Means to create a coloured hexagonal "heat map" plot of SOM map from kohonen package.

kohonen-hexagonal-SOM-plot.R

# I cannot remember the source for this code. It isn't mine. Probably somewhere on stackoverflow.




require ("kohonen")
require ("latticeExtra")
require ("deldir")
data(wines)
som.wines <- som (scale (wines), grid = somgrid(5, 5, "hexagonal"))

df <- as.data.frame (cbind (som.wines$grid$pts, som.wines$codes))
levelplot (alcohol ~ x * y, data = df, panel = panel.voronoi, aspect = "iso")

http://stackoverflow.com/questions/19858729/r-package-kohonen-how-to-plot-hexagons-instead-of-circles-as-in-matlab-som-too