### *** Motorcycle Data *** ### library(tree) library(randomForest) library(MASS) # data data(mcycle) par(mfrow=c(1,2)) mct <- tree(accel ~ times, data=mcycle) plot(mct, col=8) text(mct, cex=.75, font=2) ## create a grid of times to predict over timegrid <- data.frame(times=seq(1,60,length=1000)) ## plot my fitted tree surface plot(mcycle, pch=21, bg=8) lines(timegrid$times, predict(mct, newdata=timegrid), col=2, lwd=3) ## now do it with random forests rfmc <- randomForest(accel ~ times, data=mcycle, ## works fine without below, but in this example this ## gives a better looking tree. nodesize is min leaf size nodesize=10) pred.rfmc <- predict(rfmc, timegrid) plot(mcycle, pch=21, bg=8) lines(timegrid$times, pred.rfmc, col=2, lwd=2) ## plot doesn't produce a nice dendrogram... why? plot(rfmc) # this is just the MSE as you increase your sample of trees