[GRASSLIST:7714] Re: Raster Resolution (help requested)

[Glynn Clements]

Dave Sampson wrote:

> In the past I have worked mainly with RASTER layers in GRASS and they 
> just worked (some how). Now I am working alot with vectors in GRASS. For 
> instance I have a region that was created througha v.in.ogr. Now when I 
> bring in the coresponding raster maps they are verry blocky unless I 
> view them from a far out zoom. My region settings are
> 
> projection: 0 (x,y)
> zone:       0
> north:      44.86371257
> south:      44.67956501
> west:       -76.34802196
> east:       -76.08834984
> nsres:      0.00920738
> ewres:      0.01298361
> rows:       20
> cols:       20
> 
> I created a DEM from contour lines (v.surf.rst) and the results are 
> undesireable due to the chopyness of the raster. for instance instead of 
> smooth DEM I have lakes that contain one or two raster cells. The same 
> area would contain MANY contour lines. Cheers
> 
> A quick explanantion of what I've done and how to increase the 
> resolution of the rasters in my project would be appreciated.

Decrease the region resolution with "g.region res=..."; e.g. using
"g.region res=0.001" would give you roughly 200x200 rather than 20x20.

Any rasters which are created by GRASS are created at the current
resolution, so you will need to regenerate any rasters which were
created at too low a resolution.

This doesn't apply to rasters which are imported with r.in.*; they are
imported cell-for-cell.

-- 
Glynn Clements <glynn at gclements.plus.com>