(Fwd) [GRASS-dev] Change the resolution in the output map

Hi coworkers

I have received an answer to my question from Glynn, but I erased it and
I haven't realized. I ask send me the answer again please.

Thanks

Juan

--
********************************
Juan Diego Giraldo Osorio
Tel. 968 327 047
Departamento de Ingeniería Térmica y de Fluidos
Universidad Politécnica de Cartagena
España
********************************

---------- Mensaje reenviado ----------
Para: grass-dev@grass.itc.it
Asunto: [GRASS-dev] Change the resolution in the output map
De: "Juan Diego Giraldo Osorio"<Juan.Giraldo@upct.es>
Fecha: Fri, 30 Nov 2007 17:22:18 +0100 (CET)

Hi coworkers

I'm working with grass62. I'm triying to create a raster map with finer
resolution from another with coarse resolution. The problem is the next:

- My coarse resolution map (input map) have 500 m of resolution, with
1000x1000 rows*cols. This information is the same as the current region.
- I want to create a finer resolution map (output map) with 100 m of
resolution, with 5000x5000 rows*cols.
- I have been trying with the next code:

  /* Adjust the region to new resolution */
  region.rows = nsubpixel*nrows;
  region.cols = nsubpixel*ncols;
  region.format = 0;
  region.compressed = 1;
  G_adjust_Cell_head( &region , 1 , 1 );
  G_set_window(&region);

  nsubpixel is 5 (500/100), and I'm writing a new header file with this
new information (region.rows=5000, region.cols=5000, region.ew_res=100,
region.ns_res=100) but when I read the new map, the next message error
is shows:

  WARNING: error reading null row 115
  ... a lot of times.

Thanks for your help.

Juan Diego Giraldo
--
********************************
Juan Diego Giraldo Osorio
Tel. 968 327 047
Departamento de Ingeniería Térmica y de Fluidos
Universidad Politécnica de Cartagena
España
********************************

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Juan Diego Giraldo Osorio wrote:

I have received an answer to my question from Glynn, but I erased it and
I haven't realized. I ask send me the answer again please.

The list is archived at:

  http://lists.osgeo.org/pipermail/grass-dev/

--
Glynn Clements <glynn@gclements.plus.com>

Juan,

Why don't you just use one of the several resampling methods built into
GRASS instead of writing something in C?

r.resample
r.resample.stats
r.resample.interp
r.resample.rst

Michael

On 12/3/07 3:13 AM, "Juan Diego Giraldo Osorio" <Juan.Giraldo@upct.es>
wrote:

Hi coworkers

I have received an answer to my question from Glynn, but I erased it and
I haven't realized. I ask send me the answer again please.

Thanks

Juan

--
********************************
Juan Diego Giraldo Osorio
Tel. 968 327 047
Departamento de Ingeniería Térmica y de Fluidos
Universidad Politécnica de Cartagena
España
********************************

---------- Mensaje reenviado ----------
Para: grass-dev@grass.itc.it
Asunto: [GRASS-dev] Change the resolution in the output map
De: "Juan Diego Giraldo Osorio"<Juan.Giraldo@upct.es>
Fecha: Fri, 30 Nov 2007 17:22:18 +0100 (CET)

Hi coworkers

I'm working with grass62. I'm triying to create a raster map with finer
resolution from another with coarse resolution. The problem is the next:

- My coarse resolution map (input map) have 500 m of resolution, with
1000x1000 rows*cols. This information is the same as the current region.
- I want to create a finer resolution map (output map) with 100 m of
resolution, with 5000x5000 rows*cols.
- I have been trying with the next code:

/* Adjust the region to new resolution */
region.rows = nsubpixel*nrows;
region.cols = nsubpixel*ncols;
region.format = 0;
region.compressed = 1;
G_adjust_Cell_head( &region , 1 , 1 );
G_set_window(&region);

  nsubpixel is 5 (500/100), and I'm writing a new header file with this
new information (region.rows=5000, region.cols=5000, region.ew_res=100,
region.ns_res=100) but when I read the new map, the next message error
is shows:

  WARNING: error reading null row 115
  ... a lot of times.

Thanks for your help.

Juan Diego Giraldo
--
********************************
Juan Diego Giraldo Osorio
Tel. 968 327 047
Departamento de Ingeniería Térmica y de Fluidos
Universidad Politécnica de Cartagena
España
********************************

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grass-dev@lists.osgeo.org
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Michael Barton, Professor of Anthropology
Director of Graduate Studies
School of Human Evolution & Social Change
Center for Social Dynamics and Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton