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In statistics, an additive model (AM) is a nonparametric regression method. It was suggested by Jerome H. Friedman and Werner Stuetzle (1981) [ 1 ] and is an essential part of the ACE algorithm. The AM uses a one-dimensional smoother to build a restricted class of nonparametric regression models.
An additive model would be used when the variations around the trend do not vary with the level of the time series whereas a multiplicative model would be appropriate if the trend is proportional to the level of the time series. [3] Sometimes the trend and cyclical components are grouped into one, called the trend-cycle component.
The model relates a univariate response variable, Y, to some predictor variables, x i. An exponential family distribution is specified for Y (for example normal, binomial or Poisson distributions) along with a link function g (for example the identity or log functions) relating the expected value of Y to the predictor variables via a structure ...
The generalized additive model for location, scale and shape (GAMLSS) is a semiparametric regression model in which a parametric statistical distribution is assumed for the response (target) variable but the parameters of this distribution can vary according to explanatory variables.
Time series analysis comprises methods for analyzing time series data in order to extract meaningful statistics and other characteristics of the data. Time series forecasting is the use of a model to predict future values based on previously observed values.
Also, the final model depends on the order in which the predictor variables are fit. As well, the solution found by the backfitting procedure is non-unique. If b {\displaystyle b} is a vector such that S ^ b = 0 {\displaystyle {\hat {S}}b=0} from above, then if f ^ {\displaystyle {\hat {f}}} is a solution then so is f ^ + α b {\displaystyle ...
The original model uses an iterative three-stage modeling approach: Model identification and model selection: making sure that the variables are stationary, identifying seasonality in the dependent series (seasonally differencing it if necessary), and using plots of the autocorrelation (ACF) and partial autocorrelation (PACF) functions of the dependent time series to decide which (if any ...
The functional predictors are assumed to be smooth across the time domain since the times contained in an interval domain are an uncountable set, an unrestricted time-additive model is not feasible. This motivates to approximate sums of additive functions by integrals so that the traditional vector additive model be replaced by a smooth ...