Added mean operator on the skeleton

src/Integration/SkeletonCellFields.jl

@@ -8,6 +8,7 @@ export SkeletonCellVector
 export SkeletonCellMatrix
 
 export jump
+export mean
 import Gridap: restrict
 import Gridap: gradient
 import Gridap: inner
@@ -50,6 +51,19 @@ function jump(sp::SkeletonPair{Z,T,2}) where {Z,T}
   SkeletonCellBasis(cf1, -cf2)
 end
 
+function mean(sp::SkeletonPair{Z,T,1}) where {Z,T}
+  cf1 = sp.cellfield1
+  cf2 = sp.cellfield2
+  0.5*(cf1 + cf2)
+end
+
+function mean(sp::SkeletonPair{Z,T,2}) where {Z,T}
+  cf1 = sp.cellfield1
+  cf2 = sp.cellfield2
+  SkeletonCellBasis(0.5*cf1, 0.5*cf2)
+end
+
+
 struct SkeletonCellBasis{Z,T}
   cellbasis1::CellBasis{Z,T}
   cellbasis2::CellBasis{Z,T}

test/IntegrationTests/SkeletonCellFieldsTests.jl

@@ -32,18 +32,30 @@ suh = restrict(uh,strian)
 jsu = jump(su)
 jsu_s = evaluate(jsu,s)
 
+msu = mean(su)
+msu_s = evaluate(msu,s)
+
 jsuh = jump(suh)
 jsuh_s = evaluate(jsuh,s)
 
+msuh = mean(suh)
+msuh_s = evaluate(msuh,s)
+
 jsu_grad = jump(∇(su))
 jsu_grad_s = evaluate(jsu_grad,s)
 
+msu_grad = mean(∇(su))
+msu_grad_s = evaluate(msu_grad,s)
+
 jsuh_grad = jump(∇(suh))
 jsuh_grad_s = evaluate(jsuh_grad,s)
 
+msuh_grad = mean(∇(suh))
+msuh_grad_s = evaluate(msuh_grad,s)
+
 #writevtk(strian,"strian",cellfields=[
-# "jumpu"=>jsu,"jumpu_grad"=>jsu_grad,
-# "jumph"=>jsuh,"jumpuh_grad"=>jsuh_grad ])
+# "jumpu"=>jsu,"meanu"=>msu,"jumpu_grad"=>jsu_grad,"meanu_grad"=>msu_grad,
+# "jumph"=>jsuh,"meanh"=>msuh,"jumpuh_grad"=>jsuh_grad,"meanh_grad"=>msuh_grad ])
 
 v = CellBasis(trian)
 du = v
@@ -58,6 +70,12 @@ cv = integrate(cm,strian,squad)
 _ = collect(cv.cellvector1)
 _ = collect(cv.cellvector2)
 
+cm = inner(mean(v_Γ),jump(u_Γ))
+
+cv = integrate(cm,strian,squad)
+_ = collect(cv.cellvector1)
+_ = collect(cv.cellvector2)
+
 cm = inner(jump(v_Γ),jump(du_Γ))
 
 cv = integrate(cm,strian,squad)
@@ -66,6 +84,14 @@ _ = collect(cv.cellmatrix12)
 _ = collect(cv.cellmatrix21)
 _ = collect(cv.cellmatrix22)
 
+cm = inner(mean(v_Γ),jump(du_Γ))
+
+cv = integrate(cm,strian,squad)
+_ = collect(cv.cellmatrix11)
+_ = collect(cv.cellmatrix12)
+_ = collect(cv.cellmatrix21)
+_ = collect(cv.cellmatrix22)
+
 cm = inner(jump(u_Γ),jump(u_Γ))
 cv = integrate(cm,strian,squad)
 _ = collect(cv)
@@ -78,4 +104,8 @@ z = Point(0.0,0.0,0.0)
 zs = fill(z,4)
 @test all([ xi .+ 1 ≈ zs .+ 1 for xi in x ])
 
+x = evaluate(mean(phi_Γ),s)
+x2 = evaluate(phi_Γ.cellfield1,s)
+@test x ≈ x2
+
 end # module