import numpy as np
import matplotlib.pyplot as plt

# First version using numpy
X = np.genfromtxt('Advertising.csv', skip_header = True, delimiter = ',')

# Explanation of Advertising.csv
# Column 0 - index
idx = X[:,0]
# Column 1 - TV
tv = X[:,1]
# Column 2 - radio
radio = X[:,2]
# Column 3 - newspaper
news = X[:,3]
# Column 4 - sales
sales = X[:,4]


# Exploratory data analysis
# Plot sales against TV, radio and newspaper 
fig1 = plt.figure()

fig1.add_subplot(1,3,1)
plt.plot(tv, sales, 'ro')
plt.xlabel('TV budget')
plt.ylabel('sales')
plt.title('TV ads')

fig1.add_subplot(1,3,2)
plt.plot(radio, sales, 'b+')
plt.xlabel('radio budget')
plt.ylabel('sales')
plt.title('Radio ads')

fig1.add_subplot(1,3,3)
plt.plot(news, sales, 'g.')
plt.xlabel('newspaper budget')
plt.ylabel('sales')
plt.title('Newspaper ads')

plt.show()