interp: outer.convhull – R documentation

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outer.convhull

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 <albrecht.gebhardt@aau.at>, Roger Bivand <roger.bivand@nhh.no>

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

Interpolation Methods

v1.0-33

GPL (>= 2)

Authors

Albrecht Gebhardt [aut, cre, cph] (...), Roger Bivand [aut], David Sinclair [aut, cph]

Initial release

2020-01-07