from __future__ import print_function, division, absolute_import

import matplotlib
matplotlib.use('TkAgg')
from matplotlib import pyplot as plt

import numpy as np

x = np.linspace(0, 100, num=50)
# Idea: the trending is x, but at each step, it is affected
# by unknown latent factor that create this Gaussian noise
magnitude = 8
noise = np.random.randn(50) * magnitude # standard Gaussian noise, magnifie to see clear effect

y = x[::-1] + noise # we want to so an decreasing trend so reverse x
print(x, y)

plt.plot(x, y)
plt.plot(x, x[::-1], color='r') # the actual trend with the effect of noise
plt.show(block=True)