[GRASS-dev] [bug #3729] (grass) g.region zoom= off by one error on eastern side

GRASS GIS GRASS GIS developer
1

Also, the issue is much worse than your example suggests. Because col
is one too high, the loop never examines the rightmost column.
Consider:

  $ g.region -a n=4916070 s=4915800 w=602940 e=603240 res=30
  $ r.mapcalc 'map1 = if(col() == 1 || col() == 10,1,null())'
  $ g.region -a n=4916250 s=4915620 w=602730 e=603450 res=30
  $ g.region rast=map1
  $ g.region zoom=map1
  $ g.region -p
  projection: 1 (UTM)
  zone: 13
  datum: nad27
  ellipsoid: clark66
  north: 4916070
  south: 4915800
  west: 602940
  east: 603000
  nsres: 30
  ewres: 30
  rows: 9
***> cols: 2
  cells: 18

Thus, "g.region zoom=..." can actually make the region too small,
discarding valid data.

Glynn,

Sorry for being slow - does your fix take care of that also?

Maciek

-------------------------------------------- Managed by Request Tracker

2

Maciek Sieczka via RT wrote:

> Also, the issue is much worse than your example suggests. Because col
> is one too high, the loop never examines the rightmost column.
> Consider:

[snip]

> Thus, "g.region zoom=..." can actually make the region too small,
> discarding valid data.

Sorry for being slow - does your fix take care of that also?

Yes.

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