%% Modify the Innovation Distribution
% After a model exists in the Workspace, you can modify its Distribution property using dot notation. You cannot modify the fields of the Distribution data structure directly. For example, Mdl.Distribution.DoF = 8 is not a valid assignment. However, you can get the individual fields.
% Start with an MA(2) model:

Mdl = arima(0,0,2);

%
% To change the distribution of the innovation process in an existing model to a Student's t distribution with unknown degrees of freedom, type:

Mdl.Distribution = 't'

%
% To change the distribution to a t distribution with known degrees of freedom, use a data structure:

Mdl.Distribution = struct('Name','t','DoF',8)

%
% You can get the individual Distribution fields:

DistributionDoF = Mdl.Distribution.DoF

%
% To change the innovation distribution from a Student's t back to a Gaussian distribution, type:

Mdl.Distribution = 'Gaussian'

% The Name field is updated to 'Gaussian', and there is no longer a DoF field.
% Copyright 2015 The MathWorks, Inc.