Some velocity field examples [WIP]

[The9Cat]

Three examples:

1. Using the halo-disk EXP example
2. Using a pure halo with a quadrupole bar
3. Unstable Zang disk

All of these could use some tuning.

[The9Cat]

In halo bar.ipynb, one needs to get to N=10,000,000 particles to get nice fields. This is, in part, because I need R_max=4 to suppress the NFW l=1 halo mode so there are too few particles in the bar region. But, when one gets to these high values, it looks very nice!

I would propose that we add the coefficient files for this example without running the simulation as part of the example.

[The9Cat]

I had to remove cell content from zang disk vel to reduce the size to meet github constraints, alas.

[The9Cat]

Recent updates include

• Minor improvements in documentation
• Debug testing stuff removed
• Original notebooks tested against latest PR, Minor updates to field coefficient bases and OutVel EXP#143
• Added a new notebook that exercises both disk and halo velocity fields using a precomputed set of coefficients. Might want to ditch the halo fields; except for density, they are not all that revealing, although they do provide an example of doing it...

To Do

• More testing
• The new notebook could be moved to Tutorials/Coefficients from Tutorials/EXP since an exp run is not part of the workflow but it seems to below with the others
• More examples?
• Once we are happy with these updates/changes, we need to make the navigation footers consistent with the tutorial 'course' ordering