ggplot2 legend to bottom and horizontal

Question

How can I move a ggplot2 legend to the bottom of the plot and turn it horizontally?

Sample code:

library(reshape2) # for melt
df <- m         


        

Answer 1

If you want to move the position of the legend please use the following code:

library(reshape2) # for melt
df <- melt(outer(1:4, 1:4), varnames = c("X1", "X2"))
p1 <- ggplot(df, aes(X1, X2)) + geom_tile(aes(fill = value))
p1 + scale_fill_continuous(guide = guide_legend()) +
    theme(legend.position="bottom")

This should give you the desired result.