Ok, so I have a vector file with a bunch of attributes, some of which are
class names. I want to convert this vector coverage to a raster image based
on one of the attributes, where the attribute classes get converted to an
integer (I can manually create an integer field, if this makes it more
complicated). How do I go about this?
A second issue is that this is going to output a rather massive raster
(probably ~ 7gb), forgetting about 64-bit issues for a minute, does anyone
know if the vector-> raster conversion is optimized (e.g. Does it create the
raster row by row or is it going to attempt to load the entire raster into
memory?), or am I going to see this choke?
Thanks!
--j
--
Jonathan A. Greenberg, PhD
NRC Research Associate
NASA Ames Research Center
MS 242-4
Moffett Field, CA 94035-1000
Office: 650-604-5896
Cell: 415-794-5043
AIM: jgrn307
MSN: jgrn307@hotmail.com
Jonathan Greenberg napsal(a):
Ok, so I have a vector file with a bunch of attributes, some of which are
class names. I want to convert this vector coverage to a raster image based
on one of the attributes, where the attribute classes get converted to an
integer (I can manually create an integer field, if this makes it more
complicated).
You need prepare the column manualy
How do I go about this?
*v.to.rast* needs integer or floating point type
A second issue is that this is going to output a rather massive raster
(probably ~ 7gb), forgetting about 64-bit issues for a minute, does anyone
know if the vector-> raster conversion is optimized (e.g. Does it create the
raster row by row or is it going to attempt to load the entire raster into
memory?), or am I going to see this choke?
I heart GRASS process the raster file row by row (r.mapcalc), hope v.to.rast works the same way.
I tried v.to.rast on 90000x55000 raster from 17000 polygon vector, it took 1,5 hour on P4 2 GHz, 512 RAM 
(but only a few minutes on ArcGIS 
).
Záboj Hrázský
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