show_lines has no color by default

[keflavich]

Noted in aplpy/aplpy-examples#1, apparently show_lines defaults to no color. There is no obvious reason for this that I can see in the source for show_lines or LineCollection:

F.show_grayscale()
F.show_lines([np.array([[265,267],[-28,-30]])]) # shows nothing
F.show_lines([np.array([[265,267],[-28,-30]])],color='r')

[neuronphysics]

In the input list of arrays of show_lines() do you provide the first component of np.array as all the right ascensions and the second one the declinations? because I got confused with the order of input file with this example!

[keflavich]

@neuronphysics: Your question isn't relevant to this issue, so could you please post it on the astropy examples page instead? Yes, the order is always ra,dec

[gully]

I love open source. I was at wit's end to help a graduate student who asked me why show_lines( wasn't working, I typed that substring into GitHub search and voilà: answer is here.
So I guess thank you all for contributing to open source and making this dialog public to help others. Although the default of no color seems like a bug, right?

[keflavich]

@gully yes, I think this is fair to regard as a bug. The user should either be warned that no color is selected or there should be a default color. A pull request fixing the issue would be welcome.