On 28/01/12 11:44, Duke wrote:
Hi folks,
I know that density function will give a estimated density for a give
dataset. Now from that I want to have a percentage estimation for a
certain range. For examle:
> y = density(c(-20,rep(0,98),20))
> plot(y, xlim=c(-4,4))
Now if I want to know the percentage of data lying in (-20,2).
Basically it should be the area of the curve from -20 to 2. Anybody
knows a simple function to do it?
You could try:
foo <- with(y,splinefun(x,y))
integrate(foo,lower=-20,upper=2)
Note that
integrate(foo,lower=min(y$x),upper=max(y$x))
yields "1.000951 with absolute error < 0.00011", rather than giving
exactly 1, so there's a bit of slop in the system.
cheers,
Rolf Turner
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
