laplacep4.edp

FreeFem++可以生成高质量的有限元网格。可以用于流体力学

load "Element_P4"
load "Element_P3"
load "qf11to25"

  
mesh Th=square(10,10);
verbosity=4;

for (int i=1;i<=26;i++)
{
  cout <<" int1d order= "<< i ;
  int1d(Th,qforder=i)(1.);
}

for (int i=1;i<=26;i++)
{
 cout <<" int2d order= "<< i ;	
  int2d(Th,qforder=i)(1.);
}

verbosity=1;

 fespace Vh(Th,P4);     // P1 FE space
 Vh uh,vh;              // unkown and test function. 
 func f=1;                 //  right hand side function 
 func g=0;                 //  boundary condition function
 
 problem laplace(uh,vh) =                    //  Definion of  the problem 
    int2d(Th,qft=qf11pT)( dx(uh)*dx(vh) + dy(uh)*dy(vh) ) //  bilinear form
  - int2d(Th,qft=qf25pT)( f*vh )                          //  linear form
  + on(1,2,3,4,uh=g) ;                      //  boundary condition form

  laplace; // solve the problem plot(uh); // to see the result
  plot(uh,ps="LaplaceP4.eps",value=true);