I using oldlogspline (from logspline package) to model data distributions, and
having a problem.
My data are search area sizes. They are based on circular search radii from
random points to the nearest edge of the nearest grass tussock. Search area
sizes are distributed from 0 (the random point intercepts a tussock) and
upwards (as points are further from any tussocks). The density of all my
distributions (using doldlogspline) are highest at size=0, and decline as
search area increases.
I am most interested in the probability of a value in the distribution being
equal to 0 (ie probability of a direct hit on a tussock). I know I can just use
the proportion of actual hits, but am curious to compare this to an estimate
from a density estimation. Unfortunately when using poldlogspline, this
probability is always=0 (simulated data example is below). How can this be,
given that the density is highest at area=0?
> simdat<-c(rep(0,8),rexp(92))
> myspline<-oldlogspline(simdat,lbound=0)
> poldlogspline(fit=myspline, q=0)
[1] 0
Any help to work out the probability of an area value in my distribution = 0
would be appreciated
Terry Beutel
Agri-Science Queensland
[[alternative HTML version deleted]]
______________________________________________
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.
