HW2.3-Histogram

import numpy as np
import matplotlib.pyplot as plt
data=np.loadtxt('nonParamTrain.txt')
# calculate bins according to bins size
differ=max(data)-min(data)
bins1=np.math.ceil(differ/0.02)# size 0.02
bins2=np.math.ceil(differ/0.5) # size 0.5
bins3=np.math.ceil(differ/2)   # size 2.0
hist1= np.histogram(data,bins1)
hist2= np.histogram(data,bins2)
hist3= np.histogram(data,bins3)

#plot histogram
figure=plt.figure()
plt.subplot(311);plt.hist(data,bins=bins1,label='bins size=0.02')
plt.legend()
plt.subplot(312);plt.hist(data,bins=bins2,label='bins size=0.5')
plt.legend()
plt.subplot(313);plt.hist(data,bins=bins3,label='bins size=2')
plt.legend()
plt.savefig('histogram')
plt.show()