Margin adjustments when using ggplot's geom_tile()

Question

From the documentation for ggplot2\'s geom_tile() function, we have the following simple plot:

# Generate data 
pp <- function (n,r=4) { 
    x <- seq         


        

Answer 1

Try this:

p + geom_tile() + 
    scale_x_continuous(expand=c(0,0)) + 
    scale_y_continuous(expand=c(0,0))