# Evaluate\_basis\_all in dolfinx
**URL:** https://fenicsproject.discourse.group/t/evaluate-basis-all-in-dolfinx/3968
**Category:** dolfinx
**Created:** [August 20, 2020, 8:15am UTC](https://fenicsproject.discourse.group/t/evaluate-basis-all-in-dolfinx/3968 "2020-08-20T08:15:15Z")
**Posts on this page:** 4
**Page:** 2
### Author:  [@Xijan](https://fenicsproject.discourse.group/u/Xijan)
#### Post date: [March 25, 2024, 2:26am UTC](https://fenicsproject.discourse.group/t/evaluate-basis-all-in-dolfinx/3968/21 "2024-03-25T02:26:33Z")
How can I convert it to new Dolfinx Fenicsx?
---
### Author:  [@dokken](https://fenicsproject.discourse.group/u/dokken)
#### Post date: [March 25, 2024, 3:23am UTC](https://fenicsproject.discourse.group/t/evaluate-basis-all-in-dolfinx/3968/22 "2024-03-25T03:23:08Z")
Without writing what error you are getting with the code above, and what version of FEniCSx you are using, it is unlikely that you will get an answer to this question.
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### Author:  [@Xijan](https://fenicsproject.discourse.group/u/Xijan)
#### Post date: [March 25, 2024, 3:40am UTC](https://fenicsproject.discourse.group/t/evaluate-basis-all-in-dolfinx/3968/23 "2024-03-25T03:40:15Z")
## Thank you. Error is:
TypeError Traceback (most recent call last)
Cell In[105], line 10
7 V = dolfinx.fem.FunctionSpace(domain, (“CG”, 2))
9 point = np.array([[0.2, 0.3, 0]])
—\> 10 bb = dolfinx.geometry.BoundingBoxTree(domain, tdim)
11 bbox\_collisions = dolfinx.geometry.compute\_collisions(bb, point)
12 cells = dolfinx.geometry.compute\_colliding\_cells(domain, bbox\_collisions, point)
TypeError: BoundingBoxTree. **init** () takes 2 positional arguments but 3 were given
I am using Dolfinx 0.8 and Fenicsx 0.7
---
### Author:  [@dokken](https://fenicsproject.discourse.group/u/dokken)
#### Post date: [March 25, 2024, 7:28am UTC](https://fenicsproject.discourse.group/t/evaluate-basis-all-in-dolfinx/3968/24 "2024-03-25T07:28:24Z")
Please note that your specification of versions doesn’t make sense, as
> [@Xijan](#):
>
> I am using Dolfinx 0.8 and Fenicsx 0.7
DOLFINx and FEniCSx represents the same package.
Here is an updated example for v0.7.x
```python
from mpi4py import MPI
import dolfinx
import ufl
import numpy as np
domain = dolfinx.mesh.create_unit_square(MPI.COMM_WORLD, 1, 1)
tdim = domain.topology.dim
V = dolfinx.fem.FunctionSpace(domain, ("CG", 2))
point = np.array([[0.2, 0.3, 0]])
bb = dolfinx.geometry.bb_tree(domain, tdim)
bbox_collisions = dolfinx.geometry.compute_collisions_points(bb, point)
cells = dolfinx.geometry.compute_colliding_cells(
domain, bbox_collisions, point)
cell = cells.links(0)[0]
cmap = domain.geometry.cmaps[0]
geom_dofs = domain.geometry.dofmap[cell]
x_ref = cmap.pull_back(point, domain.geometry.x[geom_dofs])
n = ufl.as_vector([0.1, 0.2])
expr = ufl.inner(ufl.grad(ufl.TestFunction(V)), n)
E = dolfinx.fem.Expression(expr, x_ref)
grad_u_at_x_ref = E.eval(domain, [cell])
print(
f"Cell: {cell}, Point: {point}, x_ref: {x_ref}, grad(u)*n {grad_u_at_x_ref}")
```
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