Hello all,

@prj, @frederichecht, where I could find all the options to impose dirichlet boundary conditions with “on” like this: on(1, u=g, tgv=xx) with xx=-1; -2; -10 ; …

Thank you for your help,

Best regards,

Loïc,

Hello all,

@prj, @frederichecht, where I could find all the options to impose dirichlet boundary conditions with “on” like this: on(1, u=g, tgv=xx) with xx=-1; -2; -10 ; …

Thank you for your help,

Best regards,

Loïc,

Thank you for your answer!

I will add a small example in tutorial to see

```
load "msh3"
meshL Th = segment(2);
real [int] vtgv = [ -20,-10,-2,-1,0, tgv];
varf va(u,v)= int1d(Th)(u*v*24.)+on(1,2,u=0);// mul by 12 to have integer coef ..
// label : 1 on first DoF O
// 2 on last DoF 2
// tgv : -20 put to zero of row and colnum of Dof with label 1 or 2
fespace Vh(Th,P1);
for [i,tgvi:vtgv]
{
matrix A= va(Vh,Vh,tgv=tgvi);
real[int,int] F(3,3);
F=0.;
for [i,j,aij:A]
F(i,j) = aij;
cout << " tgv = " << tgvi << " matrix= " << F << "\n\n\n";
}
```

the output is :

```
-- FESpace: Nb of Nodes 3 Nb of DoF 3
tgv = -20 matrix= 3 3
0 0 0
0 8 0
0 0 0
tgv = -10 matrix= 3 3
0 0 0
2 8 2
0 0 0
tgv = -2 matrix= 3 3
1 0 0
0 8 0
0 0 1
tgv = -1 matrix= 3 3
1 0 0
2 8 2
0 0 1
tgv = 0 matrix= 3 3
0 2 0
2 8 2
0 2 0
tgv = 1e+30 matrix= 3 3
1e+30 2 0
2 8 2
0 2 1e+30
times: compile 0.007039s, execution 0.000266s, mpirank:0
```

1 Like

Thank you for this explanation !