Using matplotllib to plot

plot.py

import matplotlib
# if your environment has no desktop.
matplotlib.use('Agg')
import matplotlib.pyplot as plt

# A scatter map.
plt.figure(figsize=(width,height))
plt.scatter(x,y)
plt.show
plt.savefig('scatter.png')


# A hist map
n, bins, patches = plt.hist(x,bins=10,range=None,normed=False, normed=1, facecolor='g', alpha=0.75)
plt.xlabel('Rate')
plt.ylabel('Count')
plt.title('img_rate')
plt.axis([x_min, x_max, 
        y_min, y_max])
plt.grid(True)
# plt.show()
plt.savefig('hist.png')