Self-organizing map (SOM) example in R

SOM example.R

#SOM example using wines data set
library(kohonen)
data(wines)
set.seed(7)

#create SOM grid
sommap <- som(scale(wines), grid = somgrid(2, 2, "hexagonal"))

## use hierarchical clustering to cluster the codebook vectors
groups<-3
som.hc <- cutree(hclust(dist(sommap$codes)), groups)

#plot
plot(sommap, type="codes", bgcol=rainbow(groups)[som.hc])

#cluster boundaries
add.cluster.boundaries(sommap, som.hc)

Getting:

Error in dist(sommap$codes) :
(list) object cannot be coerced to type 'double'

any ideas?

Getting:

Error in dist(sommap$codes) :
(list) object cannot be coerced to type 'double'

any ideas?

Getting

Error in dist(sommap$codes) :
(list) object cannot be coerced to type 'double'

Any one to assist. Am a newbie in R

Getting

Error in dist(sommap$codes) :
(list) object cannot be coerced to type 'double'

Any one to assist. Am a newbie in R

I tried this
som.hc <- cutree(hclust(dist(as.numeric(unlist(sommap$codes)))), groups)
for the error:
Error in dist(sommap$codes) :
(list) object cannot be coerced to type 'double'

and then no more error

but not sure if this is the correct way. I am a newbie too

I tried this
som.hc <- cutree(hclust(dist(as.numeric(unlist(sommap$codes)))), groups)
for the error:
Error in dist(sommap$codes) :
(list) object cannot be coerced to type 'double'

and then no more error

but not sure if this is the correct way. I am a newbie too

following works

som.hc <- cutree(hclust(dist(sommap$codes[[1]])), groups)

following works

som.hc <- cutree(hclust(dist(sommap$codes[[1]])), groups)

i am a little confused about how to do clustering using the result of SOM...

i am a little confused about how to do clustering using the result of SOM...

How can you define the number of groups to be 3?

How can you define the number of groups to be 3?

som.hc <- cutree(hclust(dist(sommap$codes[[1]])), groups)
thanks. this gives no error.

som.hc <- cutree(hclust(dist(sommap$codes[[1]])), groups)
thanks. this gives no error.