[GRASSLIST:2046] mapcalc for sites?

Is there a way within GRASS to do calculations on sites? I have some depth soundings that imports into float attributes to my sites and need to convert them to elevations (and to meters) before I run one of the surf commands. I would rather not go outside of GRASS to do it (too much import/export hassle), but I have the tools if necessary.

-----
William Kyngesburye <kyngchaos@charter.net>
http://webpages.charter.net/kyngchaos/

"Those people who most want to rule people are, ipso-facto, those least suited to do it."

- A rule of the universe, from the HitchHiker's Guide to the Galaxy

Is there a way within GRASS to do calculations on sites? I have some
depth soundings that imports into float attributes to my sites and
need to convert them to elevations (and to meters) before I run one of
the surf commands. I would rather not go outside of GRASS to do it
(too much import/export hassle), but I have the tools if necessary.

Probably best to do it externally.

s.out.ascii sites_file -ad fs=, > site_data.dat

Then

if the number of soundings is small:
load into a spreadsheet and make the changes you need.

if the number of soundings is large:
load into something like Octave or Matlab & do your thing.

Save in a similar CSV format & re-import with s.in.ascii. Mind the
spreadsheet hasn't rounded your data on a whim as some of them are want
to do.

Within GRASS, you can only do stats on the site data, not actually
change them, AFAIK.

good luck,
Hamish

On Tue, 16 Dec 2003, Hamish wrote:

> Is there a way within GRASS to do calculations on sites? I have some
> depth soundings that imports into float attributes to my sites and
> need to convert them to elevations (and to meters) before I run one of
> the surf commands. I would rather not go outside of GRASS to do it
> (too much import/export hassle), but I have the tools if necessary.

Probably best to do it externally.

s.out.ascii sites_file -ad fs=, > site_data.dat

Then

if the number of soundings is small:
load into a spreadsheet and make the changes you need.

if the number of soundings is large:
load into something like Octave or Matlab & do your thing.

Save in a similar CSV format & re-import with s.in.ascii. Mind the
spreadsheet hasn't rounded your data on a whim as some of them are want
to do.

Within GRASS, you can only do stats on the site data, not actually
change them, AFAIK.

An alternative if you use R and the R/GRASS interface is sites.get() to R,
do the computations, then sites.put2() back again. But for smaller
operations, use the other suggestions to save installing extra software.

Roger

good luck,
Hamish

--
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Breiviksveien 40, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 93 93
e-mail: Roger.Bivand@nhh.no

the surf commands. I would rather not go outside of GRASS to do it
(too much import/export hassle), but I have the tools if necessary.

Probably best to do it externally.

s.out.ascii sites_file -ad fs=, > site_data.dat
.

Oh, well. I went thru FileMaker.

Now to play with the r.surf.rst options...

-----
William Kyngesburye <kyngchaos@charter.net>
http://webpages.charter.net/kyngchaos/

"History is an illusion caused by the passage of time, and time is an illusion caused by the passage of history."

- Hitchhiker's Guide to the Galaxy