Dieter Werthmüller

#185 introduced more flexible definitions for the `x`/`y`-coordinates of dipoles (`dipole`, `dipole_k`, `analytical`). This PR implements more flexibility for the definition of sources and receivers in bipoles (`bipole`, `loop`). Namely,...

A `empymod-plain`-release was introduced in `v2.2.1`, marked as `v2.2.1.post1`; it lives in the branch `plain`. This is only available on pip, mainly meant for micropip for things like JupyterLite etc....

Add convenience functions/classes and examples how to run inversions with, e.g., [pyGIMLi](https://www.pygimli.org) or [SimPEG](https://simpeg.xyz). See [Inversion Milestone](https://github.com/emsig/emg3d/milestone/2) => [invDev](https://github.com/emsig/devInv)

After a fresh install, the `GPR_Attenuation.ipynb` failed because it was missing `pip install em_examples`. I would have added it to the yml-file, but I am not sure if you just...

In the following table https://em.geosci.xyz/content/maxwell1_fundamentals/harmonic_planewaves_homogeneous/skindepth.html#skin-depth-for-various-materials the conductivity of air is given as 0 S/m, which results in an infinite skin depth, suggesting that an EM signal travels the whole globe...

hotfix to make it NOT fail due to `np.long`-Error on MyBinder.

`em_examples` is not in the environment.yml, so the following notebook fails and needs installation of `em_examples`: `http://localhost:8889/notebooks/notebooks/GPR_Attenuation.ipynb`

### `TDEM_UXO.ipynb` After installing cvxopt in Python 3.7, the UXO-notebook still fails with the following error: ``` --------------------------------------------------------------------------- TypeError Traceback (most recent call last) ~/anaconda3/lib/python3.7/site-packages/ipywidgets/widgets/interaction.py in update(self, *args) 254 value...

The link `TDEM_Inductivesource.ipynb` in the `index.ipynb` ends up in a `404 : Not Found` error.

`geoscilabs` is not in the environment, I had to install it additionally. It would throw an error in at least the following notebooks (maybe in more): - TDEM_HorizontalLoop_Sphere.ipynb - FDEM_VMD_Sphere.ipynb...