surf.ls: Fits a Trend Surface by Least-squares

Description Usage Arguments Value References See Also Examples

View source: R/kr.R

Description

Fits a trend surface by least-squares.

Usage

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surf.ls(np, x, y, z)

Arguments

np

degree of polynomial surface

x

x coordinates or a data frame with columns x, y, z

y

y coordinates

z

z coordinates. Will supersede x$z

Value

list with components

beta

the coefficients

x
y
z

and others for internal use only.

References

Ripley, B. D. (1981) Spatial Statistics. Wiley.

Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer.

See Also

trmat, surf.gls

Examples

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library(MASS)  # for eqscplot
data(topo, package="MASS")
topo.kr <- surf.ls(2, topo)
trsurf <- trmat(topo.kr, 0, 6.5, 0, 6.5, 50)
eqscplot(trsurf, type = "n")
contour(trsurf, add = TRUE)
points(topo)

eqscplot(trsurf, type = "n")
contour(trsurf, add = TRUE)
plot(topo.kr, add = TRUE)
title(xlab= "Circle radius proportional to Cook's influence statistic")

Example output



spatial documentation built on May 29, 2017, 8 p.m.