I am using R (3.0.1) and ggplot2
(ggplot2_0.9.3.1) with geom_tile
and scale_fill_gradient
. I am using the 'limits
' option in scale_fill_gradient
, as shown below. The problem is that I want to get rid of the grey background that appears outside of the specified limits. I want that background to be white just like the rest of the graph due to theme_bw()
. I have been unable to figure out how to do it. Thanks.
pp <- function (n,r=4) {
x <- seq(-r*pi, r*pi, len=n)
df <- expand.grid(x=x, y=x)
df$r <- sqrt(df$x^2 + df$y^2)
df$z <- cos(df$r^2)*exp(-df$r/6)
df
}
p <- ggplot(pp(20), aes(x=x,y=y))
p + theme_bw() + geom_tile(aes(fill=z)) +
scale_fill_gradient(low="green", high="red", limits = c(-0.1, 0.1))