NAME

       interpolate - Lagrange interpolation of a function

DESCRIPTION

        The function interpolation implements the
        Lagrange interpolation of a function or a class-function.

SYNOPSYS

        template <class Function>
        field interpolate (const space& Xh, const Function& f);

EXAMPLE

        The following code compute the Lagrange interpolation
        pi_h_u of u(x).

         Float u(const point& x);
         ...
         geo omega("square");
         space Xh (omega, "P1");
         field pi_h_u = interpolate (Xh, u);

ADVANCED EXAMPLE

       It  is  possible  the  replace  the function u by a variable of the field type that represents a picewise
       polynomial function: this invocation allows the reinterpolation of  a  field  on  another  mesh  or  with
       another approximation.

         geo omega2 ("square2");
         space X2h (omega2, "P1");
         field uh2 = interpolate (X2h, pi_h_u);

IMPLEMENTATION

       // TODO: un peu general... utiliser des specialisation des classes-fonctions:
       //      function<Float(const point&)>
       //      function<point(const point&)>
       //      function<tensor(const point&)>
       template <class T, class M, class Function>
       inline
       field_basic<T,M>
       interpolate (const space_basic<T,M>& Xh, const Function& f)

rheolef-6.5                                        rheolef-6.5                             interpolate(4rheolef)