[R] Slope of surface

[Uwe Ligges]

Laura Quinn wrote:

> Hi,
> 
> Is there a neat way of working out the slope of a flat surface in R?
> Given (x,y,z) co-ordinates of the four corners of a square, 

three should be sufficient


 > s there a
> function which will allow me to calculate the "mean" slope of the surface
> in a given direction?

Along the axis, one way without any thinking is to apply a regression 
with e=0, the neater way is to calculate the true result simply. Just 
insert one formula into the other ...

Uwe Ligges


> Thanks in advance..
> 
> Laura
> 
> Laura Quinn
> Institute of Atmospheric Science
> School of Earth and Environment
> University of Leeds
> Leeds
> LS2 9JT
> 
> tel: +44 113 343 1596
> fax: +44 113 343 6716
> mail: laura at env.leeds.ac.uk
> 
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