readmesh.edp

FreeFem++可以生成高质量的有限元网格。可以用于流体力学

border floor(t=0,1){ x=t; y=0; label=1;}; // the unit square
border right(t=0,1){ x=1; y=t; label=5;};
border ceiling(t=1,0){ x=t; y=1; label=5;};
border left(t=1,0){ x=0; y=t; label=5;};
int n=10;
mesh th= buildmesh(floor(n)+right(n)+ceiling(n)+left(n));
savemesh(th,"toto.am_fmt");// format "formated Marrocco"
savemesh(th,"toto.Th");//format database "bamg"
savemesh(th,"toto.dbg");//format debug
savemesh(th,"toto.msh"); //format freefem
mesh th2 = readmesh("toto.msh");
fespace femp1(th,P1);
femp1 f = sin(x)*cos(y),g;
{

ofstream file("f.txt");
file.precision(16);
file << f[] << endl;
}
{
ifstream file("f.txt");
file >> g[] ;
}
fespace Vh2(th2,P1);
Vh2 u,v;
plot(g);
solve pb(u,v) =
    int2d(th2)( u*v -dx(u)*dx(v)-dy(u)*dy(v) )
  + int2d(th2)(-g*v) 
  + int1d(th2,5)( -g*v)
  + on(1,u=0) ;
plot (th2,u);
cout << " (u[],u[]) = " << (u[]'*u[]) << endl; 
{
ofstream file("u.txt");
file << u[] << endl;
}