invoke

OPL keyword for scripting statements in data files

Purpose

OPL keyword to call an IBM ILOG Script function after a data initialization.

context
Data files (.dat)

Syntax

Invoke_opt: /* empty */
          | Invoke

Invoke: "invoke" Id

Description

This keyword allows you to call an IBM ILOG Script function after a data initialization. For single values, an additional step is required (see the second code example).

Example 1

In the model file:

float t[1..3]=...;

execute
{
   writeln("after invoke");
   writeln("t=",t);
}

In the data file:

prepare {                                      
   function transformIntoHours(t, name) {   
      writeln("t=",t);                
      for(var a=1;a<=t.size;a++) t[a]=t[a]/60;
      return true;
   }   
}
// t is given in minutes and has to be converted into hours
t = [600,240,150] invoke transformIntoHours;

Result:

// The display is
// t= [600 240 150]
// after invoke
// t= [10 4 2.5]

Example 2 (single value)

If in the model file you have:

int t=...;
execute
{
 writeln(t);
}

and in the data file you have:

prepare {
   function f(t, name) {
      t=6;
      writeln(t);
      return true;
   }
}

t = 5 invoke f;

the result is

6
5

because of the properties of function in IBM ILOG Script.

To obtain the expected result

5
6

you must replace t=6 with thisOplModel[name]=6.

See reference information on IBM ILOG Script in Language structure.