# Working with different subdomains: from meshio to dolfin

**URL:** <https://fenicsproject.discourse.group/t/working-with-different-subdomains-from-meshio-to-dolfin/5066>\
**Category:** mesh\
**Created:** [February 10, 2021, 11:00am UTC](https://fenicsproject.discourse.group/t/working-with-different-subdomains-from-meshio-to-dolfin/5066 "2021-02-10T11:00:56Z")\
**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:** [February 10, 2021, 12:07pm UTC](https://fenicsproject.discourse.group/t/working-with-different-subdomains-from-meshio-to-dolfin/5066/2 "2021-02-10T12:07:08Z")

</div>

Please mark the Physical Surface and Curve with numbers, not strings. As you can observe by inspecting the `boundary.xdmf` file the values on each boundary is not 1 and 2, but 2 and 3, and does not consist of the whole circle.  
This is because you are converting all the data written in with meshio.  
See for instance: [Transitioning from mesh.xml to mesh.xdmf, from dolfin-convert to meshio - #104 by dokken](https://fenicsproject.discourse.group/t/transitioning-from-mesh-xml-to-mesh-xdmf-from-dolfin-convert-to-meshio/412/104)  
or [Mesh generation and conversion with GMSH and PYGMSH | Jørgen S. Dokken](https://jsdokken.com/converted_files/tutorial_pygmsh.html#second)  
for how to convert a meshio mesh and corresponding boundary data in a safe way.

---

_[View the full topic](https://fenicsproject.discourse.group/t/working-with-different-subdomains-from-meshio-to-dolfin/5066)._