/******************************************************** BCL Example Problems ==================== file xbdlvriis2rep.c ```````````````````` Transportation problem (infeasible data). Repairing infeasibility. - Using Optimizer functions - (c) 2008 Fair Isaac Corporation author: S.Heipcke, Jan. 2008, rev. Mar. 2011 ********************************************************/ #include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "xprb.h"
#include "xprs.h"

#define NSupp 10                        /* Number of suppliers */
#define NCust 7                         /* Number of customers */
#define MaxArcs 100                     /* Max. num. of non-zero cost values */

#define VANFILE XPRBDATAPATH "/delivery/ifvan.dat"    /* Van data file */
#define COSTFILE XPRBDATAPATH "/delivery/cost.dat"    /* Cost data file */

void printsolution(XPRBprob prob, int scode, XPRBvar x[][NCust]);
void printsolution2(XPRSprob op, int scode, XPRBvar x[][NCust]);

/****DATA****/
/* Supplier:      London  Luton  B'ham Bristl  Derby Stckpt   York */
double SUPPLY[] = {140.0, 200.0,  50.0,  10.0, 400.0, 200.0,  20.0,
/* Supplier: Derby  Soton Scnthp */
             90.0,  30.0,  12};
/* Customer:       London Livpol Doncst   York   Hull  Manchr Shffld */
double DEMAND[] = {1230.3, 560.4, 117.1, 592.8, 310.0, 1247.0,  86};

double COST[NSupp][NCust];        /* Cost per supplier-customer pair */

double IFVAN[NSupp][NCust];       /* Non-zero if route uses vans instead
                                     of lorries */
double VANCAP=40;               /* Capacity on routes that use vans */

/***********************************************************************/

void moddelivery(XPRBprob prob)
{
 XPRBctr ctr, CSupply[NSupp], CDemand[NCust];
 int s,c;
 XPRBvar x[NSupp][NCust];

 int ncol, nrow, scode;
 double *lrp, *grp, *lbp, *ubp;

 XPRSprob op;

/****VARIABLES****/
 for(s=0;s<NSupp;s++) for(c=0; x[s][c]=XPRBnewvar(prob,XPRB_PL,XPRBnewname("x_s%d_%d",s,c), ctr=XPRBnewctr(prob,"OBJ",XPRB_N); for(s=0;s<NSupp;s++) Objective: Minimize total cost Set objective function Satisfy demand of each customer CDemand[c]=XPRBnewctr(prob,"Demand", Keep within supply at CSupply[s]=XPRBnewctr(prob,"Supply",XPRB_L); if(IFVAN[s][c]!=0) sense to minimization XPRB_LP,="infeasible" Solve the LP-problem status: if (XPRBgetlpstat(prob)==XPRB_LP_OPTIMAL) Get value else op=XPRBgetXPRSprob(prob); Retrieve Optimizer problem Trying fix infeasibilities lrp: (affects=and <=rows) ax aux_var=b grp:>= rows)
   ax + aux_var  = b
   ax + aux_var >= b
lbp:
   x_i + aux_var >= l
ubp:
   x_i - aux_var <= u
*/

/**** Simplified infeasibility repair:
      specifying preferences per constraint/bound type ****/

  printf("\n**** Repair infeasibility:\n");
  XPRSrepairinfeas(op, &scode, 'c', 'o', ' ', 10, 9, 0, 20, 0,001);
  printsolution2(op, scode, x);         /* Print out the solution values */

/**** Weighted infeasibility repair:
      specifying preferences for every constraint/bound separately ****/

  XPRSgetintattrib(op, XPRS_ORIGINALCOLS, &ncol);
  XPRSgetintattrib(op, XPRS_ORIGINALROWS, &nrow);
  lrp = (double *)malloc(nrow*sizeof(double));
  grp = (double *)malloc(nrow*sizeof(double));
  lbp = (double *)malloc(ncol*sizeof(double));
  ubp = (double *)malloc(ncol*sizeof(double));
  memset(lrp, 0, nrow*sizeof(double));
  memset(grp, 0, nrow*sizeof(double));
  memset(lbp, 0, ncol*sizeof(double));
  memset(ubp, 0, ncol*sizeof(double));

/* Relax bounds due to van capacity */
/* Repairweightedinfeas for upper bounds of concerned flow variables */

  for(s=0; s<NSupp; for(c=0; if(IFVAN[s][c]!=0) ubp[XPRBgetcolnum(x[s][c])]=20; Relax van ubp,='d' 0.001,="" supply limits buy in additional Repairinfeas for='less or equal' side of Supply constraints for(s=0; lrp[XPRBgetrownum(CSupply[s])]=10; demand not satisfy all Demand grp[XPRBgetrownum(CDemand[c])]=9; Read data from files void FILE int Initialize tables to COST[s][c]=0; IFVAN[s][c]=0; the file datafile=fopen(COSTFILE,"r"); 99,="g," Print out solution values XPRBvar double char *rstat[]={"relaxed optimum found",="relaxed problem infeasible" ,="relaxed problem unbounded" if(scode==0)>0,01)
     printf("%s:%g ", XPRBgetvarname(x[s][c]), XPRBgetsol(x[s][c]));
  printf("\n");
  printf("Violations:\n");
  for(c=0; c<NCust; sup=0; for(s=0; sup+=XPRBgetsol(x[s][c]); Customer dem=0; for(c=0; dem+=XPRBgetsol(x[s][c]);>SUPPLY[s]) printf(" Supplier %d: %g\n", s, dem-SUPPLY[s]);
  }
  for(s=0; s<NSupp; for(c=0; if(IFVAN[s][c]!=0 Van void int XPRBvar double char *rstat[]={"relaxed optimum found",="relaxed problem infeasible" ,="relaxed problem unbounded" if(scode==0) sol=(double Get the solution values for(s=0;>=0 && sol[XPRBgetcolnum(x[s][c])]>0,01)
     printf("%s:%g ", XPRBgetvarname(x[s][c]), sol[XPRBgetcolnum(x[s][c])]);
  printf("\n");
  printf("Violations:\n");
  for(c=0; c<NCust; sup=0; for(s=0;>=0) sup+=sol[XPRBgetcolnum(x[s][c])];
   if(sup<DEMAND[c]) Customer for(s=0; dem=0; for(c=0;>=0) dem+=sol[XPRBgetcolnum(x[s][c])];
   if(dem>SUPPLY[s]) printf("  Supplier %d: %g\n", s, dem-SUPPLY[s]);
  }
  for(s=0; s<NSupp; for(c=0; if(IFVAN[s][c]!=0>=0 &&
       VANCAP<sol[XPRBgetcolnum(x[s][c])])
     printf("  Van %d-%d: %g\n", s, c, sol[XPRBgetcolnum(x[s][c])]-VANCAP);
 }
}


/***********************************************************************/

int main(int argc, char **argv)
{
 XPRBprob prob;

 prob=XPRBnewprob("Delivery");   /* Initialize a new problem in BCL */
 readdata();                     /* Data input from file */
 moddelivery(prob);              /* Problem formulation & solving */

 return 0;
}