mary
May 26, 2023, 10:06pm
1
i want to assemble a matrix from FE space and trial but it gives me errors. does anyone know about the solution?

```
uApp1(x) = VectorValue(0.0,0.0)
uApp2(x) = VectorValue(0.0,0.0)
uApp3(x) = VectorValue(0.0,-vAppMax)
U_Disp = TrialFESpace(V0_Disp ,[uApp1 ,uApp2 ,uApp3])
order = 1
reffe_Disp = ReferenceFE(lagrangian ,VectorValue{2,Float64},order)
V0_Disp = TestFESpace(model,reffe_Disp;conformity =:H1,
dirichlet_tags = ["LeftSupport","RightSupport","LoadLine"],
dirichlet_masks =[(false ,true), (true ,true), (false ,true)])
# uh = zero(V0_Disp)
assemble_matrix(fem_params.U_Disp, fem_params.V0_Disp)
```

i think it is a simple question for those who know julia well but not for me as a new user.
thank you for your help

Hi Mary! Could you provide a complete reproducible example? I’m not sure what packages you’re using, or which error you’re getting, which makes it hard to debug

mary
May 27, 2023, 5:30pm
3
Hi gdalle! Thank you for your response. sure i hope this works

```
using GridapGmsh
using Gridap
using Gridap.Geometry
using LinearAlgebra
using Gridap.Fields
using Gridap.TensorValues
const vAppMax = 0.1
order = 1
reffe_Disp = ReferenceFE(lagrangian ,VectorValue{2,Float64},order)
V0_Disp = TestFESpace(model,reffe_Disp;conformity =:H1,
dirichlet_tags = ["LeftSupport","RightSupport","LoadLine"],
dirichlet_masks =[(false ,true), (true ,true), (false ,true)])
uApp1(x) = VectorValue(0.0,0.0)
uApp2(x) = VectorValue(0.0,0.0)
uApp3(x) = VectorValue(0.0,-vAppMax)
U_Disp = TrialFESpace(V0_Disp ,[uApp1 ,uApp2 ,uApp3])
assemble_matrix(fem_params.U_Disp, fem_params.V0_Disp) do u, v
(0.5 * (∫(C_mat⊙(∇(u) ⋅ ∇(v)))fem_params.dΩ))
end
```