# NOT RUN {
# If we would like to see the numbers from plot:
# ?getOption("verbose")
# options(verbose=TRUE)
# options(verbose=FALSE)
# -----
# Draw a depth first search illustration
# -----
dend <- 1:5 %>% dist %>% hclust %>% as.dendrogram
get_nodes_xy(dend)
# polygon(get_nodes_xy(dend), col = 2)
plot(dend,
leaflab = "none",
main = "Depth-first search in a dendrogram")
xy <- get_nodes_xy(dend)
for(i in 1:(nrow(xy)-1)) {
arrows(xy[i,1], xy[i,2], angle = 17,
length = .5,
xy[i+1,1], xy[i+1,2],
lty = 1, col = 3, lwd = 1.5)
}
points(xy, pch = 19, cex = 4)
text(xy, labels = 1:nnodes(dend),cex = 1.2, col = "white", adj = c(0.4,0.4))
# }
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