# IMPORT MATPLOTLIB FOR PLOTTING AND
# NUMPY FOR NUMERICAL FUNCTIONS
import matplotlib.pyplot as plt
import numpy as np

# OPEN UP A FIGURE
MyFig=plt.figure(figsize=(12,12))

# LOAD THE DATA FROM THE FILE (TWO EXAMPLES)

# this example works for numpy, but you have to
#   be sure to get the columns right
x,y=np.loadtxt('data.dat',usecols=(0,1),unpack=True)

# this example works for astropy, and you can ask
#   for data using column headers
#from astropy.io import ascii
#data=ascii.read('data.dat',header_start=-2,data_start=0)
#x=data['x']
#y=data['y']

# SET UP A MODEL FUNCTION: Ymod = Xmod**2
# xrange=0.1 to 10 in steps of 0.1
xmod=np.arange(0.1,10,0.1)
ymod=xmod**2.0

# MAKE A LINEAR PLOT OF THE DATA AND MODEL
LinPlot=MyFig.add_subplot(211)
LinPlot.set_xlim([0,10])
LinPlot.set_ylim([0,100])
LinPlot.set_xlabel('X [units]')
LinPlot.set_ylabel('Y [units]')
LinPlot.scatter(x,y,marker='o',color='blue')
LinPlot.plot(xmod,ymod,ls=':',color='red')

# MAKE A LOG-LOG PLOT OF THE DATA AND MODEL
LogPlot=MyFig.add_subplot(212)
LogPlot.set_xlim([0,1])
LogPlot.set_ylim([0,2])
LogPlot.set_xlabel('log X [units]')
LogPlot.set_ylabel('log Y [units]')
LogPlot.scatter(np.log10(x),np.log10(y),marker='x',color='blue')
LogPlot.plot(np.log10(xmod),np.log10(ymod),ls=':',color='red')

# SAVE THE FIGURE
MyFig.savefig('MyFig.png')