How to produce stacked bars within grouped barchart in R [duplicate]

Here is what I came up with, similar to a solution proposed here: stacked bars within grouped bar chart

1. Melt data.frame and add a new column cat

   library(reshape2) # for melt
   
   melted <- melt(test, "person")
   
   melted$cat <- ''
   melted[melted$variable == 'value1',]$cat <- "first"
   melted[melted$variable != 'value1',]$cat <- "second"
   

2. Plot a stacked chart cat vs value, faceting by person. You may need to adjust the labels to get what you want:

   ggplot(melted, aes(x = cat, y = value, fill = variable)) + 
     geom_bar(stat = 'identity', position = 'stack') + facet_grid(~ person)