How to add Voronoi diagramm?

Question

I would like to add a Voronoi plot to my clusters. That is, I would like to have one plot with my clusters, centroids + the Voronoi regions. Is there a simple way to do it?

I tried:

                    x<-c(4,7,9,2,3,3,7,7,8,8,9,9)
                    y<-c(6,3,3,6,5,7,2,9,4,9,2,8)

                    mat<-cbind(x,y)# defining matrix
                    Kmeans<-kmeans(mat,centers=3) # with 3 centroids
                    plot(x,y,col=Kmeans$cluster,pch=19,cex=2)
                    points(Kmeans$centers,col=1:3,pch=3,cex=3,lwd=3)

                    library(tripack)
                    test<-voronoi.mosaic(x,y)
                    plot(x,y,col=Kmeans$cluster,pch=19,cex=2)
                    plot(test)

Here I just dont know how to combine them to produce a reasonable plot.

Perhaps you're looking for a line/border that discriminates between clusters, like that for linear discriminant analysis? — Roman Luštrik, Nov 23 '14 at 14:25

LyzandeR · Accepted Answer · 2014-11-23T17:37:03.397

You mean just plot one on top of the other?

You are using the voronoi.mosaic on x and y and not on the clusters. I don't know how this will help you but to plot one on top of the other you need to do the following:

library(tripack)
x<-c(4,7,9,2,3,3,7,7,8,8,9,9)
y<-c(6,3,3,6,5,7,2,9,4,9,2,8)

mat<-cbind(x,y)# defining matrix
Kmeans<-kmeans(mat,centers=3) # with 3 centroids

test<-voronoi.mosaic(x,y)
plot(x,y,col=Kmeans$cluster,pch=19,cex=2)
points(Kmeans$centers,col=1:3,pch=3,cex=3,lwd=3)
par(new=T)
plot(test)

enter image description here

Initially, I thought you wanted to plot the clusters and the centroids and I did something completely different. You can check that too in the edits.

How to add Voronoi diagramm?

1 Answers1

Linked