Julien Dambrine

After to save the freefem mesh I saved the vectorial solution:

{
ofstream file("velocity.bb");
file << "2 1 1 "<< u1[].n << " 2 \n";
for (int j=0;j<u1[].n ; j++)
file << u1[][j] <<" "<< u2[][j] << endl;
}

Now I need to plot velocity vectors as arrows with components (u,v) at the points (x,y).

could you give a example how to do that? Do you have any m-file? Thanks!