[AstroPy] Grid lines on FITS images

[Demitri Muna]

Hi,

On Jun 1, 2015, at 12:20 PM, Thomas Robitaille <thomas.robitaille at gmail.com> wrote:

> I think that WCSAxes (http://wcsaxes.readthedocs.org <http://wcsaxes.readthedocs.org/>) will do what you
> need? Let me know if you have any issues using it.


Thanks Tom. I went through the documentation/tutorial and created a sample script. It doesn't do exactly what I'm looking for - as far as I can tell. I'm using matplotlib.patches.Polygon to define my polygon, supplying a world transform based on the FITS header.

I don't know how the underlying drawing mechanism works. If it is taking the world coordinates that I apply, e.g. the four corners of a polygon, converting them to pixel coordinates, and then drawing straight lines on the canvas between them, then they are not proper representations as they are not following great circles. If the transform is applied to each pixel drawn, then it might be. My (pure) guess is that it's doing the former. (I would like to test this, but that will have to wait until after SciCoder.)

I think in the end PyAST will do what I need, but I may still use parts of WSCAxes.

Thanks,
Demitri

_________________________________________
Demitri Muna

Department of Astronomy
Ohio State University

http://trillianverse.org
http://scicoder.org



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