Matplotlib: Adjust legend location/position

Question

I\'m creating a figure with multiple subplots. One of these subplots is giving me some trouble, as none of the axes corners or centers are free (or can be freed up) for placing

Answer 1

After spending way too much time on this, I've come up with the following satisfactory solution (the Transformations Tutorial definitely helped):

bapad = plt.rcParams['legend.borderaxespad']
fontsize = plt.rcParams['font.size']
axline = plt.rcParams['axes.linewidth']  #need this, otherwise the result will be off by a few pixels
pad_points = bapad*fontsize + axline  #padding is defined in relative to font size
pad_inches = pad_points/72.0  #convert from points to inches
pad_pixels = pad_inches*fig.dpi  #convert from inches to pixels using the figure's dpi

Then, I found that both of the following work and give the same value for the padding:

# Define inverse transform, transforms display coordinates (pixels) to axes coordinates
inv = ax[1].transAxes.inverted()
# Inverse transform two points on the display and find the relative distance
pad_axes = inv.transform((pad_pixels, 0)) - inv.transform((0,0))  
pad_xaxis = pad_axes[0]

or

# Find how may pixels there are on the x-axis
x_pixels = ax[1].transAxes.transform((1,0)) - ax[1].transAxes.transform((0,0))
# Compute the ratio between the pixel offset and the total amount of pixels 
pad_xaxis = pad_pixels/x_pixels[0]

And then set the legend with:

ax[1].legend(loc=(pad_xaxis,0.6))

Plot: