/*------------------------------------------------------------------------*/
/* File: examples/src/diet.c */
/* Version 8.1 */
/*------------------------------------------------------------------------*/
/* Copyright (C) 1997-2002 by ILOG. */
/* All Rights Reserved. */
/* Permission is expressly granted to use this example in the */
/* course of developing applications that use ILOG products. */
/*------------------------------------------------------------------------*/
/* diet.c - reading data for a dietary problem, building the model
and solving it. methods for creating the model:
diet -r <datafile> generates the problem by adding rows
diet -c <datafile> generates the problem by adding columns
*/
/* Bring in the CPLEX function declarations and the C library
header file stdio.h with the following single include. */
#include <ilcplex/cplex.h>
/* Bring in the declarations for the string functions */
#include <stdlib.h>
#include <string.h>
/* Include declaration for functions at end of program */
static int
readarray (FILE *in, int *num_p, double **data_p),
readdata (char* file,
int *nfoods_p, double **cost_p,
double **lb_p, double **ub_p,
int *nnutr_p, double **nutrmin_p, double **nutrmax_p,
double ***nutrper_p),
populatebyrow (CPXENVptr env, CPXLPptr lp,
int nfoods, double *cost, double *lb, double *ub,
int nnutr, double *nutrmin, double *nutrmax,
double **nutrper),
populatebycolumn (CPXENVptr env, CPXLPptr lp,
int nfoods, double *cost, double *lb, double *ub,
int nnutr, double *nutrmin, double *nutrmax,
double **nutrper);
static void
free_and_null (char **ptr),
usage (char *progname);
int
main (int argc, char **argv)
{
int status = 0;
int nfoods;
int nnutr;
double *cost = NULL;
double *lb = NULL;
double *ub = NULL;
double *nutrmin = NULL;
double *nutrmax = NULL;
double **nutrper = NULL;
double *x = NULL;
double objval;
int solstat;
/* Declare and allocate space for the variables and arrays where we
will store the optimization results including the status, objective
value, variable values, dual values, row slacks and variable
reduced costs. */
CPXENVptr env = NULL;
CPXLPptr lp = NULL;
int i, j;
/* Check the command line arguments */
if (( argc != 3 ) ||
( argv[1][0] != '-' ) ||
( strchr ("rc", argv[1][1]) == NULL ) ) {
usage (argv[0]);
goto TERMINATE;
}
status = readdata(argv[2], &nfoods, &cost, &lb, &ub,
&nnutr, &nutrmin, &nutrmax, &nutrper);
if ( status ) goto TERMINATE;
/* Initialize the CPLEX environment */
env = CPXopenCPLEX (&status);
/* If an error occurs, the status value indicates the reason for
failure. A call to CPXgeterrorstring will produce the text of
the error message. Note that CPXopenCPLEX produces no output,
so the only way to see the cause of the error is to use
CPXgeterrorstring. For other CPLEX routines, the errors will
be seen if the CPX_PARAM_SCRIND indicator is set to CPX_ON. */
if ( env == NULL ) {
char errmsg[1024];
fprintf (stderr, "Could not open CPLEX environment.\n");
CPXgeterrorstring (env, status, errmsg);
fprintf (stderr, "%s", errmsg);
goto TERMINATE;
}
/* Turn on output to the screen */
status = CPXsetintparam (env, CPX_PARAM_SCRIND, CPX_ON);
if ( status ) {
fprintf (stderr,
"Failure to turn on screen indicator, error %d.\n", status);
goto TERMINATE;
}
/* Turn on data checking */
status = CPXsetintparam (env, CPX_PARAM_DATACHECK, CPX_ON);
if ( status ) {
fprintf (stderr,
"Failure to turn on data checking, error %d.\n", status);
goto TERMINATE;
}
/* Create the problem. */
lp = CPXcreateprob (env, &status, "diet");
/* A returned pointer of NULL may mean that not enough memory
was available or there was some other problem. In the case of
failure, an error message will have been written to the error
channel from inside CPLEX. In this example, the setting of
the parameter CPX_PARAM_SCRIND causes the error message to
appear on stdout. */
if ( lp == NULL ) {
