Fits a Trend Surface by Least-squares
DESCRIPTION:
Fits a trend surface by least-squares.
USAGE:
surf.ls(np, x, y, z)
residuals.trls(object, ...)
fitted.trls(object, ...)
deviance.trls(object, ...)
df.residual.trls(object, ...)
extractAIC.trls(fit, scale, k = 2, ...)
REQUIRED 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
- object, fit
-
a fit inheriting from class
"trls"
OPTIONAL ARGUMENTS:
- scale
-
unused for this method
- k
-
the multiple of the number of degrees of freedom to be used.
- ...
-
arguments passed to or from other methods.
VALUE:
list with components
- beta
-
the coefficients
- x
-
- y
-
- z
-
and others for internal use only.
SEE ALSO:
,
EXAMPLES:
library(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 = T)
points(topo)
eqscplot(trsurf, type = "n")
contour(trsurf, add = T)
plot(topo.kr, add = T)
title(xlab = "Circle radius proportional to Cook's influence statistic")