[GRASS-user] r3.in.ascii - Difficulties understanfing format

[Nikos Alexandris]

On Tue, 2009-01-13 at 04:55 -0800, Tom van der Putte wrote:
> I'm relatively new to Grass, but I need to import 3D ascii files. For testing
> purposes, I altered precip3D_500z50 (from Slovakia Precipitation, GRASS data
> downloads) into the following:
> 
> north: 5530000.000000
> south: 5275000.000000
> east: 4631000.000000
> west: 4186000.000000
> top: 3000.000000
> bottom: 0.000000
> rows: 3
> cols: 3
> levels: 3
> 1.00000 1.00000 2.00000
> 1.00000 1.00000 1.00000
> 1.00000 1.00000 1.00000
> 1.00000 2.00000 2.00000
> 1.00000 1.00000 2.00000
> 3.00000 1.00000 1.00000
> 2.00000 2.00000 2.00000
> 3.00000 2.00000 2.00000
> 3.00000 3.00000 2.00000
> 
> I kept everything from North - Bottom the same, just altered the rows, cols,
> levels and cells. When I visualise this in NVIZ, all is well. But when I
> alter the North-Bottom parameters as such:
> 
> north: 3.000000
> south: 0.000000
> east: 3.000000
> west: 0.000000
> top: 3.000000
> bottom: 0.000000
> 
> I do not get an error, but I cannot visualise anything. What I'm trying to
> do is to understand al these parameters, so I can automate output from other
> data sources. Can anybody help me with this problem? Thanks!
> 
> Tom van der Putte 

Tom, if your data are defined on a metric projection system, as the
initial region settings suggest, then you only mess-up the region by
setting, e.g., the north boundary from "north: 5530000.000000" to
"north: 3.000000".

In simple words, the area that will show up with your region-definitions
does not coincide with your data (which are "locked"=georeferenced to a
specific geographic location on the earth's surface).

Hopefully I helped somehow.

Kind regards, Nikos