Python Feature Engineering Cookbook

Getting ready

Local maxima or local minima, also known as extrema, are the largest or smallest values of a function either within a certain range or in the entire domain of the function. They signal a change in the trend of the function. Here, local maxima come after an increase and prior to a decrease in the values of the function, whereas local minima come after a decrease and prior to an increase in the values of the function.

To find local extrema, we will use the find_peaks function from the signal module from SciPy, which finds all the local maxima by performing a simple comparison of neighboring values.