[R] Fraction ECDF

[Duncan Murdoch]

On 7/10/2007 10:36 AM, livia wrote:
> Hi all,
> 
> I would like to plot part of the emperical CDF. Suppose the variable is x, I
> just need the part when x>1,therefore, I am using the following codes. 
> 
> tail <- x>1
> plot(ecdf(x[tail]), do.points=FALSE, verticals=TRUE)
> 
> The "x" value starts from 1, but the yaxs still begins from 0, not the
> corresponding value when "x" is 1. How can I make it match?
> 
> Could anyone give me some advice? Many thanks.

Rather than subsetting the x, I'd just use xlim and ylim arguments to 
plot() to change the range.  For example,

plot(ecdf(x), do.points=FALSE, verticals=TRUE, xlim=c(1, max(x)), 
ylim=c(1-sum(x>1)/length(x), 1))

Duncan Murdoch