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bivariate kernel density estimates at point locations (rather than at grid locations)

2 messages · Strickland, Matthew, Adelchi Azzalini

Strickland, Matthew
# 
Hi,

My data consists of a set of point locations (x,y). 

I would like to know if there is a procedure for bivariate kernel
density estimation in R that returns the density estimates at the
observed point locations rather than at grid locations. I have looked at
a number of different routines and they all seem to return estimates at
grid locations.  

Any type of kernel is fine (i.e., Gaussian, Quartic, etc).  

Thank you for your help!

Matt Strickland
U.S. Centers for Disease Control and Prevention
Adelchi Azzalini
#
On Thu, 15 Dec 2005 14:21:17 -0500, Strickland, Matthew wrote:
SM> Hi,
SM> 
SM> My data consists of a set of point locations (x,y). 
SM> 
SM> I would like to know if there is a procedure for bivariate kernel
SM> density estimation in R that returns the density estimates at the
SM> observed point locations rather than at grid locations. I have
SM> looked at a number of different routines and they all seem to
SM> return estimates at grid locations.  
SM> 

One option is to use (from package sm), 
  sm.density(xy, eval.points=xy, eval.grid=FALSE)
where xy in a (n\times 2) matrix.

Best wishes,
Adelchi Azzalini