library(GGally)
library(ggplot2)
data(diamonds, package="ggplot2")
diamonds.samp <- diamonds[sample(1:dim(diamonds)[1],100),]
gpd <- ggparcoord(data = diamonds.samp,columns = c(1,5:10),groupColumn = 2)
throws the error
> Error: (list) Object can not be converted to 'double'
This is from the examples from GGally. Is this (another) bug?
Run again from a clean session.