[R-sig-Geo] generate & plot elevation contour lines

[karl.sommer at dpi.vic.gov.au]

Hello list

I am making reference to the graph gallery at
http://r-spatial.sourceforge.net/gallery
I was wondering how one would go about adding elevation contour lines to
the
example fig08?  Presuming that one would have access to a number of
geo-referenced
elevation measurements with a similar density as the sampling locations
indicated with a grey x in fig08. Is there a method to generate contour
lines from such information and overlay it onto the existing interpolated
graph?

Cheers

Karl Sommer
_________________________________
Karl J Sommer,
Department of Primary Industries,
Catchment & Agriculture Services,
PO Box 905
Mildura, VIC, Australia 3502

Tel: +61 (0)3 5051 4390
Fax +61 (0)3 5051 4534

Email:     karl.sommer at dpi.vic.gov.au