Exercises Unit D - Conceptual
Bachelor’s Degree Programme in Philosophy, International and Economic Studies, Ca’ Foscari University of Venice.
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Chapter 8, Exercise 1
Draw an example (of your own invention) of a partition of a two-dimensional feature space that could result from recursive binary splitting. Your example should contain at least six regions.
Then, draw the decision tree corresponding to this partition. Be sure to clearly label all aspects of your figures, including the regions R_1, R_2, \ldots, the cutpoints t_1, t_2, \ldots, and any relevant feature axes.
Hint: Your result should resemble Figures 8.1 and 8.2.
Chapter 8, Exercise 4
This question refers to the plots in Figure 8.14 of An Introduction to Statistical Learning with Applications in R (2nd ed.), p. 362.
(a). Sketch the decision tree corresponding to the partition of the predictor space shown in the left-hand panel of Figure 8.14. The numbers inside the boxes represent the mean of Y within each region.
(b). Create a diagram similar to the left-hand panel of Figure 8.14 using the tree shown in the right-hand panel of the same figure. Divide the predictor space into the appropriate regions and indicate the mean of Y within each region.
Chapter 8, Exercise 6
Provide a detailed explanation of the algorithm that is used to fit a regression tree.