fit_annuli: plots=None renders all panels (can't disable via None) and leaks Matplotlib figures in loops

Start in eddy/rotationmap.py at fit_annuli around line 534, then inspect plot_velocity_profiles, plot_model, and plot_model_residual around the referenced plotting code. Run the 30-call reproduction and compare plots=None, plots=[], and the documented options. Done means the plots argument behavior, figure lifecycle, and docstring agree without accumulating open figures.

Summary

In rotationmap.fit_annuli, the plots argument defaults to None, but None is
interpreted as "plot all panels" rather than "plot nothing". To suppress plotting you
have to pass plots=[], which is neither documented nor obvious. Because the plotting
helpers open figures without closing them, calling fit_annuli in a loop (e.g. a
Monte-Carlo over many maps) leaks a figure per call — triggering matplotlib's
More than 20 figures have been opened warning and growing memory unbounded.

Version

eddy 3.1.0, eddy/rotationmap.py.

Where

# eddy/rotationmap.py, fit_annuli, ~L534
plots = ['profiles', 'model', 'residual'] if plots is None else plots
plots = np.atleast_1d(plots)
if 'profiles' in plots:
    self.plot_velocity_profiles(rpnts=rpnts, velo=velo, dvelo=dvelo)
if 'model' in plots:
    self.plot_model(model=model)
if 'residual' in plots:
    self.plot_model_residual(model=model)

Each of plot_velocity_profiles / plot_model / plot_model_residual does
fig, ax = plt.subplots() (e.g. rotationmap.py:2321) and never closes the figure.

Reproduce

import matplotlib.pyplot as plt
# rmap = some rotationmap / momentmap with a fittable map
for i in range(30):
    rmap.fit_annuli(x0=0, y0=0, inc=inc, PA=PA, rbins=rbins,
                    fit_vrad=True, fix_vlsr=vlsr, returns='residual')  # plots=None
print(len(plt.get_fignums()))   # ~90 open figures (3 per call); RuntimeWarning fires at 20

Expected vs. actual

• Expected: plots=None (the default) produces no plots — the conventional meaning of
  an optional plots/plot kwarg — and repeated calls do not accumulate figures.
• Actual: plots=None renders all three panels every call, and the figures are never
  closed, so a loop leaks figures and eventually warns / risks OOM.

Secondary: docstring mismatch

The docstring says:

plots (Optional[list]): Plots to generate after the fitting. Can be either of 'model'
and 'residual'. Default is both.

But the code default is three panels including 'profiles', and 'profiles' is a
valid (undocumented) option.

Suggested fix (your call)

• Treat a falsy plots (None / [] / False) as no plots; if plot-by-default is
  wanted, use an explicit default list instead of the None sentinel.
• Close the figures after drawing (or return them) so loop callers don't leak — or gate
  plotting behind an explicit plot=True.
• Update the docstring to list 'profiles' and state the actual default.

Workaround

Pass plots=[] to suppress plotting.