Dear all,

I’m transitioning my dolfin code to dolfinx and I need to set function values node by node in parallel. The strategy I used in FEniCS is exactly the one in the answer of this past question but I still haven’t figured out a way to transition to dolfinx, especially because I don’t find any function equivalent to `vec.get_local()`

, `veg.set_local()`

and `vec.apply('insert')`

.

The best I manage to get starting from the answer at the link above is the following code, that unfortunately only works in serial:

```
import dolfinx as df
from mpi4py import MPI
from petsc4py import PETSc
import ufl
import numpy as np
mesh = df.mesh.create_unit_square(MPI.COMM_WORLD, 8, 8)
V = df.fem.FunctionSpace(mesh, ('P', 1))
f = df.fem.Function(V, name='f', dtype=np.float64)
dofmap = V.dofmap
X = V.tabulate_dof_coordinates()
visited = []
Map = mesh.topology.index_map(mesh.topology.dim)
num_cells = Map.size_local + Map.num_ghosts # total number of cells
values = []
for cell_idx in range(num_cells):
vertex_glob_idx = mesh.topology.connectivity(mesh.topology.dim,0).links(cell_idx) # np.array
for dof in vertex_glob_idx:
if not dof in visited:
visited.append(dof)
indeces.append(dof)
values.append(sum(X[dof]**2))
f_vec = f.vector
values = np.array(values)
ni = int(len(values))
indeces = np.array(indeces, dtype=np.int32)
f_vec.setValues(indeces, values)
f_vec.assemble()
f_vec.ghostUpdate(addv=PETSc.InsertMode.INSERT, mode=PETSc.ScatterMode.FORWARD)
# f.x.array[:] = f_vec # not necessary
```

I installed dolfinx in a Docker container. I run the code using jupyter lab, then I visualize the function `f`

using `pyvista`

as explained in the available tutorials.

Any idea about how I can modify it to make it work in parallel?

Thanks in advance!