fprintf (stderr, "Failed to create LP.\n");
goto TERMINATE;
}
/* Now populate the problem with the data. For building large
problems, consider setting the row, column and nonzero growth
parameters before performing this task. */
switch (argv[1][1]) {
case 'r':
status = populatebyrow (env, lp, nfoods, cost, lb, ub,
nnutr, nutrmin, nutrmax, nutrper);
break;
case 'c':
status = populatebycolumn (env, lp, nfoods, cost, lb, ub,
nnutr, nutrmin, nutrmax, nutrper);
break;
}
if ( status ) {
fprintf (stderr, "Failed to populate problem.\n");
goto TERMINATE;
}
/* Optimize the problem and obtain solution. */
status = CPXlpopt (env, lp);
if ( status ) {
fprintf (stderr, "Failed to optimize LP.\n");
goto TERMINATE;
}
x = (double *) malloc (nfoods * sizeof(double));
if ( x == NULL ) {
status = CPXERR_NO_MEMORY;
fprintf (stderr, "Could not allocate memory for solution.\n");
goto TERMINATE;
}
status = CPXsolution (env, lp, &solstat, &objval, x, NULL, NULL, NULL);
if ( status ) {
fprintf (stderr, "Failed to obtain solution.\n");
goto TERMINATE;
}
/* Write the output to the screen. */
printf ("\nSolution status = %d\n", solstat);
printf ("Solution value = %f\n\n", objval);
for (j = 0; j < nfoods; j++) {
printf ("Food %d: Buy = %10f\n", j, x[j]);
}
/* Finally, write a copy of the problem to a file. */
status = CPXwriteprob (env, lp, "diet.lp", NULL);
if ( status ) {
fprintf (stderr, "Failed to write LP to disk.\n");
goto TERMINATE;
}
TERMINATE:
/* Free up the problem as allocated by CPXcreateprob, if necessary */
if ( lp != NULL ) {
status = CPXfreeprob (env, &lp);
if ( status ) {
fprintf (stderr, "CPXfreeprob failed, error code %d.\n", status);
}
}
/* Free up the CPLEX environment, if necessary */
if ( env != NULL ) {
status = CPXcloseCPLEX (&env);
/* Note that CPXcloseCPLEX produces no output,
so the only way to see the cause of the error is to use
CPXgeterrorstring. For other CPLEX routines, the errors will
be seen if the CPX_PARAM_SCRIND indicator is set to CPX_ON. */
if ( status > 0 ) {
char errmsg[1024];
fprintf (stderr, "Could not close CPLEX environment.\n");
CPXgeterrorstring (env, status, errmsg);
fprintf (stderr, "%s", errmsg);
}
}
if ( nutrper != NULL ) {
for (i = 0; i < nnutr; ++i) {
free_and_null ((char **) &(nutrper[i]));
}
}
free_and_null ((char **) &nutrper);
free_and_null ((char **) &cost);
free_and_null ((char **) &cost);
free_and_null ((char **) &lb);
free_and_null ((char **) &ub);
free_and_null ((char **) &nutrmin);
free_and_null ((char **) &nutrmax);
free_and_null ((char **) &x);
return (status);
} /* END main */
static int
populatebyrow (CPXENVptr env, CPXLPptr lp,
int nfoods, double *cost, double *lb, double *ub,
int nnutr, double *nutrmin, double *nutrmax,
double **nutrper)
{
int status = 0;
int zero = 0;
int *ind = NULL;
int i, j;
ind = (int*) malloc(nfoods * sizeof(int));
if ( ind == NULL ) {
status = CPXERR_NO_MEMORY;
goto TERMINATE;
}
for (j = 0; j < nfoods; j++) {
ind[j] = j;
}
status = CPXnewcols (env, lp, nfoods, cost, lb, ub, NULL, NULL);
if ( status ) goto TERMINATE;
for (i = 0; i < nnutr; i++) {
double rng = nutrmax[i] - nutrmin[i];
status = CPXaddrows (env, lp, 0, 1, nfoods, nutrmin+i, "R",
&zero, ind, nutrper[i], NULL, NULL);
if ( status ) goto TERMINATE;
status = CPXchgrngval (env, lp, 1, &i, &rng);
if ( status ) goto TERMINATE;
}
TERMINATE:
free_and_null ((char **)&ind);
return (status);
} /* END populatebyrow */
* To populate by column, we first create the rows, and then add the
columns. */
static int
populatebycolumn (CPXENVptr env, CPXLPptr lp,
int nfoods, double *cost, double *lb, double *ub,
int nnutr, double *nutrmin, double *nutrmax,
double **nutrper)
{
int status = 0;
int i, j;
int zero = 0;
int *ind = NULL;
double *val = NULL;
char *sense = NULL;
double *rngval = NULL;
sense = (char*)malloc(nnutr * sizeof(char));
if ( sense == NULL ) {
status = CPXERR_NO_MEMORY;
goto TERMINATE;
}
for (i = 0; i < nnutr; i++) {
