I'm fitting regression and classification trees. I thought that the algorithm to fit the tree led to the same result each time. However, when I run the line below
tree1 <- rpart(log_bid_price ~ ., minbucket = 5, cp = 0.001, data = HC, method = "anova")
I get differing plots for the cross-validation parameter. I generate the plot using
What changes between the two plots?