1. Create some artificial dataset

We created some random variable and stack them up together

In [2]:
np.random.seed(34)

x1 = np.random.randn(500)*0.5+3
x2 = np.random.randn(500)*0.5+2

x3 = np.random.randn(500) *0.5 + 4
x4 = np.random.randn(500) *0.5 + 5