[yt-dev] Issue #1320: Annotating halos fails in yt-3.3.4 (yt_analysis/yt)

[Kacper Kowalik]

New issue 1320: Annotating halos fails in yt-3.3.4
https://bitbucket.org/yt_analysis/yt/issues/1320/annotating-halos-fails-in-yt-334

Kacper Kowalik:

Following code:

```
#!python

import yt
from yt.analysis_modules.halo_analysis.halo_catalog import HaloCatalog

data_ds = yt.load('Enzo_64/RD0006/RedshiftOutput0006')
halos_ds = yt.load('rockstar_halos/halos_0.0.bin')

hc = HaloCatalog(halos_ds=halos_ds)
hc.create()

prj = yt.ProjectionPlot(data_ds, 'z', 'density')
prj.annotate_halos(hc, annotate_field='particle_identifier')
prj.save()
```

yields:

```
#!bash
Traceback (most recent call last):
  File "yt/visualization/plot_window.py", line 1007, in run_callbacks
    callback(cbw)
  File "yt/visualization/plot_modifications.py", line 54, in _check_geometry
    return func(self, plot)
  File "yt/visualization/plot_modifications.py", line 1473, in __call__
    radius = halo_data[self.radius_field][:].in_units(units)
AttributeError: 'HaloCatalogCallback' object has no attribute 'radius_field'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "foo.py", line 12, in <module>
    prj.save()
  File "yt/visualization/plot_container.py", line 78, in newfunc
    args[0]._setup_plots()
  File "yt/visualization/plot_window.py", line 956, in _setup_plots
    self.run_callbacks()
  File "yt/visualization/plot_window.py", line 1013, in run_callbacks
    sys.exc_info()[2])
  File "six.py", line 685, in reraise
    raise value.with_traceback(tb)
  File "yt/visualization/plot_window.py", line 1007, in run_callbacks
    callback(cbw)
  File "yt/visualization/plot_modifications.py", line 54, in _check_geometry
    return func(self, plot)
  File "yt/visualization/plot_modifications.py", line 1473, in __call__
    radius = halo_data[self.radius_field][:].in_units(units)
yt.utilities.exceptions.YTPlotCallbackError: annotate_halos callback failed with the following error: 'HaloCatalogCallback' object has no attribute 'radius_field'
```