Chapter 3: Aggregation Using PROC TIMESERIES
3.1 Aggregation
Observations of continuous series are usually sampled at distinct points in time, leading to discrete equidistant time series. For example, you could record the outdoor temperature at all integer hours. But a series in continuous time could (at least in theory) be observed by some analog recording device, perhaps as a curve drawn on a piece paper. Such a curve could easily be digitalized and converted to a series in discrete time with very short time intervals, such as milliseconds. Modern technical measurement devices produce such curves on the basis of very frequent discrete observations. Such original data sources already have, in reality, the ...
