A “time series” is a set of measured values separated by regular, or irregular, intervals in time. An example might be the temperature recorded from a thermistor every minute. The resulting time series, when plotted, will show how the temperature varied over time. The statistics of these variations are often of great interest. If it is a long record (i.e. decades), it might reveal climate variations. Short records might show daily heating and cooling, or the influence of mixing. Intermediate length records might show seasonal variations. Simple statistics might include the mean (average), or trend (slope) of the time series. The mean and trend are the first and second modes of a time series. More advanced analysis, i.e. auto-correlations and ...