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<h2>DESCRIPTION</h2>
<p><em>r.resamp.filter</em> resamples an input raster, filtering the
input with an analytic kernel.
<p>All of the kernels specified by the filter= option are multiplied
together. Typical usage will use either a single kernel or an infinite
kernel along with a finite window.
<h2>NOTES</h2>
<p>Resampling modules (<em>r.resample, r.resamp.stats, r.resamp.interp,
r.resamp.rst, r.resamp.filter</em>) resample the map to match the
current region settings.
<p>When using a kernel which can have negative values (sinc, Lanczos),
the <em>-n</em> flag should be used. Otherwise, extreme values can
arise due to the total weight being close (or even equal) to zero.
<p>Kernels with infinite extent (Gauss, normal, sinc, Hann, Hamming,
Blackman) must be used in conjunction with a finite windowing function
(box, Bartlett, Hermite, Lanczos)
<p>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.
<h2>SEE ALSO</h2>
<em><a href="g.region.html">g.region</a></em>,
<em><a href="r.resample.html">r.resample</a></em>,
<em><a href="r.resamp.rst.html">r.resamp.rst</a></em>
<em><a href="r.resamp.stats.html">r.resamp.stats</a></em>
<h2>AUTHOR</h2>
Glynn Clements
<p><i>Last changed: $Date: 2011-11-08 13:24:20 -0800 (Tue, 08 Nov 2011) $</i>
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