gistfile1.py

import random
def plot_correspondence(points1, points2, fraction_of_lines):
    fig,(ax1,ax2) = subplots(1,2,sharex=True,sharey=True,figsize=(10,8)) 
    # Set plot boundaries
    ax1.set_ylim(31,43)
    ax1.set_xlim(-126,-112)
    # Draw first points
    ax1.scatter(points1[:,0],points1[:,1],s=0.5,color='b') 
    # Draw second points
    ax2.scatter(points2[:,0],points2[:,1],s=0.5,color='r') 

    # Draw correspondence lines
    which_lines = random.sample(xrange(len(points1)), int(fraction_of_lines*len(points1)))
    for ((x1,y1),(x2,y2)) in zip(points1[which_lines], points2[which_lines]):
        ax2.plot([x1, x2], [y1, y2], 'black',alpha=0.3)

    return fig 




# Example
points1 = np.random.randn(100,2) + np.array([-120,36])
points2 = points1+0.5*np.random.randn(100,2)
fig=plot_correspondence(points1,points2, 1)
fig.savefig("/tmp/test.png",dpi=300)