Hi,

This might be a very simple question but can’t find an easy solution to it. Suppose I have a point which lies strictly inside of a mesh cell.

1- What is the fastest way to extract the ID and vertices of that cell?

2- What if that point is exactly a mesh point? Which cell ID will I get as the answer?

Here is a minimal code with a mesh and the x,y,z coordinates of a point which I am sure lies strictly inside of a cell. How can I answer the above questions for this code?

```
from dolfin import *
meshlevel =10
degree = 1
dim = 2
mesh = UnitDiscMesh.create(MPI.comm_world,meshlevel, degree, dim)
Px = -0.519
Py = 0.33
Pz = 0.0
```