# How to obtain dofs of FunctionSpace in dolfinx?

**URL:** <https://fenicsproject.discourse.group/t/how-to-obtain-dofs-of-functionspace-in-dolfinx/7090>\
**Category:** dolfinx\
**Created:** [November 15, 2021, 4:26pm UTC](https://fenicsproject.discourse.group/t/how-to-obtain-dofs-of-functionspace-in-dolfinx/7090 "2021-11-15T16:26:05Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![dokken](https://yyz2.discourse-cdn.com/free1/user_avatar/fenicsproject.discourse.group/dokken/32/1560_2.png) [@dokken](https://fenicsproject.discourse.group/u/dokken)\
**Post date:** [November 15, 2021, 5:03pm UTC](https://fenicsproject.discourse.group/t/how-to-obtain-dofs-of-functionspace-in-dolfinx/7090/2 "2021-11-15T17:03:41Z")

</div>

Consider:

```python
import dolfinx
from mpi4py.MPI import COMM_WORLD
mesh=dolfinx.UnitSquareMesh(COMM_WORLD,2,2)
import ufl
FE=ufl.FiniteElement("Lagrange",mesh.ufl_cell(),1)
V=dolfinx.FunctionSpace(mesh,FE)

num_dofs_local = (V.dofmap.index_map.size_local) * V.dofmap.index_map_bs
num_dofs_global = V.dofmap.index_map.size_global * V.dofmap.index_map_bs

print(f"Number of dofs (owned) by rank {COMM_WORLD.rank}: {num_dofs_local}")
if COMM_WORLD.rank ==0:
    print(f"Number of dofs global: {num_dofs_global}")

```

Yielding:

```bash
root@81aa206a058d:~/shared# mpirun -n 1 python3 num_dofs.py 
Number of dofs (owned) by rank 0: 9
Number of dofs global: 9

root@81aa206a058d:~/shared# mpirun -n 2 python3 num_dofs.py 
Number of dofs (owned) by rank 0: 6
Number of dofs global: 9
Number of dofs (owned) by rank 1: 3
```

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