[STATSGRASS] isolines [solved]
hamish_nospam at yahoo.com
Tue Mar 22 19:02:05 EST 2005
On Tue, 22 Mar 2005 11:45:45 +0100
Tim Michelsen <timmichelsen at gmx-topmail.de> wrote:
> > On Mon, 28 Feb 2005, Tim Michelsen wrote:
> > > > GRASS has limited support for TINs, you would have to extract
> > > > values at the nodes (v.in.ogr? -> vector points), interpolate to
> > > > a raster map using splines (v.surf.rst), then create vector
> > > > isolines with r.contour.
> > >
> > > Do you know any R package that might be able to do the job?
> > No direct route from points to contours without interpolation in R.
> > The nearest I can see would be to use GMT's pscontour, inputting an
> > ASCII xyz file, and dumping the contour line output to file.
> Finally I used contour() in R native to achive it.
> But does anyone know how to plot gradient arrows that demonstrate flow
> E. g. from the higher valued isoline to the lower valued.
Rather crude, but from a raster surface in GRASS you can use
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