New issue 1035: defining a bounding box causes units problems in tipsy data sets https://bitbucket.org/yt_analysis/yt/issue/1035/defining-a-bounding-box-caus...

Desika Narayanan:

Hey All,

FYI, this may be related to [PR # 1524](https://bitbucket.org/yt_analysis/yt/pull-request/1524/added-functionality-f...)

If I run the following on the tipsy data set:

``` import yt import numpy as np

fname = 'TipsyGalaxy/galaxy.00300'

boxsize = 100 bbox = [[-boxsize,boxsize], [-boxsize,boxsize], [-boxsize,boxsize]]

ds = yt.load(fname,bounding_box=bbox) ds.index

px = yt.ProjectionPlot(ds,"z",('deposit', 'Gas_density'),center='m') px.save('junk.z.png') ```

I'll get an image back out that has the galaxy as 50 cm big! However, if I run the same code but replace the load command with:

``` ds = yt.load(fname) ```

then no problem.

Another way this manifests itself is if I load with the bounding_box set in the load command, then:

``` In [11]: ds.length_unit Out[11]: 1.0 kpc

In [12]: ds.domain_left_edge Out[12]: YTArray([-100., -100., -100.]) code_length

In [13]: ds.domain_left_edge.in_units('kpc') Out[13]: YTArray([ -3.24077929e-20, -3.24077929e-20, -3.24077929e-20]) kpc ```

I've looked through frontends/tipsy/data_structures and can't seem to figure what's doing this.

Again, this might not be related to this PR, but it sure seems similar.