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dolfinx
1

Hi all,

In legacy fenics it was possible to reset the index counter by doing

from ufl.core.multiindex import Index
Index._globalcount = 8

However, this doesn’t seem to work in dolfinx.

Is this still the case?

I would like to do:

import dolfinx as dfx
import mpi4py.MPI as mpi
import ufl

mesh = dfx.mesh.create_unit_square(mpi.COMM_WORLD, 10, 10)
V = dfx.fem.FunctionSpace(mesh, ('P', 1))
u = dfx.fem.Function(V)
v = ufl.TestFunction(V)

F1 = ufl.dot(2*ufl.grad(u), ufl.grad(v))*ufl.dx
F2 = ufl.dot(2*ufl.grad(u), ufl.grad(v))*ufl.dx

print(F1)
print(F2)

assert F1.equals(F2)  # this currently fails

Thanks in advance!

2

If I were you, I would try having a look at ufl.algorithms.renumbering.renumber_indices.

3

Good suggestion, as calling

import dolfinx as dfx
import mpi4py.MPI as mpi
import ufl
import ufl.algorithms.renumbering
mesh = dfx.mesh.create_unit_square(mpi.COMM_WORLD, 10, 10)
V = dfx.fem.FunctionSpace(mesh, ('P', 1))
u = dfx.fem.Function(V)
v = ufl.TestFunction(V)

F1 = ufl.dot(2*ufl.grad(u), ufl.grad(v))*ufl.dx
F2 = ufl.dot(2*ufl.grad(u), ufl.grad(v))*ufl.dx

print(F1)
print(F2)
ufl.algorithms.renumbering.renumber_indices(F1).equals( ufl.algorithms.renumbering.renumber_indices(F2))

resolves the issue.

4

Yes this solves the issue thank you very much!