[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 glynn):

 Replying to [ticket:1401 mmetz]:

 > The attached patch adds weighing windows to r.series

 A few points:

 1. This patch places the centre of the window in the centre of the time
 period; I would have expected this to be configurable. E.g. I can imagine
 situations where the most recent data would have the greatest weight, with
 weight decreasing as the data gets older. Unlike spatial data, time has an
 inherent asymmetry between past and future.

 2. I don't see the stated modifications to the gauss/normal or sinc
 functions. They appear to be identical to the r.series versions. Also, I'm
 not sure why those modifications would make sense; e.g. the fact that
 sinc/lanczos have negative weights is one of their advantages, as it
 results in sharper output than filters with only positive weights.

 3. Is "radius" really the correct term for one-dimensional data?

 Possible enhancements:

 Allowing arbitrary weights (one per input map) to be read from a file
 and/or a command line option.

 Accepting a list of weight maps (one per input map), i.e. each input cell
 is a value/weight pair rather than just a value.

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Ticket URL: <https://trac.osgeo.org/grass/ticket/1401#comment:1>
GRASS GIS <http://grass.osgeo.org>