interpolation

import numpy
import numpy as np
import scipy as sp
import matplotlib.pyplot as plt
from scipy.interpolate import interp1d


data = numpy.loadtxt('24march2015.txt')


pres = data[:,0]
temp = data[:,2]
points = zip(pres, temp)
points = sorted(points, key=lambda point: point[0])
pres, temp= zip(*points)
xnew = data[:,0]
ynew = sp.interpolate.interp1d(pres, temp, kind= 'linear')(xnew)
print(ynew)
plt.plot(pres, temp, 'o', label = 'Original_data')
plt.plot(xnew, ynew, '-', label = 'Interpolated_data')
plt.legend()
plt.legend(loc='4')
plt.show()