sense[i] = 'R';
}
val = (double*)malloc(nnutr * sizeof(double));
if ( val == NULL ) {
status = CPXERR_NO_MEMORY;
goto TERMINATE;
}
rngval = (double*)malloc(nnutr * sizeof(double));
if ( rngval == NULL ) {
status = CPXERR_NO_MEMORY;
goto TERMINATE;
}
for (i = 0; i < nnutr; i++) {
rngval[i] = nutrmax[i] - nutrmin[i];
}
ind = (int*) malloc(nfoods * sizeof(int));
if ( ind == NULL ) {
status = CPXERR_NO_MEMORY;
goto TERMINATE;
}
for (i = 0; i < nnutr; i++) {
ind[i] = i;
}
status = CPXnewrows (env, lp, nnutr, nutrmin, sense, rngval, NULL);
if ( status ) goto TERMINATE;
for (j = 0; j < nfoods; ++j) {
for (i = 0; i < nnutr; i++) {
val[i] = nutrper[i][j];
}
status = CPXaddcols (env, lp, 1, nnutr, cost+j, &zero,
ind, val, lb+j, ub+j, NULL);
if ( status ) goto TERMINATE;
}
TERMINATE:
free_and_null ((char **)&sense);
free_and_null ((char **)&rngval);
free_and_null ((char **)&ind);
free_and_null ((char **)&val);
return (status);
} /* END populatebycolumn */
/* This simple routine frees up the pointer *ptr, and sets *ptr to NULL */
static void
free_and_null (char **ptr)
{
if ( *ptr != NULL ) {
free (*ptr);
*ptr = NULL;
}
} /* END free_and_null */
static void
usage (char *progname)
{
fprintf (stderr,"Usage: %s -X <datafile>\n", progname);
fprintf (stderr," where X is one of the following options: \n");
fprintf (stderr," r generate problem by row\n");
fprintf (stderr," c generate problem by column\n");
fprintf (stderr," Exiting...\n");
} /* END usage */
static int
readarray (FILE *in, int *num_p, double **data_p)
{
int status = 0;
int max, num;
char ch;
num = 0;
max = 10;
*data_p = (double*)malloc(max * sizeof(double));
if ( *data_p == NULL ) {
status = CPXERR_NO_MEMORY;
goto TERMINATE;
}
for (;;) {
fscanf (in, "%c", &ch);
if ( ch == '\t' ||
ch == '\r' ||
ch == ' ' ||
ch == '\n' ) continue;
if ( ch == '[' ) break;
status = -1;
goto TERMINATE;
}
for(;;) {
int read;
read = fscanf (in, "%lg", (*data_p)+num);
if ( read == 0 ) {
status = -1;
goto TERMINATE;
}
num++;
if ( num >= max ) {
max *= 2;
*data_p = (double*)realloc(*data_p, max * sizeof(double));
if ( *data_p == NULL ) {
status = CPXERR_NO_MEMORY;
goto TERMINATE;
}
}
do {
fscanf (in, "%c", &ch);
} while (ch == ' ' || ch == '\n' || ch == '\t' || ch == '\r');
if ( ch == ']' ) break;
else if ( ch != ',' ) {
status = -1;
goto TERMINATE;
}
}
*num_p = num;
TERMINATE:
return (status);
} /* END readarray */
static int
readdata (char* file,
int *nfoods_p, double **cost_p, double **lb_p, double **ub_p,
int *nnutr_p, double **nutrmin_p, double **nutrmax_p,
double ***nutrper_p)
{
int status = 0;
int ncost, nlb, nub;
int nmin, nmax;
int i, n;
char ch;
FILE *in = NULL;
in = fopen(file, "r");
if ( in == NULL ) {
status = -1;
goto TERMINATE;
}
if ( (status = readarray(in, &ncost, cost_p)) ) goto TERMINATE;
if ( (status = readarray(in, &nlb, lb_p)) ) goto TERMINATE;
if ( (status = readarray(in, &nub, ub_p)) ) goto TERMINATE;
if ( ncost != nlb || ncost != nub ) {
status = -1;
goto TERMINATE;
}
*nfoods_p = ncost;
if ( (status = readarray(in, &nmin, nutrmin_p)) ) goto TERMINATE;
if ( (status = readarray(in, &nmax, nutrmax_p)) ) goto TERMINATE;
if ( nmax != nmin ) {
status = -1;
goto TERMINATE;
}
*nnutr_p = nmin;
*nutrper_p = (double**)malloc(nmin * sizeof(double*));
if ( *nutrper_p == NULL ) {
status = CPXERR_NO_MEMORY;
goto TERMINATE;
}
for (;;) {
fscanf (in, "%c", &ch);
if ( ch == '\t' ||
ch == '\r' ||
ch == ' ' ||
ch == '\n' ) continue;
if ( ch == '[' ) break;
status = -1;
goto TERMINATE;
}
for ( i = 0; i < nmin; i++ ) {
if ( (status = readarray(in, &n, (*nutrper_p)+i)) ) goto TERMINATE;
if ( n != ncost ) {
status = -1;
goto TERMINATE;
}
fscanf (in, "%c", &ch);
if ( i < nmin-1 && ch != ',' ) {
status = -1;
goto TERMINATE;
}
}
if ( ch != ']' ) {
status = -1;
goto TERMINATE;
}
TERMINATE:
return (status);
} /* END readdata */
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