Hello all,
I did a raster file based on a sites files after an IDW interpolation.
I would like to extract from the raster file the area where there are points,
i.e. I would like to erase part of the raster where IDW did not have points
to compute "true" values.
How can I do that with Grass
--
Cordialy
----------------------------------------
Emmanuel POIZOT
Cnam/Intechmer
Digue de Collignon
50110 Tourlaville
Tél : (33)(0)2 33 88 73 42
Fax : (33)(0)2 33 88 73 39
-----------------------------------------
Poizot Emmanuel said:
Hello all,
I did a raster file based on a sites files after an IDW interpolation.
I would like to extract from the raster file the area where there are
points,
i.e. I would like to erase part of the raster where IDW did not have
points
to compute "true" values.
How can I do that with Grass
Just guessing here, but how about using s.to.rast to transform the sites
file into a raster file (without interpolation) and then use this raster
file as a MASK ?
Moritz
You could experiment with s.to.rast. In the raster output from it, only
the cells that contained points will have data; the others will be null.
This might be what you want or else you could use this as a MASK to
extract the data from your IDW-interpolated raster. Something like
s.to.rast input=sitesfile output=sitesmask
g.copy rast=sitesmask,MASK
r.resample input=idwoutput output=maskedidw
g.remove rast=MASK
On Fri, 4 Jul 2003, Poizot Emmanuel wrote:
Hello all,
I did a raster file based on a sites files after an IDW interpolation.
I would like to extract from the raster file the area where there are points,
i.e. I would like to erase part of the raster where IDW did not have points
to compute "true" values.
How can I do that with Grass
--
Cordialy
----------------------------------------
Emmanuel POIZOT
Cnam/Intechmer
Digue de Collignon
50110 Tourlaville
Tél : (33)(0)2 33 88 73 42
Fax : (33)(0)2 33 88 73 39
-----------------------------------------