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Autoregressive model. In statistics, econometrics, and signal processing, an autoregressive (AR) model is a representation of a type of random process; as such, it can be used to describe certain time-varying processes in nature, economics, behavior, etc. The autoregressive model specifies that the output variable depends linearly on its own ...
Vector autoregression (VAR) is a statistical model used to capture the relationship between multiple quantities as they change over time. VAR is a type of stochastic process model. VAR models generalize the single-variable (univariate) autoregressive model by allowing for multivariate time series.
In statistics and econometrics, and in particular in time series analysis, an autoregressive integrated moving average (ARIMA) model is a generalization of an autoregressive moving average (ARMA) model. To better comprehend the data or to forecast upcoming series points, both of these models are fitted to time series data.
The notation ARMA(p, q) refers to the model with p autoregressive terms and q moving-average terms.This model contains the AR(p) and MA(q) models, [5]= + = + =. The general ARMA model was described in the 1951 thesis of Peter Whittle, who used mathematical analysis (Laurent series and Fourier analysis) and statistical inference.
Box–Jenkins method. In time series analysis, the Box–Jenkins method, [1] named after the statisticians George Box and Gwilym Jenkins, applies autoregressive moving average (ARMA) or autoregressive integrated moving average (ARIMA) models to find the best fit of a time-series model to past values of a time series.
"Autoregressive Conditional Heteroscedasticity with Estimates of Variance of United Kingdom Inflation". Econometrica. 50 (4): 987–1008. doi:10.2307/1912773. JSTOR 1912773. S2CID 18673159. (the paper which sparked the general interest in ARCH models) Engle, Robert F. (1995). ARCH: selected readings. Oxford University Press. ISBN 978-0-19-877432-7.
In statistics, autoregressive fractionally integrated moving average models are time series models that generalize ARIMA (autoregressive integrated moving average) models by allowing non-integer values of the differencing parameter. These models are useful in modeling time series with long memory —that is, in which deviations from the long ...
As another example, consider a first-order autoregressive model, defined by x i = c + φx i−1 + ε i, with the ε i being i.i.d. Gaussian (with zero mean). For this model, there are three parameters: c, φ, and the variance of the ε i. More generally, a pth-order autoregressive model has p + 2 parameters.