/*******************************************************
Mosel Example Problems
======================
file scenar.c
`````````````
Executing different scenarios.
(c) 2008 Fair Isaac Corporation
author: S. Heipcke, 2002
********************************************************/
#include <stdio.h>
#include <string.h>
#include "xprm_mc.h"
int execscenar(const char *FILENAME, double WEIGHT);
#define NSUP 6
double obj, capuse[NSUP], CAP[NSUP];
char SUPNAME[NSUP][64];
int main()
{
int NSCENAR = 5;
const char *DEMDATA[] = {"dem1.dat", "dem2.dat", "dem3.dat", "dem4.dat",
"dem5.dat"};
double WEIGHT[] = {0.4, 0.15, 0.1, 0.25, 0.1};
int i,s;
double fact = 0;
if(XPRMinit()) /* Initialize Mosel */
return 1;
/* Execute all scenarios */
for(i=0;i<NSCENAR;i++) if(execscenar(DEMDATA[i], WEIGHT[i])) fact+=WEIGHT[i];
fact= 1/fact;
/* Print out aggregate results */
printf("Weighted average objective: %g\n", obj*fact);
for(s=0;s<NSUP;s++)
printf("%s: %g (%g%% of %g)\n", SUPNAME[s], capuse[s]*fact,
capuse[s]*fact/CAP[s]*100, CAP[s]);
return 0;
}
/**** Run a scenario and retrieve its results ****/
int execscenar(const char *FILENAME, double WEIGHT)
{
XPRMmodel mod;
XPRMalltypes rvalue;
XPRMarray darr, varr;
XPRMset set[1];
XPRMmpvar x;
int indices[2], result;
char params[128];
sprintf(params, "DEMFILE=Data/%s", FILENAME);
/* Execute model file 'scenar.mos' */
if(XPRMexecmod(NULL,"scenar.mos",params,&result,&mod))
{ printf("Problem %s not executed.\n", FILENAME); return 0; }
/* Test whether a solution is found */
if((XPRMgetprobstat(mod)&XPRM_PBRES)!=XPRM_PBOPT)
{ printf("Demand scenario %s is infeasible.\n", FILENAME); return 0; }
/* Get the objective function value */
obj += WEIGHT*XPRMgetobjval(mod);
/* At first execution: get 'CAP' data and the 'Suppliers' index set for
pretty solution printout */
if(!strcmp(FILENAME, "dem1.dat"))
{
XPRMfindident(mod, "CAP", &rvalue); /* Get the model object 'CAP' */
darr = rvalue.array;
XPRMgetarrsets(darr, set); /* Get the index set of 'CAP' */
XPRMgetfirstarrentry(darr, indices); /* Get the first index tuple */
do
{
strcpy(SUPNAME[indices[0]-1],
XPRMgetelsetval(set[0], indices[0], &rvalue)->string);
XPRMgetarrval(darr, indices, &(CAP[indices[0]-1]));
} while(!XPRMgetnextarrentry(darr, indices)); /* Get the next index tuple */
}
/* At every execution: get the solution for variables 'x' */
XPRMfindident(mod, "x", &rvalue); /* Get the model object 'x' */
varr = rvalue.array;
XPRMgetfirstarrtruentry(varr, indices); /* Get the first entry of array varr
(we know that the array is sparse
and has two dimensions) */
do
{
XPRMgetarrval(varr, indices, &x); /* Get the corresponding variable */
capuse[indices[0]-1] += WEIGHT*XPRMgetvsol(mod,x); /* Save the sol. value */
/* printf("<%d,%d:%g>\n", indices[0], indices[1], XPRMgetvsol(mod,x)); */
} while(!XPRMgetnextarrtruentry(varr, indices));
/* Get the next index tuple */
return 1;
}
|
(!*******************************************************
Mosel Example Problems
======================
file scenar.mos
```````````````
Transportation example (multiple scenarios).
(c) 2008 Fair Isaac Corporation
author: S.Heipcke, 2002, rev. June 2018
*********************************************************!)
model "Scenario"
uses "mmxprs"
parameters
DEMFILE="Data/dem1.dat"
end-parameters
public declarations
Suppliers: set of string ! Set of suppliers
Customers: set of string ! Set of customers
COST: dynamic array(Suppliers,Customers) of real ! Cost per supplier-customer pair
CAP: array(Suppliers) of real ! Production capacity
DEM: array(Customers) of real ! Demand by customers
x: dynamic array(Suppliers,Customers) of mpvar ! Transported quantities
end-declarations
initializations from "Data/supply.dat"
COST CAP
end-initializations
initializations from DEMFILE
DEM as "DEMAND"
end-initializations
forall(s in Suppliers, c in Customers | exists(COST(s,c))) create(x(s,c))
! Objective: minimize total cost
MinCost:=
sum(s in Suppliers, c in Customers | exists(COST(s,c))) COST(s,c) * x(s,c)
! Limits on production capacities
forall(s in Suppliers) sum(c in Customers) x(s,c) <= CAP(s)
! Satisfy customer demands
forall(c in Customers) sum(s in Suppliers) x(s,c) >= DEM(c)
minimize(MinCost)
writeln("Demand scenario: ", DEMFILE)
(!
forall(s in Suppliers, c in Customers)
if(getsol(x(s,c))>0) then
writeln(s," (", CAP(s), ") -> ", c, " (", DEM(c), "): ",
getsol(x(s,c)) )
end-if
!)
if(getprobstat=XPRS_OPT) then
writeln("Total cost: ", getobjval)
forall(s in Suppliers) writeln(s, ": ", getsol(sum(c in Customers) x(s,c)) )
end-if
end-model
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