ex4part3.mdl

//
//  Exercise 4, Part III: Constraints
//


// create 4 variables of type real
real pressure;
real temperature;
real density;
real gasConstant;

// assign some values to the variables
pressure = 20.;       // psia
temperature = 1000.;  // rankine
density = 0.0765;     // lbm/ft3
gasConstant = 53.2;   // ft-lbf/(lbm-R)


// instantiate two Indepedent objects and three Dependent objects
Independent ind_p { 
   varName = "pressure";
} 

Independent ind_t { 
   varName = "temperature";
} 

Dependent dep_PGL { 
   eq_lhs = "pressure*144. / density";
   eq_rhs = "gasConstant * temperature";
} 

Dependent dep_temp { 
   eq_lhs = "temperature";
   eq_rhs = "2.*450. + 100.";
} 

Dependent dep_tempLimit { 
   eq_lhs = "temperature";
   eq_rhs = "800.";
} 


// place the temperature limit constraint BEFORE the dependent is made active
dep_temp.addConstraint( "dep_tempLimit", "MAX", 1, 1  ); 


// make the above Independents and Dependents active
solver.addIndependent( "ind_p" );
solver.addDependent( "dep_PGL" );

solver.addIndependent( "ind_t" );
solver.addDependent( "dep_temp" );




// execute the model
run();



// output the variable values
cout << "pressure = "    << pressure << endl;
cout << "temperature = " << temperature << endl;
cout << "density = "     << density << endl;
cout << "gasConstant = " << gasConstant << endl;