# Denis White's maptree package
library(maptree)
data(oregon.env.vars, oregon.grid, oregon.border)
names(oregon.env.vars)
attach(oregon.env.vars)
# regression tree of Oregon environmental variables
model.tree1 <- bird.spp ~ jan.temp+jul.temp+rng.temp
+ann.ppt+min.elev+rng.elev+max.slope
bird.tree1 <- rpart(model.tree1)
plot(bird.tree1)
text(bird.tree1)
# prune the tree
group <- group.tree(clip.rpart(rpart(model.tree1), best=7))
plot(clip.rpart(rpart(model.tree1), best=7))
text(clip.rpart(rpart(model.tree1), best=7))
# plot the regression tree
names(group) <- row.names(oregon.env.vars)
map.groups(oregon.grid, group=group)
map.key (0.05, 0.6, labels=as.character(seq(6)),pch=19, head="node")
lines(oregon.border)
draw.tree (clip.rpart(rpart(model.tree1), best=7), nodeinfo=TRUE,
units="species", cases="cells", cex=.7, pch=16, digits=0)