How to reshape data for a stacked barchart using R lattice [duplicate]

Answer 1

I hope I'm not missing anything, but it looks to me like you're just looking for table:

table(df[c("date", "classes")])
#         classes
# date     english french spanish
#   9/1/11       1      2       1
#   9/2/11       1      1       0
#   9/3/11       0      0       2
#   9/5/11       2      1       1

The result is a table (which is also a matrix) so you can use your barchart command as you wish.

Here's what I get--looks like you need to work on your legend :-)

The code used was:

language <- table(df[c("date", "classes")])

barchart(prop.table(language), 
         horizontal = FALSE, 
         auto.key = list(space = 'right',
                         cex = .5, border = T, points = F, 
                         lines = F, lwd = 5, 
                         text = c('french','spanish','enligsh'),
                         cex = .6), 
         main = list(label = "Distribution of classes 10", cex = 2.5),
         ylab = list("", cex = 1.7), 
         xlab.top = list("testing", cex = 1.2))