Filling under the a curve with ggplot graphs

Question

I would like to create a graph with the normal function from x=-2 to x=2 filled under the curve from -2 to 0. I've tried with ggplot2

qplot(c(-2, 2), stat="function", fun=dnorm, geom="line") +
+ geom_area(aes(xlim=c(-2,0)),stat="function", fun=dnorm)

But I get this graph completely filled instead (the black colour)

How can I get a plot filled only from -2 to 0?

Other options or packages are welcome.

I've also tried with only one command with ggplot and filled option but I can't get it either.
I know some people does it using polygons but the result is not so soft and nice.

PD: I repeat, the solution I'm looking for involves not generating x,y coordinates beforehand but using directly the function with stat="function", fun=dnorm or similar. Thus, my question is not a duplicate.

I've also tried

ggplot(NULL,aes(x=c(-2,2))) +  geom_area(aes(x=c(-2,0)),stat="function", fun=dnorm, fill="red") +
geom_area(aes(x=c(0,2)),stat="function", fun=dnorm, fill="blue")  

But again it fills all the curve with a single color, blue. The red half seems to be overwritten. The same with geom_ribbon and other options.

Answer 1

Try this:

ggplot(data.frame(x = c(-2, 2)), aes(x)) +
  stat_function(fun = dnorm) + 
  stat_function(fun = dnorm, 
                xlim = c(-2,0),
                geom = "area") 

Answer 2

Can't you generate your distribution data with dnorm instead?

library(ggplot2)
x<-seq(-2,2, 0.01)
y<-dnorm(x,0,1)
xddf <- data.frame(x=x,y=y)
qplot(x,y,data=xddf,geom="line")+
  geom_ribbon(data=subset(xddf ,x>-2 & x<0),aes(ymax=y),ymin=0,
              fill="red",colour=NA,alpha=0.5)+
  scale_y_continuous(limits=c(0, .4))