Hi Glynn Clements, Thanks for your reply. In fact I need to generate a (uncontroled) distance map from all my values=1. I confess that I don´t understood how r.grow will help me on this task. I need to build a for looping and grow and grow many times the new generated map? Or is there a a way of simple generate a distance map on one command?
Remembering that I am new in GRASS and that I run under windows. Thanks in advance, miltinho astronauta brazil 2008/7/21, Glynn Clements <[EMAIL PROTECTED]>: > > > Milton Cezar Ribeiro wrote: > > > I just started to use GRASS, and I am working with a (almost to me) very > > large dataset into GRASS 6.3.0 NATIVE WINDOWS > > I imported an Erdas image file using Gdal. Apparently I looks fine, > because > > GRASS understood and create a Mapset with all informations contained on > my > > IMG file (like projection, number of cells, bounding box, etc.). > > > > The raster map is 60,000x48,000 pixels. > > > > I tryed display my raster map (it is a binary map with values 0 and 1), > but > > I can see the binary map. > > How can I display my raster map on Map Display 1? I notice that "d.raster > > teste" send the output to .tmp directory (or something like). > > > > But my biggest problem is that I need to generate a Distance Map from > those > > pixels which values is 1. > > > > I tryed "r.buffer input=test output=teste_buffer distances=50,100" (it is > in > > meters) > > but GRASS return a erros message telling that can´t allocate memory > > r.buffer tries to read the entire map into memory, which isn't going > to work with a map that large (it would need 2.8GB; even if you have > that amount of RAM, a 32-bit OS probably isn't going to let you have > that much in a single block). > > r.grow doesn't suffer from the memory issues of r.buffer. It only > keeps in memory as many rows as are necessary given the size of the > buffer (i.e. 2*radius+1 rows). > > It doesn't support multiple distance zones, so you would need to use > multiple passes and patch the results together with r.patch. > > -- > Glynn Clements <[EMAIL PROTECTED]> >
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