%% AR Model with No Constant Term
% This example shows how to specify an AR(p) model with constant term equal to zero. Use name-value syntax to specify a model that differs from the default model.
% Specify an AR(2) model with no constant term,
% {y_t} = {\phi _1}{y_{t - 1}} + {\phi _2}{y_{t - 2}} + {\varepsilon _t},
% where the innovation distribution is Gaussian with constant variance.

Mdl = arima('ARLags',1:2,'Constant',0)

% The ARLags name-value argument specifies the lags corresponding to nonzero AR coefficients. The property Constant in the created model object is equal to 0, as specified. The model object has default values for all other properties, including NaN values as placeholders for the unknown parameters: the AR coefficients and scalar variance.
% You can modify the created model object using dot notation, or input it (along with data) to estimate.
% Copyright 2015 The MathWorks, Inc.