[yt-dev] Issue #753: SlicePlot differences from 2.x to 3.0 (yt_analysis/yt)

[Cameron Hummels]

New issue 753: SlicePlot differences from 2.x to 3.0
https://bitbucket.org/yt_analysis/yt/issue/753/sliceplot-differences-from-2x-to-30

Cameron Hummels:

I have a small 2D dataset from an enzo KH test (64^2 dataset): http://www.astro.columbia.edu/~chummels/DD0010.tar

I take a SlicePlot of it using this simple script:
http://paste.yt-project.org/show/4157/

When I do this in yt 2.6 dev (changeset 6bffc737a67a), I get this image:
http://i.imgur.com/nfGs13M.png

When I do this in yt 3.0 vanilla (changeset: 7026b9ddfc20), I get this image:
http://i.imgur.com/va2c9TF.png

When I do this in yt 3.0 unitrefactor (changeset: a26e91190d0e), I get this image:
http://i.imgur.com/SfRb5AW.png

The most obvious change is that the axes are flipped between the 2.x and 3.0 renderings.  The 2.x renderings are correct in that the stratification of the fluids should be in the y direction, not the x direction.

The second obvious change is in units.  Note again, the 2.x units are correct in that this is a 1x1 area in code units, which it displays as having axes length 1cmx1cm.  The vanilla 3.0 units are the same as the 2.x units.  The 3.0 unitsrefactor axis length units are seemingly scaled by some constant that applies in cosmological runs, because instead of being 1cm x 1cm, they are now ~7e10 x 7e10 solar radii in size.

Perhaps this is just a change for 2D datasets, but I figure it is worth looking into for everything.