# Dof transformations not supported by bempp-cl

**URL:** <https://bempp.discourse.group/t/dof-transformations-not-supported-by-bempp-cl/250>\
**Category:** Bempp\
**Created:** [14 March 2024 12:29 UTC](https://bempp.discourse.group/t/dof-transformations-not-supported-by-bempp-cl/250 "2024-03-14T12:29:05Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Gabriel](https://avatars.discourse-cdn.com/v4/letter/g/9de0a6/32.png) [@Gabriel](https://bempp.discourse.group/u/Gabriel)\
**Post date:** [14 March 2024 12:29 UTC](https://bempp.discourse.group/t/dof-transformations-not-supported-by-bempp-cl/250/1 "2024-03-14T12:29:05Z")

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Hello,  
I am concerned with Maxwell problems and was very impressed by BEMpp capabilities described in the Scroggs & al. 2017 paper ([Redirecting](http://dx.doi.org/10.1016/j.camwa.2017.07.049)). The tutorials maxwell\_dielectric and maxwell\_screen in Jupyter notebooks are also very convenient and impressive. However, the bempp-cl version I installed appears to be more limited that the one used to write the 2017 paper. For example, only magnetic field boundary operators with RWG domain and SNC dual can be generated. When RBC is selected for dual (which can be appealing…), the following error arises:

> Blockquote

“Spaces that require dof transformations not supported for dense assembly.”

> Blockquote

Is there some way to circumvent this issue?  
Thanks,  
Gabriel

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<div class="post-metadata">

**Author:** ![Mario](https://avatars.discourse-cdn.com/v4/letter/m/8e7dd6/32.png) [@Mario](https://bempp.discourse.group/u/Mario)\
**Post date:** [29 October 2024 14:22 UTC](https://bempp.discourse.group/t/dof-transformations-not-supported-by-bempp-cl/250/2 "2024-10-29T14:22:56Z")

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Hi, I am also very interested in being able to circumvent this limitation; I am trying to assemble the magnetic field boundary operator as:

bempp.api.operators.boundary.maxwell.magnetic\_field(  
rwg\_space, rwg\_space, rbc\_space, waveNumber, assembler=‘dense’,  
precision=‘double’, device\_interface=‘opencl’)

When I try to solve the problem (identity+mfie) via the LU decomposition, I get the same error:  
Spaces that require dof transformations not supported for dense assembly.

Thanks in advance!