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

[GRASS GIS]

#1401: r.series for time series
---------------------------------+------------------------------------------
 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                  |  
---------------------------------+------------------------------------------

Comment(by glynn):

 Replying to [comment:5 mmetz]:

 > I will try to explain the motivation for this patch with an example.

 Okay, so you're filtering in the time domain, then taking a single sample
 from the middle of the interval?

 Even so, I would suggest making the "radius" (i.e. cut-off frequency) a
 parameter, and probably also the centre (although that can be fudged by
 padding with null maps).

 In general, the cut-off frequency shouldn't depend upon the filtering
 method; the reason the various filters in r.resamp.filter have associated
 radii is so that the cut-off frequency doesn't vary with the filter method
 (i.e. the user-supplied radius value is normalised).

 Also, if you're likely to want more than one output, extending r.series to
 support multiple outputs (with different offsets) would be significantly
 more efficient than multiple runs of r.series (reading the inputs could
 easily take more time than the actual processing).

-- 
Ticket URL: <https://trac.osgeo.org/grass/ticket/1401#comment:6>
GRASS GIS <http://grass.osgeo.org>