# Install and load the ggplot package
install.packages("ggplot2")
library(ggplot2)

# Creation of sample data frame
df ＜- data.frame(x = 1:8, 
                 # Each facet on x axis is able
                 # to represent 8 numbers
                   y = 1:8,
                 # Each facet on x axis is able
                 # to represent 8 numbers
                   g1 = rep(LETTERS[1:4], each = 2),
                 # The first four upper case letters
                 # are generated each twice
                   g2 = letters[1:4]
                 # The first four lower case letters
                 # are generated randomly
                )

# Plotting the facet plot using gplot and facet_grid()
plot ＜- ggplot(df, aes(x, y)) + 
  geom_point()+ 
  facet_grid(g1 ~ g2)     
plot

# Removing empty facets from the plot using facet_wrap()
plot <- plot + facet_wrap(g1 ~ g2)
plot