Adding C-kernel

[prisae]

C-Kernel

@JanThorbecke and I implemented a C-kernel, simply out of curiosity to compare to the existing Numba Kernel.

Benchmarking has shown that, in the case of empymod, the speed between Numba and C is very comparable. (Different runs will show slightly different results, don't over-interpret the figure.)

To make use of the C-kernel you have to download/clone the repo, checkout the branch c-kernel, and run make install in the root directory. If you then set ht='cdlf' (instead of ht='dlf'), the C-kernel will be used.

• Installation

  git clone [email protected]:emsig/empymod
  cd empymod
  git switch c-kernel
  make install  # or `make dev-install`

• Using in Python

  import empymod
  emfield = empymod.bipole(
      src=...,  # your normal inputs
      rec=...,
      depth=...,
      res=...,
      freqtime=...,
      ht='cdlf',  # Ensure to set ht to 'cdlf'
  )

Please post question and feedback regarding the C-kernel in this PR.

There are still some edge-cases where the C-Kernel produces different results. To test and debug, run, e.g.:

• pytest tests/test_kernel.py
• pytest tests/test_transform.py
• Uncomment lines 16 and 17 in tests/test_model.py and run pytest tests/test_model.py.