www.gusucode.com > stats 源码程序 matlab案例代码 > stats/FindThePruningLevelYieldingTheOptimalInsampleLossExample.m
%% Find the Pruning Level Yielding the Optimal In-sample Loss %% % Load the |carsmall| data set. Consider |Displacement|, % |Horsepower|, and |Weight| as predictors of the response |MPG|. % Copyright 2015 The MathWorks, Inc. load carsmall X = [Displacement Horsepower Weight]; %% % Grow a regression tree using all observations. Mdl = fitrtree(X,MPG); %% % View the regression tree. view(Mdl,'Mode','graph'); %% % Find the best pruning level that yields the optimal in-sample loss. [L,se,NLeaf,bestLevel] = loss(Mdl,X,MPG,'Subtrees','all'); bestLevel %% % The best pruning level is level 1. %% % Prune the tree to level 1. pruneMdl = prune(Mdl,'Level',bestLevel); view(pruneMdl,'Mode','graph');