[GRASS5] r.mapcalc: Neighborhood cell index
Roger.Bivand at nhh.no
Tue Feb 18 06:04:16 EST 2003
On Tue, 18 Feb 2003, Markus Neteler wrote:
> Dear developers,
> a question related to r.mapcalc's scheme of neighborhood cell index:
> In Larson, Shapiro, Tweddale, 1991, "Performing Map Calculations on GRASS
> Data: r.mapcalc Programa Tutorial", 3.5. Neighborhood modifiers, p.8.
> is written:
> "format is map[r,c],..."
> "map[1,2] refers to one row below and two columns to the right..."
> That means:
> map[y,x] with x positive to "East" and y positive to "South".
> For curiousity: Is there a particular reason to have the orientation
> pointing positive to South?
Because rows start at 0 at the northern edge? Then the n/s offsets would
work without reversal?
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e-mail: Roger.Bivand at nhh.no
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