Cell referencing

Michael Shapiro shapiro at zorro.cecer.army.mil
Thu Jun 18 15:23:42 EDT 1992

If you are talking about the region edges (of cell header edges)
[north, south, east, west], they refer to the edges of the cell, not
the center.  Ie, the north value refers to the top edge of the first
row of cells, west refers to the left edge of the first column of
cells, etc.

If you are refering to how GRASS "resamples" a raster map into the
current region, it is neareast neighbor resampling: the geographic
coordinates of hte center of the a given cell in the region is used to
find the corresponding cell in the raster map.

This logic has not changed at all with various releases of GRASS.

|I am a relatively new grass user and need to know about how grass refrences it's cells.  
|I was told that they are referenced by the centers and not their edges, therefore everything 
|would be shifted.  Is this true, or was this true of the versions earlier than GRASS 4.0? 
|Leah Lewis 


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