[yt-dev] Issue #1143: Sphere callback for OffAxisProjectionPlot does not do coordinate conversions correctly (yt_analysis/yt)

[Nathan Goldbaum]

New issue 1143: Sphere callback for OffAxisProjectionPlot does not do coordinate conversions correctly
https://bitbucket.org/yt_analysis/yt/issues/1143/sphere-callback-for-offaxisprojectionplot

Nathan Goldbaum:

The following test script:


```
#!python

import yt

ds = yt.load('IsolatedGalaxy/galaxy0030/galaxy0030')

plot = yt.OffAxisProjectionPlot(ds, [0, 0, 1], 'density')

plot.annotate_sphere([0, 0, 0], (300, 'kpc'))
```

Produces the following image:

![download.png](https://bitbucket.org/repo/BXbAb/images/2406981540-download.png)

This is wrong, the circle should be centered on the origin.