[yt-dev] Issue #1249: annotate_cell_edges: wrong/ugly output for high-resolution data (yt_analysis/yt)

[Dominik Derigs]

New issue 1249: annotate_cell_edges: wrong/ugly output for high-resolution data
https://bitbucket.org/yt_analysis/yt/issues/1249/annotate_cell_edges-wrong-ugly-output-for

Dominik Derigs:

This concerns the functionality added in issue #1198 (annotate_cell_edges). As can be seen in the picture, the routine produces wrong outputs for sufficiently refined data sets:
![windtunnel_4lev_hdf5_plt_cnt_0040_Slice_z_density.png](https://bitbucket.org/repo/BXbAb/images/2894998979-windtunnel_4lev_hdf5_plt_cnt_0040_Slice_z_density.png)

MWE to generate this image:

```
#!python

import yt
ds = yt.load("windtunnel_4lev_hdf5_plt_cnt_0040")
slc = yt.SlicePlot(ds, 'z', 'density')
slc.annotate_cell_edges(alpha=0.3,color=(0.0,0.0,0.0))
slc.save()
```


Data taken from: http://yt-project.org/data/WindTunnel.tar.gz

If I change the resolution of the generated fixed resolution buffer in yt/visualization/plot_window.py:


```
#!python

class PlotWindow(ImagePlotContainer):
[...]
    def __init__(self, data_source, bounds, buff_size=(800,800), antialias=True,
                 periodic=True, origin='center-window', oblique=False,
                 window_size=8.0, fields=None, fontsize=18, aspect=None,
                 setup=False):
```


from 800 to a higher value the result changes, but still it is not satisfactory. For very high resolutions, the results become worse again.

800x800:
![windtunnel_4lev_hdf5_plt_cnt_0040_Slice_z_density.png](https://bitbucket.org/repo/BXbAb/images/2894998979-windtunnel_4lev_hdf5_plt_cnt_0040_Slice_z_density.png)

1200x1200:
![windtunnel_4lev_hdf5_plt_cnt_0040_Slice_z_density_1200.png](https://bitbucket.org/repo/BXbAb/images/3484107681-windtunnel_4lev_hdf5_plt_cnt_0040_Slice_z_density_1200.png)

1600x1600:
![windtunnel_4lev_hdf5_plt_cnt_0040_Slice_z_density_1600.png](https://bitbucket.org/repo/BXbAb/images/1966244505-windtunnel_4lev_hdf5_plt_cnt_0040_Slice_z_density_1600.png)

3200x3200:
![windtunnel_4lev_hdf5_plt_cnt_0040_Slice_z_density_3200.png](https://bitbucket.org/repo/BXbAb/images/1115888674-windtunnel_4lev_hdf5_plt_cnt_0040_Slice_z_density_3200.png)

6000x6000:
![windtunnel_4lev_hdf5_plt_cnt_0040_Slice_z_density_6000.png](https://bitbucket.org/repo/BXbAb/images/422764143-windtunnel_4lev_hdf5_plt_cnt_0040_Slice_z_density_6000.png)