tímaröðinni

Tímaröðin, often translated as the time series, is a sequence of data points or events ordered by time. It is used in statistics, economics, meteorology and other fields to analyze temporal patterns and to describe datasets such as daily stock prices, monthly temperatures, or quarterly GDP.

In statistics, a tímaröð consists of observations collected at regular or irregular time intervals. Key concepts include trend, seasonality, and autocorrelation, while common modeling approaches include ARIMA, exponential smoothing and state-space methods. The goal is often forecasting or understanding the underlying dynamics.

Time series analysis differs from cross-sectional data by preserving temporal ordering and allowing the data to exhibit dependence over time. Analysts address issues such as missing values, non-stationarity, structural breaks, and changing variance, sometimes by transformations or differencing.

The term is also used in historiography and media to refer to a narrative presented in chronological order—a timeline of events. In Icelandic, tímaröðin is the generic term; tímaröðinni is the definite inflected form used with prepositions like í tímaröðinni (in the time series).