dune-localfunctions  2.4.1-rc2
raviartthomas02dlocalinterpolation.hh
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1 // -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
2 // vi: set et ts=4 sw=2 sts=2:
3 #ifndef DUNE_RT02DLOCALINTERPOLATION_HH
4 #define DUNE_RT02DLOCALINTERPOLATION_HH
5 
6 #include <cmath>
7 #include <vector>
8 #include <dune/common/exceptions.hh>
9 
10 namespace Dune
11 {
12  template<class LB>
14  {
15  public:
16 
19  {
20  sign0 = sign1 = sign2 = 1.0;
21  }
22 
24  RT02DLocalInterpolation (unsigned int s)
25  {
26  sign0 = sign1 = sign2 = 1.0;
27  if (s&1) sign0 *= -1.0;
28  if (s&2) sign1 *= -1.0;
29  if (s&4) sign2 *= -1.0;
30  m0[0] = 0.5; m0[1] = 0.0;
31  m1[0] = 0.0; m1[1] = 0.5;
32  m2[0] = 0.5; m2[1] = 0.5;
33  n0[0] = 0.0; n0[1] = -1.0;
34  n1[0] = -1.0; n1[1] = 0.0;
35  n2[0] = 1.0/sqrt(2.0); n2[1] = 1.0/sqrt(2.0);
36  c0 = ( 0.5*n0[0] - 1.0*n0[1]);
37  c1 = (-1.0*n1[0] + 0.5*n1[1]);
38  c2 = ( 0.5*n2[0] + 0.5*n2[1]);
39  }
40 
41  template<typename F, typename C>
42  void interpolate (const F& f, std::vector<C>& out) const
43  {
44  // f gives v*outer normal at a point on the edge!
45  typename F::Traits::RangeType y;
46 
47  out.resize(3);
48 
49  f.evaluate(m0,y); out[0] = (y[0]*n0[0]+y[1]*n0[1])*sign0/c0;
50  f.evaluate(m1,y); out[1] = (y[0]*n1[0]+y[1]*n1[1])*sign1/c1;
51  f.evaluate(m2,y); out[2] = (y[0]*n2[0]+y[1]*n2[1])*sign2/c2;
52  }
53 
54  private:
55  typename LB::Traits::RangeFieldType sign0,sign1,sign2;
56  typename LB::Traits::DomainType m0,m1,m2;
57  typename LB::Traits::DomainType n0,n1,n2;
58  typename LB::Traits::RangeFieldType c0,c1,c2;
59  };
60 }
61 
62 #endif
RT02DLocalInterpolation()
Standard constructor.
Definition: raviartthomas02dlocalinterpolation.hh:18
Definition: raviartthomas02dlocalinterpolation.hh:13
RT02DLocalInterpolation(unsigned int s)
Make set numer s, where 0<=s<8.
Definition: raviartthomas02dlocalinterpolation.hh:24
void interpolate(const F &f, std::vector< C > &out) const
Definition: raviartthomas02dlocalinterpolation.hh:42