find peak and bottom values from a series

Find every local peaks and bottom values

import numpy as np

from scipy import signal

import matplotlib.pyplot as plt

data = np.array([ 0.1, 1, 3, 1, 0.2, 1, 3.1, 3.2, 3, 1, 0 , -0.1, -0.2, -0.1, -0.2])

peak_index = signal.argrelextrema(data, np.greater_equal, order=1)

bottom_index = signal.argrelextrema(data, np.less_equal, order=1)

print('peak values are {}'.format(data[peak_index]))

print('bottom values are {}'.format(data[bottom_index]))

fig = plt.figure()

plt.plot(range(len(data)), data)

plt.scatter(peak_index, data[peak_index], color = 'red')

plt.scatter(bottom_index, data[bottom_index], color = 'blue')

plt.show()