[GRASSLIST:1028] Re: srtm

[Matt Doggett]

What I usually do is convert a states/countries/landmass shapefile (or
vector) into a grid with ones (1) and zeros (or nulls). I use this grid
as a mask for r.mapcalc calculations.

Matt

Matt Doggett
Spatial Climate Analysis Service
Oregon State University
316 Strand Ag Hall
Corvallis, OR 97331
(541)737-9153
mdoggett at coas.oregonstate.edu


-----Original Message-----
From: owner-GRASSLIST at baylor.edu [mailto:owner-GRASSLIST at baylor.edu] On
Behalf Of Ian Macmillan
Sent: Tuesday, August 26, 2003 11:22 AM
To: Kevin Slover
Cc: grasslist at baylor.edu
Subject: [GRASSLIST:1027] Re: srtm

thanks for the suggestions, I thought of that too, but I don't think
that would
work for srtm data.  The data in the oceans is not necessarily negative,
the
values sometimes even get up into the hundreds of meters.  It is
actually
pretty difficult to pick out the coastline with that data set.  I was
thinking
I might be able to somehow turn to null everything outside of a vector
(or
raster) coastline file.

-Ian