outer.convhull: Version of outer which operates only in a convex hull

In interp: Interpolation Methods

Version of outer which operates only in a convex hull

Description

This version of outer evaluates FUN only on that part of the grid cx times cy that is enclosed within the convex hull of the points (px,py).

This can be useful for spatial estimation if no extrapolation is wanted.

Usage

outer.convhull(cx,cy,px,py,FUN,duplicate="remove",...)

Arguments

cx	x cordinates of grid
cy	y cordinates of grid
px	vector of x coordinates of points
py	vector of y coordinates of points
FUN	function to be evaluated over the grid
duplicate	indicates what to do with duplicate (px_i,py_i) points, default "remove".
...	additional arguments for FUN

Value

Matrix with values of FUN (NAs if outside the convex hull).

Author(s)

Albrecht Gebhardt <[e-mail]>, Roger Bivand <[e-mail]>

See Also

in.convex.hull

Examples

x<-runif(20)
y<-runif(20)
z<-runif(20)
z.lm<-lm(z~x+y)
f.pred<-function(x,y)
  {predict(z.lm,data.frame(x=as.vector(x),y=as.vector(y)))}
xg<-seq(0,1,0.05)
yg<-seq(0,1,0.05)
image(xg,yg,outer.convhull(xg,yg,x,y,f.pred))
points(x,y)

interp documentation built on May 29, 2024, 8:03 a.m.