Fig. 2
From: Evaluation of tree-based statistical learning methods for constructing genetic risk scores
Exemplary tree models for three binary input variables \(X_1\), \(X_2\) and \(X_3\) predicting two different classes \(c_0\) and \(c_1\). In a, a classification tree is shown. b depicts a logic tree describing the Boolean expression \((X_1^c \wedge X_2) \vee (X_1 \wedge X_3^c)\). Here, a true Boolean expression is identified as class \(c_1\) and \(c_0\) otherwise. Negated input variables/leaves are marked by white letters on a black background. Both trees are equivalent, i.e., they perform the same predictions for each predictor setting