From af179a81282ae17c72834146ab5a55596acc474c Mon Sep 17 00:00:00 2001
From: Umberto Zerbinati <zerbinati@maths.ox.ac.uk>
Date: Sat, 28 Oct 2023 21:57:34 +0100
Subject: [PATCH] Added Poisson test

Signed-off-by: Umberto Zerbinati <zerbinati@maths.ox.ac.uk>
---
 tests/test_fenicsx.py | 53 ++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 47 insertions(+), 6 deletions(-)

diff --git a/tests/test_fenicsx.py b/tests/test_fenicsx.py
index 0f07fed..f195147 100644
--- a/tests/test_fenicsx.py
+++ b/tests/test_fenicsx.py
@@ -7,21 +7,62 @@ def test_square_netgen():
     '''
     Testing FEniCSx interface with Netgen generating a square mesh
     '''
-    from mpi4py import MPI
-    import ngsPETSc.utils.fenicsx as fx
-    from dolfinx.io import XDMFFile
     try:
-        pass
+        from mpi4py import MPI
+        import ngsPETSc.utils.fenicsx as ngfx
+        from dolfinx.io import XDMFFile
     except ImportError:
         pytest.skip(msg="DOLFINx unavailable, skipping FENICSx test")
 
     from netgen.geom2d import SplineGeometry
     geo = SplineGeometry()
     geo.AddRectangle((0,0),(1,1))
-    geoModel = fx.GeometricModel(geo, MPI.COMM_WORLD)
-    domain  =geoModel .model_to_mesh(hmax=0.1)
+    geoModel = ngfx.GeometricModel(geo, MPI.COMM_WORLD)
+    domain  =geoModel.model_to_mesh(hmax=0.1)
     with XDMFFile(domain.comm, "XDMF/mesh.xdmf", "w") as xdmf:
         xdmf.write_mesh(domain)
 
+def test_poisson_netgen():
+    '''
+    Testing FEniCSx interface with Netgen generating a square mesh
+    '''
+    try:
+        import numpy as np
+        import ufl
+        from dolfinx import fem, mesh
+        from dolfinx.fem.petsc import LinearProblem
+        from ufl import dx, grad, inner
+        from mpi4py import MPI
+        from petsc4py.PETSc import ScalarType
+        import ngsPETSc.utils.fenicsx as ngfx
+    except ImportError:
+        pytest.skip(msg="DOLFINx unavailable, skipping FENICSx test")
+
+    from netgen.geom2d import SplineGeometry
+    geo = SplineGeometry()
+    geo.AddRectangle((0,0),(np.pi,np.pi))
+    geoModel = ngfx.GeometricModel(geo, MPI.COMM_WORLD)
+    msh  =geoModel.model_to_mesh(hmax=0.1)
+    V = fem.FunctionSpace(msh, ("Lagrange", 2))
+    facetsLR = mesh.locate_entities_boundary(msh, dim=(msh.topology.dim - 1),
+             marker=lambda x: np.logical_or(np.isclose(x[0], 0.0),
+             np.isclose(x[0], np.pi)))
+    facetsTB = mesh.locate_entities_boundary(msh, dim=(msh.topology.dim - 1),
+             marker=lambda x: np.logical_or(np.isclose(x[1], 0.0),
+             np.isclose(x[1], np.pi)))
+    facets = np.append(facetsLR,facetsTB)
+    dofs = fem.locate_dofs_topological(V=V, entity_dim=1, entities=facets)
+    bc = fem.dirichletbc(value=ScalarType(0), dofs=dofs, V=V)
+    u = ufl.TrialFunction(V)
+    v = ufl.TestFunction(V)
+    x = ufl.SpatialCoordinate(msh)
+    f = ufl.exp(ufl.sin(x[0])*ufl.sin(x[1]))
+    a = inner(grad(u), grad(v)) * dx
+    L = inner(f, v) * dx
+    problem = LinearProblem(a, L, bcs=[bc],
+              petsc_options={"ksp_type": "cg", "pc_type": "qr"})
+    problem.solve()
+
 if __name__ == "__main__":
     test_square_netgen()
+    test_poisson_netgen()