pastebin - collaborative debugging

baby <- read.table("data.txt", sep = "\t", header = T)
baby$action_time <- as.POSIXct(strptime(baby$action_time,
  "%Y-%m-%d %H:%M:%s"))
sleep <- subset(baby, action_name %in% c("gnight", "gmorning"))

# Trick to label each sleep period
sleep$period <- cumsum(sleep$action_name == "gnight")

# Now can easily use plyr
library(plyr)

# Remove cases that don't have exactly two observations
sleep <- ddply(sleep, "period", function(df) {
  if (nrow(df) == 2) {
    df
  }
})

# This is the data format that's most useful for plotting.  However, rather
# than going through the gymnastics to get it into this format, I'd suggest
# having a separate data frame for interval events where you record the
# start and end of each event - i.e. just like this format
asleep <- ddply(sleep, "period", summarise,
  start = action_time[action_name == "gnight"],
  end =   action_time[action_name == "gmorning"]
)
asleep$length <- with(asleep, as.numeric(difftime(start, end,
  units = "mins")))

library(ggplot2)

print(qplot(start, length, data = asleep, geom = "line"))
print(qplot(start, length / 60, data = asleep, ylab = "hours"))

asleep$hour <- as.POSIXlt(asleep$start)$hour + 1
qplot(hour, length / 60, data = asleep, geom = "boxplot", group = hour)
ggsave(file = "ggplot2test.png")

qplot(hour, length/60, data=asleep, alpha=I(1/10))