# Compute Cell Coordinates and Cell\_Jacobian dolfinx through ufl form

**URL:** <https://fenicsproject.discourse.group/t/compute-cell-coordinates-and-cell-jacobian-dolfinx-through-ufl-form/14047>\
**Category:** dolfinx\
**Created:** [March 27, 2024, 10:36pm UTC](https://fenicsproject.discourse.group/t/compute-cell-coordinates-and-cell-jacobian-dolfinx-through-ufl-form/14047 "2024-03-27T22:36:27Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![bagla0](https://yyz2.discourse-cdn.com/free1/user_avatar/fenicsproject.discourse.group/bagla0/32/4677_2.png) [@bagla0](https://fenicsproject.discourse.group/u/bagla0)\
**Post date:** [March 27, 2024, 10:36pm UTC](https://fenicsproject.discourse.group/t/compute-cell-coordinates-and-cell-jacobian-dolfinx-through-ufl-form/14047/1 "2024-03-27T22:36:27Z")

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I have a general query in dolfinx. For each cell, I want to compute

1. Cell\_Jacobian (`Jacobian(mesh)` is not evaluated for each cell)
2. cell coordinates

I wanted to make a vector using cell origin and midpoint of cell facet for each element and interpolating the vector to a ufl form. How can I approach for a simple unit square mesh?  
With this I want to make a local orthogonal frame for each element using 2 in-plane vectors and 1 normal vector (through Jacobian).  
Any help is appreciated!

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**Author:** ![bleyerj](https://yyz2.discourse-cdn.com/free1/user_avatar/fenicsproject.discourse.group/bleyerj/32/6020_2.png) [@bleyerj](https://fenicsproject.discourse.group/u/bleyerj)\
**Post date:** [March 29, 2024, 10:11am UTC](https://fenicsproject.discourse.group/t/compute-cell-coordinates-and-cell-jacobian-dolfinx-through-ufl-form/14047/2 "2024-03-29T10:11:06Z")

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This should help you  
[https://bleyerj.github.io/comet-fenicsx/tours/shells/linear\_shell/linear\_shell.html#computing-a-local-tangent-frame](https://bleyerj.github.io/comet-fenicsx/tours/shells/linear_shell/linear_shell.html#computing-a-local-tangent-frame)