[GRASS-user] r.mapcalc on rasters with different resolutions and origin

[Enrico Gallo]

Dear list,

I would like to use r.mapcalc in order to compare 2 different resolution
floating-point raster (A = 1km and B = 100 m) and to calculate some
statistics on the finest resolution map ( so g.region res=100)

As the two layers have different resolution and origin, some doubts arise :

does r.mapcalc use *nearest neighbour* to perform calculation?
is a resample using *r.resamp.interp* (bilinear or cubist) suggested/needed
before running r.mapcalc?


arcgis manual  about map argebra says:
"For the floating-point input rasters of different resolution it is
recommended to RESAMPLE all the data using BILINEAR interpolation or CUBIC
convolution before running Merge. Otherwise, the Merge function will
automatically resample the rasters using NEAREST neighbor (which is not
appropriate for the continuous type of data)

I was not able to find this kind of recommendation in mapcalc help or wiki
page  ... Am I missing something?

thanks

Enrico
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/grass-user/attachments/20110722/9fb5e78e/attachment-0001.html