[GRASS-dev] [GRASS GIS] #2376: Add p-value for regression slope in r series

GRASS GIS trac at osgeo.org
Wed Jul 30 12:11:46 PDT 2014

#2376: Add p-value for regression slope in r series
 Reporter:  mastho                        |       Owner:  grass-dev@…              
     Type:  enhancement                   |      Status:  new                      
 Priority:  normal                        |   Milestone:  7.0.0                    
Component:  Raster                        |     Version:  svn-releasebranch70      
 Keywords:  r.series, p-value regression  |    Platform:  Unspecified              
      Cpu:  Unspecified                   |  

Comment(by mmetz):

 Replying to [comment:2 pvanbosgeo]:
 > You can calculate the p-value using the [python] scipy library

 Considering that you want to calculate a p value for each single pixel,
 the chances that you get randomly some very small p values increase with
 the number of pixels. You would need to correct for that, with Bonferroni
 or some method that escapes the iron claw of Bonferroni. In any case, all
 your p values will most probably become not significant after any method
 of correction for multiple testing.

 Therefore it is more appropriate to make prior assumptions about slope,
 intercept, and effect size, then judge the results according to these
 prior assumptions.

Ticket URL: <https://trac.osgeo.org/grass/ticket/2376#comment:3>
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