matplotlib scatter color mapping

import numpy as np
import matplotlib.pyplot as plt

x = np.arange(100)
y = x + np.random.uniform(-5, 5, 100)
t = x
plt.scatter(x, y, c=t, cmap='gist_rainbow')
plt.show()

reference:

https://stackoverflow.com/questions/17682216/scatter-plot-and-color-mapping-in-python

https://www.quantopian.com/lectures/kalman-filters