fix DEVSIM

  Hi,

I was very happy when I learned that DEVSIM was integrated into gdsfactory (great work!). I updated it with the command:

pip install gdsfactory --upgrade

and then:

pip install gdsfactory[full]

I noticed that the DEVSIM package was installed: However, the integration with gdsfactory doesn’t works: Also I tried to find some functions into gdsfactory.simulation related with DEVSIM: and I didn’t find any function. Then I deleted and installed gdsfactory (and plugins) and the issues persisted.

Is there something I did wrong? Is there any step in the update that I didn’t do?

_Originally posted by @adophobr in https://github.com/gdsfactory/gdsfactory/discussions/799_

[tcaduser]

The original poster was successfully loading devsim with the gdsfactory[full] package. Their issue was with a gdsfactory module load.

I avoided making the Intel MKL a pip dependency, because Anaconda users would potentially have 2 different MKL installs in the same environment, totaling over a GB in memory.

devsim supports other lapack and blas libraries by setting the DEVSIM_MATH_LIBS environment variable. The solver then switches from the Intel MKL Pardiso direct solver to SuperLU. This may result in numerical differences in the results. I will have an updated release soon, which will automatically search for libopenblas, liblapack, and then libblas if the Intel MKL is not installed.

[tcaduser]

With version 2.3.6 of devsim, it will search:

1. DEVSIM_MATH_LIBS environment variable
2. Intel MKL libraries
3. libopenblas.so:liblapack.so:libblas.so

It will automatically switch from MKL Pardiso to SuperLU direct solver if the MKL libraries are not available.

Please see: https://github.com/devsim/devsim/blob/main/CHANGES.md