jones christian
2006-Apr-29 17:33 UTC
[R] How to get predicted probabilities out of a class.tree
Hello! I would like to use a classification tree as a species modelling method. The dependent variable is binary (0,1),the independent variables are numeric. So I have to surround the dependent variable with factor(). That tells tree() that I want a logistic, or classification, tree rather than a regression tree. Here the code (tree(formula = factor(y) ~ x1 + x2 + x3) For interpretation reasons I prefer to have the predicted probabilities between 0 and 1 at every leaf point but as a result I only get a discret value of 0 or 1. Leaving out "factor" plots the desired predicted probabilities but then the selected variables differ (decision rules of classification vs regression tree)and above all I guess this would violate the convention?! So does anyone know how to go about this? many thanks in advance Christian -- _______________________________________________ Search for businesses by name, location, or phone number. -Lycos Yellow Pages http://r.lycos.com/r/yp_emailfooter/http://yellowpages.lycos.com/default.asp?SRC=lycos10