tuned parameters into the model's environment
*
* Note, the first parameter setting is associated to the first solved
* setting and the second parameter setting to best tune result.
*/
error = GRBgettuneresult(model, 1);
if (error) goto QUIT;
/* Write tuned parameters to a file */
error = GRBwrite(model, "tune.prm");
if (error) goto QUIT;
/* Solve the model using the tuned parameters */
error = GRBoptimize(model);
if (error) goto QUIT;
}
QUIT:
/* Error reporting */
if (error) {
printf("ERROR: %s\n", GRBgeterrormsg(env));
exit(1);
}
/* Free model */
GRBfreemodel(model);
/* Free environment */
GRBfreeenv(env);
return 0;
}
