NAMEr.resamp.interp - Resamples raster map layers to a finer grid using interpolation.
SYNOPSISr.resamp.interp r.resamp.interp help r.resamp.interp input=name output=name [method=string] [--overwrite] [--verbose] [--quiet] Flags: --overwrite Allow output files to overwrite existing files --verbose Verbose module output --quiet Quiet module output Parameters: input=name Name of input raster map output=name Name for output raster map method=string Interpolation method Options: nearest,bilinear,bicubic Default: bilinear
DESCRIPTIONr.resamp.interp resamples an input raster map by interpolating between the neighboring cells via a selectable resampling algorithm. All cells present in the neighborhood of the input raster cell must be non-null to generate a non-null cell in the output raster map. A choice of three interpolation methods is available; each uses the weighted values of a different number of adjacent cells in the input map to determine the value of each cell in the output map as follows: nearest neighbour (1 cell) bilinear (4 cells) bicubic (16 cells) This module is intended for reinterpolation of continuous data to a different resolution rather than for interpolation from scattered data (use the v.surf.* modules for that purpose).
NOTESResampling modules (r.resample, r.resamp.stats, r.resamp.interp, r.resamp.rst) resample the map to match the current region settings. Note that for bilinear and bicubic interpolation, cells of the output raster that cannot be bounded by the appropriate number of input cell centers are set to NULL (NULL propagation). This could occur due to the input cells being outside the current region, being NULL or MASKed. For longitude-latitude locations, the interpolation algorithm is based on degree fractions, not on the absolute distances between cell centers. Any attempt to implement the latter would violate the integrity of the interpolation method.
EXAMPLEResample elevation raster map to a higher resolution (from 500m to 250m; North Carolina sample dataset): g.region rast=elev_state_500m -p g.region res=250 -ap r.resamp.interp input=elev_state_500m output=elev_state_250m
SEE ALSOg.region, r.resample, r.resamp.rst r.resamp.stats
AUTHORGlynn Clements Last changed: $Date: 2010-01-17 00:46:53 +0100 (Sun, 17 Jan 2010) $ Full index (C) 2003-2010 GRASS Development Team R.RESAMP.INTERP(1)