def test_vtk_quads():
points = vtk.vtkPoints()
points.InsertNextPoint(0.0, 0.0, 0.0)
points.InsertNextPoint(1.0, 0.0, 0.0)
points.InsertNextPoint(2.0, 0.0, 0.0)
points.InsertNextPoint(0.0, 1.0, 0.0)
points.InsertNextPoint(1.0, 1.0, 0.0)
points.InsertNextPoint(2.0, 1.0, 0.0)
grid = vtk.vtkUnstructuredGrid()
grid.SetPoints(points)
grid.InsertNextCell(vtk.VTK_QUAD, 4, [0, 3, 4, 1])
grid.InsertNextCell(vtk.VTK_QUAD, 4, [1, 4, 5, 2])
builder = MatrixBuilder()
data, rows, cols = mass_matrix(grid, [0, 1], parallel=False)
builder.add(data, rows, cols, 1)
assert np.allclose(
builder.build().toarray(),
np.array([
[1 / 9, 1 / 18, 0, 1 / 18, 1 / 36, 0],
[1 / 18, 2 / 9, 1 / 18, 1 / 36, 1 / 9, 1 / 36],
[0, 1 / 18, 1 / 9, 0, 1 / 36, 1 / 18],
[1 / 18, 1 / 36, 0, 1 / 9, 1 / 18, 0],
[1 / 36, 1 / 9, 1 / 36, 1 / 18, 2 / 9, 1 / 18],
[0, 1 / 36, 1 / 18, 0, 1 / 18, 1 / 9],
]))
def test_vtk_triangles():
points = vtk.vtkPoints()
points.InsertNextPoint(0.0, 0.0, 0.0)
points.InsertNextPoint(1.0, 0.0, 0.0)
points.InsertNextPoint(0.0, 1.0, 0.0)
points.InsertNextPoint(1.0, 1.0, 0.0)
grid = vtk.vtkUnstructuredGrid()
grid.SetPoints(points)
grid.InsertNextCell(vtk.VTK_TRIANGLE, 3, [0, 2, 1])
grid.InsertNextCell(vtk.VTK_TRIANGLE, 3, [1, 2, 3])
builder = MatrixBuilder()
data, rows, cols = mass_matrix(grid, [0, 1], parallel=False)
builder.add(data, rows, cols, 1)
assert np.allclose(
builder.build().toarray(),
np.array([
[1 / 12, 1 / 24, 1 / 24, 0],
[1 / 24, 1 / 6, 1 / 12, 1 / 24],
[1 / 24, 1 / 12, 1 / 6, 1 / 24],
[0, 1 / 24, 1 / 24, 1 / 12],
]))
def field_mass_matrix(self, field):
"""Return the mass matrix for a single field."""
# See ramos.utils.vtk.mass_matrix for more info
return mass_matrix(self.dataset(0), self.variates)