# Generate a random data set to play with
n_obs <- 100
data_set <- data.frame(observation=c(rnorm(n_obs,mean=80,sd=5),rnorm(n_obs,mean=60,sd=5)),population=rep(c("A","B"),each=n_obs))


#
# Using the lattice library
# Included with R
#

library(lattice)

# Box and whisker plot
box_plot <- bwplot(observation ~ population,data=data_set)
box_plot$xlab <- "Observation"


# Violin plot
violin_plot <- bwplot(observation ~ population,data=data_set,panel=panel.violin)
violin_plot$xlab <- "Observation"


# Denstiy plot
density_plot <- densityplot(~ observation,groups=population,data=data_set,auto.key=TRUE)
density_plot$xlab <- "Observation"


#
# Using the ggplot2 library
# IMPORTANT : requires installation, is not included with R
# Also requires the installation of dependency packages
#

library(ggplot2)

# Box whisker again
box_plot_2 <- ggplot(data_set,aes(y=observation,x=population)) + geom_boxplot() + scale_y_continuous("Observation") + scale_x_discrete("Population")



# With points
box_plot_with_points <- box_plot_2 + geom_jitter()


# Density again
density_plot_2 <- ggplot(data_set,aes(x=observation,fill=factor(population))) + geom_density(alpha=0.2) + scale_x_continuous("Observation")


# Histogram
histo_plot <- ggplot(data_set,aes(x=observation,fill=population)) + geom_bar(position="dodge") + scale_x_continuous("Observation")