Originally posted by: xinzhangandy

Hi, I have some questions about multi-commodity network optimization. Here is the service capacity of arcs, which are identified as tuple.
tuple Arc { 
  string fromnode; 
  string tonode;
  }//arcs between any two nodes
  
 tuple Order{   OD pairs with origin and destination
 {string} st_node;
 {string} ed_node;
 {string} m_nodes;
 float volume;
 float due_time;
 }
 
 Order orders[q]=...;// multi-commodity
{Arc} arc_orders[q]=...;// possible arcs of every order
 
tuple Service {  
   Arc a;    
   float dept_time;
   float cost;
   float traveling_time; 
   float distance;
   float transport_capacity;
   float frequency;}
Service services[f] = ...;
 
The service capacity of arc(i,j) is the number of containers of all orders that can be transited by a transport service.
forall(s in f)// services tuple
  forall(k in q)//orders tuple
    forall(<i,j> in arc_orders[k])
sum(k in q)orders[k].volume*x[k][i][j] <= services[s].transport_capacity *y[s];
 
Errors include:
CPLEX(default) forall(s in 1..17) (forall(k in 1..3) (forall(<i,j> in arc_orders[k]) sum(k in 1..3) orders[k].volume*x[k][i][j] <= services[s].transport_capacity*y[s])) 
 
CPLEX(default) sum(k in 1..3) orders[k].volume*x[k][i][j] <= services[s].transport_capacity*y[s] 
 
OPL forall(<i,j> in arc_orders[k]) sum(k in 1..3) orders[k].volume*x[k][i][j] <= services[s].transport_capacity*y[s] 
 
OPL forall(s in 1..17) (forall(k in 1..3) (forall(<i,j> in arc_orders[k]) sum(k in 1..3) orders[k].volume*x[k][i][j] <= services[s].transport_capacity*y[s])) 

Hi,

let me help you with the syntax

range q=1..1;
range f=2..2;

tuple Arc {
  string fromnode;
  string tonode;
  }//arcs between any two nodes
 
 tuple Order{   
 {string} st_node;
 {string} ed_node;
 {string} m_nodes;
 float volume;
 float due_time;
 }
 
 Order orders[q]=[<{"A"},{"B"},{"C"},1,2>];// multi-commodity
{Arc} arc_orders[q]=[{<"A","B">}];// possible arcs of every order
 
tuple Service {  
   Arc a;    
   float dept_time;
   float cost;
   float traveling_time;
   float distance;   float transport_capacity;
   float frequency;};
Service services[f] = [<<"A","B">,1,2,3,4,5,6>];

{string} se={"A","B"};
 
 dvar int x[q][se][se];
 dvar int y[f];
 
subject to
{
forall(s in f)// services tuple
  forall(k in q)//orders tuple
    forall(<i,j> in arc_orders[k])
sum(k in q)orders[k].volume*x[k][i][j] <= services[s].transport_capacity *y[s];

}

works fine

So do not hesitate to post your .mod and .dat so that other users can help you

regards