1.csv

10.r

ggplot(byHour, aes(x=hour, y=as.numeric(countPerHour))) + 
  geom_bar(aes(fill=user), stat="identity") +
  labs(title="Pages visited per hour of day") +
  ylab("Visits Per Hour") + xlab("Hour of the day") +
  theme_bw() + facet_grid(user~.)

11.r

ggplot(byWeekday, aes(x=weekday, y=as.numeric(countPerDay))) + 
  geom_bar(aes(fill=user), position="dodge") +
  labs(title="Dodge per hour per user") +
  ylab("Visits Per Hour") + xlab("Hour of the day") +
  theme_bw() + coord_flip()

12.r

byWeekdayHour <- ddply(data, .(user, hour, weekday), summarise, countPerHour=sum(pages.visited))

byWeekdayHour$weekday <- factor(
    byWeekdayHour$weekday, 
    levels=c('Wednesday', 'Thursday')
)

ggplot(byWeekdayHour, aes(x=hour, y=as.numeric(countPerHour))) + 
    geom_bar(aes(fill=user), stat="identity") +
    labs(title="Pages visited per hour of day") +
    ylab("Visits Per Hour") + xlab("Hour of the day") +
    theme_bw() + facet_grid(user~weekday)

2.r

require(Hmisc)
require(plyr)
require(ggplot2)

data <- csv.get('path/to/csv-file.csv', header=TRUE)

3.r

data$created.at <- as.POSIXct(
    format(data$created.at, tz="America/Los_Angeles" usetz=TRUE)
)

4.r

data$hour <- format(data$created.at, '%H')

5.csv

user          created.at pages.visited hour
1 julie 2011-11-16 03:31:56            3   03
2 julie 2011-11-16 04:22:33            5   04
3 jack 2011-11-16 07:19:13             8   07
4 jack 2011-11-16 12:39:02             9   12
5 julie 2011-11-17 12:39:02            3   12

6.r

byHour <- ddply(data, .(user, hour), summarise, countPerHour=sum(pages.visited))

7.r

data$weekday <- weekdays(data$created.at)
byWeekday <- ddply(data, .(user, weekday), summarise, countPerDay=sum(pages.visited))

8.r

ggplot(byHour, aes(x=hour, y=as.numeric(countPerHour))) + 
    geom_bar(stat="identity") +
    labs(title="Count per hour for all users") +
    ylab("Visits Per Hour") + xlab("Hour of the day") +
    theme_bw()

9.r

ggplot(byHour, aes(x=hour, y=as.numeric(countPerHour))) + 
  geom_bar(aes(fill=user), position="dodge") +
  labs(title="Dodge per hour per user") +
  ylab("Visits Per Hour") + xlab("Hour of the day") +
  theme_bw()