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Retrieving data from a Mosel model

Description
mmexset.c: Using sets in Mosel (requires burglari.bim)
  • retrieve a set by its model name
  • get the set size
  • get first and last set element
  • get the name or index of a set element
mmexarr.c: Using arrays in Mosel (requires trans.bim)
  • compare index tuples
  • retrieve an array by its model name
  • get array size and number of dimensions
  • get indices of first and last array entries
  • get (value of) array entries
  • check whether an index tuple lies in the range of an array
mmexas.c: Using arrays with index sets (requires trans.bim)
  • get indexing sets of an array
  • get array type
  • enumerate array entries in usual and transposed order
  • enumerate true array entries
mmexlst.c: Using lists in Mosel (requires euler.mos and euler.dat)
  • retrieve a list by its model name
  • get the list size
  • enumerate the list elements
  • get value of list element
mmexrec.c: Using records in Mosel (requires burglar_rec.mos and burglar_rec.dat)
  • retrieve an array of records (user type) by its model name
  • retrieve the record field information (field name, type, and number)
  • enumerate the array of records
  • for each array entry (record) get the value of all its fields
mmexprob.c: Accessing problems and solution information with Mosel (requires blend2.bim)
  • export problem to a file (MPS or LP format)
  • get problem status
  • get objective function value
  • get primal/dual solution values, and constraint activity
Note that these examples require the provided mos files to be pre-compiled.

Further explanation of this example: 'Mosel Library Reference Manual', Section 1.2 Post processing interface


Source Files

Data Files





mmexprob.c

/********************************************************/
/*  Mosel Library Examples                              */
/*  ======================                              */
/*                                                      */
/*  file mmexprob.c                                     */
/*  ```````````````                                     */
/*  Example for the use of the Mosel libraries          */
/*  (accessing problems and solution information)       */
/*                                                      */
/*  (c) 2008 Fair Isaac Corporation                     */
/*      author: S. Heipcke, 2001                        */
/********************************************************/

#include <stdio.h>
#include "xprm_rt.h"

int main()
{
 XPRMmodel mod;
 XPRMalltypes rvalue;
 XPRMarray varr, darr;
 XPRMmpvar x;
 XPRMlinctr lgrade;
 double cost;
 int result, type;
 int indices[1],i;

 i=XPRMinit();
 if((i!=0)&&(i!=32))                                   /* Initialize Mosel */
  return 1;

 if((mod=XPRMloadmod("Models/blend2.bim",NULL))==NULL) /* Load a BIM file */
  return 2;
 
 if(XPRMrunmod(mod,&result,NULL))         /* Run the model (it includes 
                                             optimization) */
  return 3;

 XPRMexportprob(mod,"p","blend",NULL);    /* Export problem to a file in LP 
                                             format (maximization) */

 if((XPRMgetprobstat(mod)&XPRM_PBRES)!=XPRM_PBOPT)
  return 5;                             /* Test whether a solution is found */

 printf("Objective value: %g\n", XPRMgetobjval(mod));
                                        /* Print the objective function value */

 type=XPRMfindident(mod,"x",&rvalue);     /* Get the model object named 'x' */
 if((XPRM_TYP(type)!=XPRM_TYP_MPVAR)||    /* Check the type: */
    (XPRM_STR(type)!=XPRM_STR_ARR))       /* it must be an array of unknowns */
  return 5;
 varr=rvalue.array;

 type=XPRMfindident(mod,"COST",&rvalue);  /* Get the model object 'COST' */
 if((XPRM_TYP(type)!=XPRM_TYP_REAL)||     /* Check the type: */
    (XPRM_STR(type)!=XPRM_STR_ARR))       /* it must be an array of reals */
  return 6;
 darr=rvalue.array;
   
 XPRMgetfirstarrentry(varr, indices);  /* Get the first entry of the array varr
                                          (we know that the array is dense 
                                          and has a single dimension) */
 do
 {
  XPRMgetarrval(varr,indices,&x);         /* Get the a variable from varr */
  XPRMgetarrval(darr,indices,&cost);      /* Get the corresponding cost value */
  printf("x(%d)=%g (COST: %g)\n",indices[0],
   XPRMgetvsol(mod,x), cost);            /* Print the solution value */
 } while(!XPRMgetnextarrentry(varr, indices));  /* Get the next index */
 
 type=XPRMfindident(mod,"LoGrade",&rvalue);/* Get the model object 'LoGrade' */
 if((XPRM_TYP(type)!=XPRM_TYP_LINCTR)||    /* Check the type: */
    (XPRM_STR(type)!=XPRM_STR_REF))        /* it must be a reference to a linear
                                              constraint */
  return 7;
 lgrade=rvalue.linctr;

 printf("LoGrade: activity=%g, dual=%g\n",
   XPRMgetact(mod,lgrade), XPRMgetdual(mod,lgrade));
                                      /* Print the activity and dual values */

 XPRMresetmod(mod);
 return 0;
}

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