[AstroPy] how to make a sky plot

[Eric Jensen]

On Apr 2, 2014, at 10:10 AM, Jonathan T. Niehof wrote:

> (Don't know if it's possible to label RA in hours 
> instead of degrees longitude.)

If it isn't possible to do this directly in the plotting routine, you could do something like this to manipulate the x-axis tick labels directly.  (But if you do this, don't forget when looking at your plot and modifying your plot code that you are really still plotting a variable in degrees even if your label is in hours!  e.g. your limits would still have to be degrees ) 

fig = plt.figure()
ax = fig.add_subplot(111)

[ Code in here to plot your data and set axis limits. ]

# Need to draw the canvas in order for ticklabels to be set:
fig.canvas.draw()
ticklist= ax.get_xticklabels()
new_label_list = []
for label in ticklist:
    # Get rid of dollar signs if using Latex labels: 
    string= label.get_text().replace('$', '')
    # Some labels may be blank, leave as-is:
    if string == '':
        new_label = string
    else: 
	# Get numeric equivalent, change to hours:
        tick_num = float(string)
        tick_num = tick_num/15.
	# Note that this rounds to integer, might not be what you want:
        tick_string = "%d" % tick_num
	# Add a raised "h" to denote hours:
        new_label = "$" + tick_string + "^h$"
    new_label_list.append(new_label)
new = ax.set_xticklabels(new_label_list)

(Based on code from http://stackoverflow.com/questions/11244514/matplotlib-modify-tick-label-text )
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