Time Series Visualization and Analysis
Jerry D. Davis · 2023
This chapter looks at a variety of methods for working with data over time. A time series is comprised of a series of samples of a phenomenon at a specific time interval, such as 10 seconds, 4 hours, 1 day, or 20 years, where that interval might be the time spacing of observations such as temperature, precipitation, solar radiation, or water quality, to name a few of the many environmental parameters commonly monitored by government agencies. Sunspot activity is known to fluctuate over about a 11-year cycle, and other than the well-known effects on radio transmission is also part of short-term climate fluctuations. The sunspot cycle varies significantly; and since we can see that the random variation is much greater than the seasonal, this suggests that we might not be able to use this periodicity reliably.