# Databased nonlinear coefficients

**URL:** <https://community.freefem.org/t/databased-nonlinear-coefficients/3626>\
**Category:** General Discussion\
**Created:** [December 14, 2024, 2:18pm UTC](https://community.freefem.org/t/databased-nonlinear-coefficients/3626 "2024-12-14T14:18:12Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Phuang](https://avatars.discourse-cdn.com/v4/letter/p/b782af/32.png) [@Phuang](https://community.freefem.org/u/Phuang)\
**Post date:** [December 14, 2024, 2:18pm UTC](https://community.freefem.org/t/databased-nonlinear-coefficients/3626/1 "2024-12-14T14:18:12Z")

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Hi, I am exploring the possibilities to use FreeFem to solve electromagnetic problem using the test date for coefficients. Specifically, I have test data for magnetic permeability /mu which depends on the solution. I searched other examples in FreeFEM but they all assume constant /mu. Does anyone try anything similar? Here is a simplified equation:

Curl( curl(A)/mu) =0

Where my is a table depending on absolute value of curl(A)

Thanks