%% estimateProcedure
%
% (string)  Precedure that is used for estimation (default: 'LS').
%
% This property indicates which procedure should be used to estimate the
% coefficients of the polynomial. 
% 
% "LS" uses the complete given xRegressor for the approximation by solving
% the least-sqares-problem.
%
% "STEPWISE_LS" uses "stepwisefit" to search for a specific number of the
% given xRegressors depending on their importance. Afterwards their
% coefficients are estimate by least-squares. 
%
% "RIDGE" uses ridge regression to calculat the model parameters