Plot histograms over factor variables

Question

I'm trying to replicate the graph similar to the following (originally found HERE)

It's conceptually simple, but I'm a bit stumped as to how to do it in R.
To summarize: I want to generate histograms of behavioral frequency over the 24 hours of the day (24-level factor variable) by each day of the week. Then, I want to stack these histograms on top of each other so that the distribution of behavior over the hour of day can easily be compared (again, see example).

For example, my data might look like this:

  weekday hour    count
  Tuesday   15      553
   Monday    1       53
   Monday   10      539
   Monday   15      629
  Tuesday    9      281
 Saturday    4       11
   Monday    3       20
   Sunday    3       10
   Sunday    7        2
   Sunday    2       17

How do I go about implementing the graph in the link above? I'm terrible with ggplot, but have a sense it's the likely solution. Thanks!

Answer 1

Something like this?

set.seed(1234)
df <- data.frame(weekday=rep(sort(unique(weekdays(.leap.seconds))), each=24), 
                       hour=rep(1:24, 7), count=sample(2:600, 24*7, replace=T))

df$weekday <- factor(df$weekday, levels=c("Monday", "Tuesday", "Wednesday", 
                      "Thursday", "Friday", "Saturday", "Sunday"), ordered=T)
df$hour <- factor(df$hour)

require(ggplot2)    
p <- ggplot(data = df, aes(x=hour)) 
p <- p + geom_histogram(aes(weights=count, fill=weekday))
p <- p + scale_fill_brewer(palette="Set3")
p <- p + facet_wrap( ~ weekday, ncol=1)
p