NAME

       limiter - discontinuous Galerkin slope limiter

SYNOPSYS

        field limiter (const field& uh, options...);

DESCRIPTION

       This function returns a slope limited field for any supplied discontinuous approximation.

               geo omega ("square");
               space Xh (omega, "P1d");
               field uh (Xh);
               ...
               field vh = limiter(uh);

       This  function  is still in development as a prototype: it supports only d=1 dimension and
       k=0 or 1 polynomial  degrees.   Its  generalization  to  2D  and  3D  geometries  and  any
       polynomial degree is in development.

IMPLEMENTATION

       struct limiter_option_type {
         bool active;
         Float theta; // > 1, see Coc-1998, P. 209
         Float M;     // M=max|u''(t=0)(x)| at x where u'(t)(x)=0 :extremas
         limiter_option_type() : active(true), theta(1.5), M(1) {}
       };
       template <class T, class M>
       field_basic<T,M>
       limiter (
          const field_basic<T,M>& uh,
          const T&               bar_g_S = 1.0,
          const limiter_option_type& opt = limiter_option_type());