dirichlet_expression -> interpolate_expression

There is way more reasons to interpolate a function into the
solution vector and we cover them with one code path:
* Dirichlet boundary conditions (strong ones)
* Initial conditions for instationary expressions
* Initial guesses for Newton solvers

test/poisson/dimension-grid-variations/poisson_2d_cg_triangle.ufl

@@ -11,4 +11,4 @@ v = TestFunction(V)
 forms = [(inner(grad(u), grad(v)) - f*v)*dx]
 exact_solution = g
 is_dirichlet = 1
-dirichlet_expression = g
+interpolate_expression = g

test/poisson/dimension-grid-variations/poisson_3d_cg_hexahedron.ufl

@@ -11,4 +11,4 @@ v = TestFunction(V)
 forms = [(inner(grad(u), grad(v)) - f*v)*dx]
 exact_solution = g
 is_dirichlet = 1
-dirichlet_expression = g
+interpolate_expression = g

test/poisson/dimension-grid-variations/poisson_3d_cg_tetrahedron.ufl

@@ -11,4 +11,4 @@ v = TestFunction(V)
 forms = [(inner(grad(u), grad(v)) - f*v)*dx]
 exact_solution = g
 is_dirichlet = 1
-dirichlet_expression = g
+interpolate_expression = g

test/poisson/poisson.ufl

@@ -13,5 +13,5 @@ v = TestFunction(V)
 
 forms = [(inner(grad(u), grad(v)) - f*v)*dx]
 exact_solution = g
-dirichlet_expression = g
+interpolate_expression = g
 is_dirichlet = 1
\ No newline at end of file

test/poisson/poisson_neumann.ufl

@@ -19,4 +19,4 @@ ds = ds(subdomain_data=bctype)
 forms = [(inner(grad(u), grad(v)) - f*v)*dx - j*v*ds(0)]
 exact_solution = g
 is_dirichlet = bctype
-dirichlet_expression = g
+interpolate_expression = g
\ No newline at end of file

test/poisson/poisson_tensor.ufl

@@ -15,4 +15,4 @@ v = TestFunction(V)
 forms = [(inner(A*grad(u), grad(v)) + c*u*v -f*v)*dx]
 exact_solution = g
 is_dirichlet = 1
-dirichlet_expression = g
+interpolate_expression = g
\ No newline at end of file

test/stokes/stokes.ufl

@@ -15,5 +15,5 @@ r = (inner(grad(v), grad(u)) - div(v)*p - q*div(u))*dx
 
 forms = [r]
 is_dirichlet = v_bctype, v_bctype, 0
-dirichlet_expression = g_v, None
+interpolate_expression = g_v, None
 exact_solution = g_v, 8.*(1.-x[0])
\ No newline at end of file

test/stokes/stokes_3d_quadrilateral.ufl

@@ -16,4 +16,4 @@ r = (inner(grad(v), grad(u)) - div(v)*p - q*div(u))*dx
 forms = [r]
 exact_solution = g_v, 8.*(1.-x[0])
 is_dirichlet = v_bctype, v_bctype, v_bctype, 0
-dirichlet_expression = g_v, None
+interpolate_expression = g_v, None

test/stokes/stokes_quadrilateral.ufl

@@ -15,5 +15,5 @@ r = (inner(grad(v), grad(u)) - div(v)*p - q*div(u))*dx
 
 forms = [r]
 is_dirichlet = v_bctype, v_bctype, 0
-dirichlet_expression = g_v, None
+interpolate_expression = g_v, None
 exact_solution = g_v, 8.*(1.-x[0])

test/stokes/stokes_stress.ufl

@@ -16,5 +16,5 @@ r = (inner(grad(v), S) + inner(grad(u) - S, T) - div(v)*p - q*div(u))*dx
 
 forms = [r]
 is_dirichlet = v_bctype, v_bctype, 0, 0, 0, 0, 0
-dirichlet_expression = 4*x[1]*(1.-x[1]), 0.0, None, None, None, None, None
+interpolate_expression = 4*x[1]*(1.-x[1]), 0.0, None, None, None, None, None
 exact_solution = 4*x[1]*(1.-x[1]), 0.0, 8*(1.-x[0]), 0.0, 0.0, -1.*8*x[1] + 4., 0.0
\ No newline at end of file

test/stokes/stokes_stress_sym.ufl

@@ -22,5 +22,5 @@ r = (inner(grad(v), S) + inner(2*sym(grad(u)) - S, T) - div(v)*p - q*div(u))*dx
 
 forms = [r]
 is_dirichlet = v_bctype, v_bctype, 0, 0, 0, 0
-dirichlet_expression = 4*x[1]*(1.-x[1]), 0.0, None, None, None, None
+interpolate_expression = 4*x[1]*(1.-x[1]), 0.0, None, None, None, None
 exact_solution = 4*x[1]*(1.-x[1]), 0.0, 8*(1.-x[0]), 0.0, 0.0, -1.*8*x[1] + 4.
\ No newline at end of file

test/stokes/stokes_sym.ufl

@@ -18,5 +18,5 @@ r = (inner(2*sym(grad(u)), grad(v)) - div(v)*p - q*div(u))*dx - inner(grad(u).T*
 
 forms = [r]
 is_dirichlet = v_bctype, v_bctype, 0
-dirichlet_expression = g_v, None
+interpolate_expression = g_v, None
 exact_solution = g_v, 8.*(1.-x[0])
\ No newline at end of file

test/sumfact/hyperbolic/linearacoustics.ufl

@@ -29,4 +29,4 @@ r = -1. * inner(flux, grad(v))*dx \
   + inner(u, v)*ds
 
 forms = [mass, r]
-dirichlet_expression = f, 0.0, 0.0
+interpolate_expression = f, 0.0, 0.0

test/sumfact/hyperbolic/lineartransport.ufl

@@ -28,4 +28,4 @@ r = -1.*u*inner(beta, grad(v))*dx \
 forms = [mass, r]
 exact_solution = 0.0
 is_dirichlet = dirichlet
-dirichlet_expression = initial
+interpolate_expression = initial
\ No newline at end of file

test/sumfact/hyperbolic/shallowwater.ufl

@@ -36,4 +36,4 @@ r = -1. * inner(flux, grad(v))*dx \
   + inner(boundary_flux, v)*ds
 
 forms = [mass, r]
-dirichlet_expression = f, 0.0, 0.0
+interpolate_expression = f, 0.0, 0.0

test/sumfact/poisson/poisson_2d.ufl

@@ -15,4 +15,4 @@ v = TestFunction(V)
 forms = [(inner(grad(u), grad(v)) - f*v)*dx]
 exact_solution = g
 is_dirichlet = 1
-dirichlet_expression = g
+interpolate_expression = g

test/sumfact/poisson/poisson_3d.ufl

@@ -12,4 +12,4 @@ v = TestFunction(V)
 forms = [(inner(grad(u), grad(v)) - f*v)*dx]
 exact_solution = g
 is_dirichlet = 1
-dirichlet_expression = g
+interpolate_expression = g

test/sumfact/stokes/stokes.ufl

@@ -16,5 +16,5 @@ r = (inner(grad(v), grad(u)) - div(v)*p - q*div(u))*dx
 
 forms = [r]
 exact_solution = g_v, 8.*(1.-x[0])
-dirichlet_expression = g_v, None
+interpolate_expression = g_v, None
 is_dirichlet = v_bctype, v_bctype, None
\ No newline at end of file