[GRASS-dev] Re: [GRASS GIS] #1401: r.series for time series

[GRASS GIS]

#1401: r.series for time series
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 Reporter:  mmetz                |       Owner:  grass-dev@…              
     Type:  enhancement          |      Status:  new                      
 Priority:  normal               |   Milestone:  7.0.0                    
Component:  Raster               |     Version:  svn-trunk                
 Keywords:  raster, time series  |    Platform:  All                      
      Cpu:  All                  |  
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Comment(by mmetz):

 Replying to [comment:8 glynn]:
 > Replying to [comment:7 mmetz]:
 >
 > > The way I currently use the patched r.series, an option radius would
 only make sense in combination with a multiple option centre.
 >
 > It would make sense even for a single output, as it controls how rapidly
 the weight falls off with distance from the centre.
 >

 I was reading up a bit and thinking about it. As I understand it, the
 fundamental difference between r.resamp.filter and the patched r.series is
 that for r.resamp.filter, the window size is a function of the user-given
 radius and the chosen (combination of) filtering window(s), whereas for
 r.series, the radius is a function of the chosen window size (number of
 input maps) and the filtering window. The reason for my implementation is
 a simpler user-interface. Otherwise, i.e. with a required option radius,
 warning/error messages are needed if the number of input maps exceeds or
 is smaller than the window size. And I wanted an easy way to test various
 filters with differing sharpness (e.g. lanczos1 vs. lanczos3) using the
 same window size.

 In short, I think that a user-controlled window size results in a simpler
 user-interface, but an option radius would make the patch more versatile
 and is more in line with the concept of FIR filtering.

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Ticket URL: <https://trac.osgeo.org/grass/ticket/1401#comment:9>
GRASS GIS <http://grass.osgeo.org>