// \$Id\$ #include "flopc.hpp" using namespace flopc; #include /* A sample problem to demonstrate the power of modeling systems Fourer, R, Gay, D M, and Kernighan, B W, AMPL: A Mathematical Programming Language. AT\&T Bell Laboratories, Murray Hill, New Jersey, 1987. */ int main() { MP_model::getDefaultModel().setSolver(new OsiCbcSolverInterface); MP_model::getDefaultModel().verbose(); enum {iron, nickel, numRaw}; enum {nuts, bolts, washers, numPrd}; const int numT = 4; MP_set prd(numPrd), // products / nuts, bolts, washers / raw(numRaw), // raw materials / iron, nickel / TL(numT+1); // extended t / 1 * 5 / MP_subset<1> T(TL), // periods / 1 * 4 / first(TL), // / 1 / last(TL); // / 5 / T.insert(0); T.insert(1); T.insert(2); T.insert(3); first.insert(0); last.insert(4); MP_data istock(raw); // initial stock / iron 35.8 , nickel 7.32 / MP_data scost(raw); // storage cost / iron .03, nickel .025 / MP_data rvalue(raw); // residual value / iron .02, nickel -.01 / istock(iron) = 35.8; istock(nickel) = 7.32; scost(iron) = 0.03; scost(nickel) = 0.025; rvalue(iron) = 0.02; rvalue(nickel) =-0.01; double m = 123; // maximum production MP_data units(raw,prd); // raw material inputs to produce a unit of product double avalue[numRaw][numPrd] = {{ .79, .83, .92 }, { .21, .17, .08 }}; units.value(&avalue[0][0]); MP_data profit(prd,T); // profit double cvalue[numPrd][numT] = {{ 1.73, 1.8, 1.6, 2.2 }, { 1.82, 1.9, 1.7, .95}, { 1.05, 1.1, .95, 1.33}}; profit.value(&cvalue[0][0]); MP_variable x(prd,TL); // production level MP_variable s(raw,TL); // storage at beginning of period MP_index p,r,t; MP_constraint limit(T), // capacity constraint balance(raw,TL); // raw material balance limit(T) = sum(prd(p), x(p,T)) <= m; balance(r,TL+1) = s(r,TL+1) == s(r,TL) - sum(prd(p), units(r,p)*x(p,TL)); s.upperLimit(r,0) = istock(r); // MP_model::default_model.verbose(); maximize( sum(T(t), sum(prd(p), profit(p,t)*x(p,t)) - sum(raw(r), scost(r)*s(r,t) )) + sum(raw(r), rvalue(r)*s(r,numT)) ); assert(MP_model::getDefaultModel()->getNumRows()==14); assert(MP_model::getDefaultModel()->getNumCols()==25); assert(MP_model::getDefaultModel()->getNumElements()==60); assert(MP_model::getDefaultModel()->getObjValue()>=79.3412 && MP_model::getDefaultModel()->getObjValue()<=79.3414); x.display(); s.display(); cout<<"Test ampl passed."<