model:
!3发点4收点运输问题;
sets:
warehouses/wh1..wh3/: capacity;
vendors/v1..v4/: demand;
links(warehouses,vendors): cost, volume;
endsets
!目标函数;
min=@sum(links: cost*volume);
!需求约束;
@for(vendors(J):
@sum(warehouses(I): volume(I,J))=demand(J));
!产量约束;
@for(warehouses(I):
@sum(vendors(J): volume(I,J))<=capacity(I));
!这里是数据;
data:
capacity=100 100 100;
demand=14 3 16 4;
cost=3 5 2 6
7 4 8 9
10 2 1 8;
enddata
end
我想加个约束条件:y1,y2,y3分别表示三家工厂是否开办,若y1=0,即工厂y1不提供给任何顾客产品量,则工厂y1不开办;y1=1,即工厂y1提供给顾客产品量,则工厂y1开办。有谁知道怎么加吗?