New issue 839: AMRKDTree.count_cells() fails with a YTUnitOperationError
https://bitbucket.org/yt_analysis/yt/issue/839/amrkdtreecount_cells-fails...
Stuart Mumford:
running `amrkdtree_downsampling.py` produces the following:
```
#!python
Traceback (most recent call last):
File "/home/stuart/BitBucket/yt/doc/source/cookbook/amrkdtree_downsampling.py", line 19, in <module>
print kd.count_cells()
File "/home/stuart/BitBucket/yt/yt/utilities/amr_kdtree/amr_kdtree.py", line 537, in count_cells
return self.tree.sum_cells()
File "/home/stuart/BitBucket/yt/yt/utilities/amr_kdtree/amr_kdtree.py", line 124, in sum_cells
li = np.rint((nle-gle)/dds).astype('int32')
File "/home/stuart/BitBucket/yt/yt/units/yt_array.py", line 496, in __rsub__
lo = sanitize_units_add(self, left_object, "subtraction")
File "/home/stuart/BitBucket/yt/yt/units/yt_array.py", line 141, in sanitize_units_add
dimensionless)
yt.utilities.exceptions.YTUnitOperationError: The subtraction operator for YTArrays with units (code_length) and (1) is not well defined.
```
New issue 838: OffAxisSlicePlot dosen't respect the unit of width
https://bitbucket.org/yt_analysis/yt/issue/838/offaxissliceplot-dosent-re...
Stuart Mumford:
I tried to run the `aligned_cutting_plane.py` from the cook book and changing:
```
#!python
p = yt.OffAxisSlicePlot(ds, L, "density", sp.center, (25, "kpc"))
```
to
```
#!python
p = yt.OffAxisSlicePlot(ds, L, "density", sp.center, (25, "pc"))
```
only resulted in the axis label changing not the view on the data.
