Set integration rule to closed/vertex

General
5

I encountered the same problem for boundary integrals. Here is a MWE:

from dolfinx import mesh, fem
import ufl
from mpi4py import MPI
import numpy as np

N = 1
domain = mesh.create_unit_square(MPI.COMM_WORLD, N, N)
V = fem.FunctionSpace(domain, ("CG", 1))
v = ufl.TestFunction(V)

x = ufl.SpatialCoordinate(domain)

ds = ufl.Measure(
        "ds",
        metadata={
            #"quadrature_rule":"vertex",
            "quadrature_rule":"custom",
            "quadrature_points":np.array([[0.0], [1.0]]),
            "quadrature_weights":np.array([1.0 / 2.0, 1.0 / 2.0]),
            }
        )

b = x[0]*v*ds

linear_form   = fem.form( b )

b = fem.petsc.create_vector(linear_form)
fem.petsc.assemble_vector(b, linear_form)

print( "b = \n", b.getValues( range(b.size) ) )

Uncommenting the vertex quadrature rule line and commenting the custom quadrature rules lines gives an AssertionError. I am working with the nightly version.