The trend is the component of a time series that represents variations of low frequency in a time series, the high and medium frequency fluctuations having been filtered out .
Read moreWhat are the models in time series?
Models for time series data can have many forms and represent different stochastic processes. When modeling variations in the level of a process, three broad classes of practical importance are the autoregressive (AR) models, the integrated (I) models, and the moving average (MA) models .
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