Python Data Analysis Cookbook

Analyzing peaks

The analysis of peaks is similar to that of valleys, since both are extreme values. SciPy has the argrelmax() function that finds the relative maxima. When we apply this function to daily temperature values, it not only finds hot days in summer but also hot days in winter unless we make the function consider a larger time frame. Of course, we can also check whether values are above a threshold or only select summer data using prior knowledge.

When we analyze peaks in time series data, we can apply two approaches. The first approach is to consider the highest peaks in a year, a month, or another fixed time interval and build a series with those values. The second approach is to define any value above a threshold as a peak. In this ...