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

karl.sommer at dpi.vic.gov.au karl.sommer at dpi.vic.gov.au
Tue Jun 27 09:29:39 CEST 2006

my understanding is that adding the "contour = TRUE" will add the contour
lines for kriged zinc concentration in the present example.

However, what I am after is to superimpose contour lines of elevation in
meters above sea level on top of an interpolated variable that is not
elevation, eg zinc concentration or some other variable.

I have an interpolated maps of an electromagnetic survey  (EM38) of a field
and I would like to overlay a plot of contour lines to visualize surface
drainage patterns.



|         |           e.pebesma at geo.uu.|
|         |           nl               |
|         |                            |
|         |           27/06/2006 16:55 |
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  |                                                                                                                              |
  |       To:       karl.sommer at dpi.vic.gov.au                                                                                   |
  |       cc:       r-sig-geo at stat.math.ethz.ch                                                                                  |
  |       Subject:  Re: [R-sig-Geo]  generate & plot elevation contour lines                                                     |

karl.sommer at dpi.vic.gov.au wrote:
> 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
> ________________________________
Simpler than I thought it would be: add contour = TRUE to the argument list
of spplot.

If you want the actual contours, there is a contourLines function that
returns them; sp has a function to convert these to
SpatialLinesDataFrame objects: contourLines2SLDF().

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