Contents
Description of demo_regression_tree.m
Demonstrates stump and tree regression with either constant (mean) or linear (minimizing sum of squares) prediction for each subset of the training data space
clear all close all generateData_consGroups
usage of constant regression stump (consGroups data)
options_st1 = []; options_st1.modelType = 'cns'; model_st1 = ml_regression_stump(Xtrain, ytrain, options_st1); yhat_st1 = model_st1.predict(model_st1, Xtest); testError_st1 = mean(abs(yhat_st1 - ytest)); fprintf('Averaged absolute test error with %s is: %.3f\n', model_st1.name, testError_st1);
Averaged absolute test error with Stump Regression is: 0.254
usage of constant regression tree (consGroups data)
options_tr1 = []; options_tr1.modelType = 'cns'; options_tr1.splitSample = 'bf'; model_tr1 = ml_regression_tree(Xtrain, ytrain, options_tr1); yhat_tr1 = model_tr1.predict(model_tr1, Xtest); testError_tr1 = mean(abs(yhat_tr1 - ytest)); fprintf('Averaged absolute test error with %s is: %.3f\n', model_tr1.name, testError_tr1);
Averaged absolute test error with Regression Tree is: 0.273
plotRegression1D(Xtrain, ytrain, model_st1, model_tr1);
title('Constant');
generateData_linGroups
usage of linear regression stump (linGroups data)
options_st2 = []; options_st2.modelType = 'lin'; model_st2 = ml_regression_stump(Xtrain, ytrain, options_st2); yhat_st2 = model_st2.predict(model_st2, Xtest); testError_st2 = mean(abs(yhat_st2 - ytest)); fprintf('Averaged absolute test error with %s is: %.3f\n', model_st2.name, testError_st2);
Averaged absolute test error with Stump Regression is: 0.507
usage of linear regression tree (linGroups data)
options_tr2 = []; options_tr2.modelType = 'lin'; options_tr2.splitSample = 'bf'; model_tr2 = ml_regression_tree(Xtrain, ytrain, options_tr2); yhat_tr2 = model_tr2.predict(model_tr2, Xtest); testError_tr2 = mean(abs(yhat_tr2 - ytest)); fprintf('Averaged absolute test error with %s is: %.3f\n', model_tr2.name, testError_tr2);
Averaged absolute test error with Regression Tree is: 0.527
plotRegression1D(Xtrain, ytrain, model_st2, model_tr2);
title('Linear');
