[GRASSLIST:6531] resolution

[Maciek Sieczka]

Hi

I'm wondering why does it happen, that when the resolution is decreased 
(even if very slightly), some separate pixels dissapear on display. And when 
I continue decreasing res they re-appear, but some other dissapear again. 
What's more, it doesn't reffer to display only - also when 'r.mapcalc' is 
used the resulting layers miss the same pixels as on the display. Badly 
puzzling. I would rather expect these pixels only to grow but not to get 
gone for good. See attachments.



            figure "res10.png":

GRASS 6.1.cvs (kpn92):~ > g.region -p
projection: 99 (Transverse Mercator)
zone:       0
datum:      etrs89
ellipsoid:  grs80
north:      331740
south:      330480
west:       259580
east:       260800
nsres:      10
ewres:      10
rows:       126
cols:       122
GRASS 6.1.cvs (kpn92):~ > d.rast rozn2
 100%



            figure "res12.png":

GRASS 6.1.cvs (kpn92):~ > g.region res=12 -ap
projection: 99 (Transverse Mercator)
zone:       0
datum:      etrs89
ellipsoid:  grs80
north:      331752
south:      330468
west:       259548
east:       260820
nsres:      12
ewres:      12
rows:       107
cols:       106
GRASS 6.1.cvs (kpn92):~ > d.rast rozn2
 100%



            figure "res13.png"

GRASS 6.1.cvs (kpn92):~ > g.region res=13 -ap
projection: 99 (Transverse Mercator)
zone:       0
datum:      etrs89
ellipsoid:  grs80
north:      331760
south:      330460
west:       259545
east:       260832
nsres:      13
ewres:      13
rows:       100
cols:       99
GRASS 6.1.cvs (kpn92):~ > d.rast rozn2
 100%

Maciek 
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