import numpy as np
import pandas as pd

x1 = np.array([1,3,4])
y1 = x1*2
x2 = np.array([1,2,3,4,5,6,7])
y2 = x2*2-1

def test():
    x = np.concatenate((x1,x2))
    y = np.concatenate((y1,y2))
    print len(x),len(y)
    data = pd.DataFrame({'x':x,
			 'y':y})
    data = data.drop_duplicates(subset='x').sort('x',ascending=1)

    return data
