[R] problem with plotting clustered data with convex hull using ggfortify

Karl Schilling
Sun, 24 Oct 2021 20:57:26 -0000

Dear all:

I have some data that I want to cluster and display as groups surrounded
by convex hulls. Here, i use the iris data as an example:

library(ggfortify)
autoplot(fanny(iris[-5], 3), frame = TRUE)

I used this code before, about a year ago, and then it resulted in data
surrounded by convex hulls., just as may be seen in the description of
ggfortify here:


http://rstudio-pubs-static.s3.amazonaws.com/53162_cd16ee63c24747459ccd180f69f07810.html


Presently, no hulls are drawn; instead some line is projected on each
cluster.

I found out that there is an addition to autoplot command, "frame.type =
c("convex", "norm", "t"). Whereas
""norm" and "t"  give confidence
ellipses as expected, "convex" results in a straight line as mentioned
above.

Any help would be appreciated.

Best

--
Karl Schilling