show_rectangles rotated with respect to corner, not with respect to center.

[leungcalvin]

Hi! I noticed a small bug in show_rectangles as follows:

Since in show_rectangles the coordinates are those of the rectangle's center, I thought that rotations (with the angle keyword) would also be about the rectangle's center. I tried to do this with

show_rectangles(self=zoom_out_fig,
                         xw = gal_ra, 
                         yw = gal_dec, 
                         width = 1.5/60/60, 
                         height = 10/60/60, angle=0, 
                         layer=False, 
                         zorder=None, 
                         coords_frame='world',
                         edgecolor='white')
show_rectangles(self=zoom_out_fig,
                         xw = gal_ra, 
                         yw = gal_dec, 
                         width = 1.5/60/60, 
                         height = 10/60/60, angle=10, 
                         layer=False, 
                         zorder=None, 
                         coords_frame='world',
                         edgecolor='white')
show_rectangles(self=zoom_out_fig,
                         xw = gal_ra, 
                         yw = gal_dec, 
                         width = 1.5/60/60, 
                         height = 10/60/60, angle=-10, 
                         layer=False, 
                         zorder=None, 
                         coords_frame='world',
                         edgecolor='white')

but I get

A quick fix is to modify show_rectangle:

aplpy/aplpy/core.py

Line 1434 in 2634350

x = x - w / 2.

and to change that line to the following:

    x = x - (w / 2 * np.cos(a*np.pi/180) - h / 2 * np.sin(a*np.pi/180))
    y = y - (w / 2 * np.sin(a*np.pi/180) + h / 2 * np.cos(a*np.pi/180))

which gave me what I (and maybe other naive users like myself) expected.

[Sullofect]

Encounter same thing! Thanks for your edition!