[GRASSLIST:8814] Re: r3.in.ascii

[Roger Bivand]

On Sat, 29 Oct 2005 s99171059 at tuks.co.za wrote:

> Dear list,
> 
> I have a raster array which represents cell phone signal strengths, and
> would like to import it into grass 6.  Looks like r3.in.ascii might be
> what I need to import this raster array, as I would like to display the
> signal strengths in different colours.  The help documentation on
> r3.in.ascii seems to be quite concise.  The file nees a header:

Are your data voxels or pixels? r3.* functions are for voxels, and while I 
can think of settings where signal strength at altitude over the surface 
is useful (high-rise buildings?), I'm not sure that you have voxels. If 
you have, then you would have understood that top and bottom are the 
vertical z-range of your pile of voxels, like west-east is the x-range, 
and levels is the number of voxels in the pile. 

> 
> north: floating point
> south: floating point
> east: floating point
> west: floating point
> top: floating point
> bottom: floating point
> rows: integer
> cols: integer
> levels: integer
> 
> I'm not sure what the top, bottom and levels values should be.  Can someone
> pleas elaborate on this?  This is what I found in the help files:
> 
> This header is followed by the cell values in floating point format
> organized in rows with constant col and level coordinate. The rows are
> organized by constant level coordinate. Individual cell values are
> separated by space or CR.
> 
> Regards,
> Kobus
> 

-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no