from matplotlib import pylab as pl
import numpy as np

t, ezp, ehm, lp = np.loadtxt('thermal-expansion-data.txt',unpack=True)

fig = pl.figure()
enerax = fig.add_subplot(2,1,1)
enerax.set_ylabel("Helmholtz Free Energy/ eV")
enerax.set_xlabel("Temperature/ K")
lattax = fig.add_subplot(2,1,2)
lattax.set_ylabel("Lattice Parameter/ Angstroms")
lattax.set_xlabel("Temperature/ K")

pl.subplots_adjust(hspace = 0.5)

enerax.plot(t, ehm,color='red')
lattax.plot(t, lp,color='green')
pl.show()