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Fits a Trend Surface by Least-squares
Usage
surf.ls(np, x, y, z)
Arguments
np
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degree of polynomial surface
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x
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x coordinates or a data frame with columns x , y , z
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y
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y coordinates
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z
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z coordinates. Will supersede x$z
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Description
Fits a trend surface by least-squares.
Value
list with components
beta
|
the coefficients
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x
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y
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z
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and others for internal use only.
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See Also
trmat
Examples
data(topo)
topo.kr <- surf.ls(2, topo)
trsurf <- trmat(topo.kr, 0, 6.5, 0, 6.5, 50)
contour(trsurf$x,trsurf$y,trsurf$z)
points(topo)