Functions

Let

  double (*function)(double x);

be a pointer to a function. Then,

  Function1<double,double> F(function);

defines a function which can be used in an expression.

Example:

  Variable<double,staggered,staggered,staggered> u_exact(grid);

  Coordinate<WE_dir,Grid_uniform_one_d> X(grid);
  Coordinate<SN_dir,Grid_uniform_one_d> Y(grid);

  Function1<double,double> Cos(cos);             // definition of a function
  u_exact = Cos(X)*Cos(Y);                       // exact solution
                                                 // of an equation

Example:

   ....
   double eps(double x, double y, double z) {
       if(z<0.3) return 2.0;
       return 4.0
   }

   ....

   { ...
  Variable<double,staggered,staggered,staggered> epsAtCell(grid);

  Coordinate<WE_dir,Grid_uniform_one_d> X(grid);
  Coordinate<SN_dir,Grid_uniform_one_d> Y(grid);
  Coordinate<SN_dir,Grid_uniform_one_d> Z(grid);

  Function3<double,double> Eps(eps);             // definition of a function
  EpsAtCell = Eps(X,Y,Z); 
   ... 
  }
                        

Last modified: Tue Feb 22 11:08:52 MET 2000