[R] Slope of surface

[Laura Quinn]

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

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