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I have found a nice paper about r.diversity extension. But I don't understand why... it returns me empty raster without errors.

I have tried to compute diversity on ndvi from spot6 image...

r.diversity --verbose --overwrite input=SPOT6_P_20151113@PERMANENT prefix=div_ size=3-11

a r.info on one of these readers give me 

r.info map=div__pielou_size_3@unsup_class                                       
 +----------------------------------------------------------------------------+
 | Map:      div__pielou_size_3@unsup_clas  Date: Wed Apr  5 17:55:41 2017    |
 | Mapset:   unsup_class                    Login of Creator: delaye          |
 | Location: spot                                                             |
 | DataBase: /home/delaye/Documents/futurSahel/grassDB                        |
 | Title:    div__pielou_size_3                                               |
 | Timestamp: none                                                            |
 |----------------------------------------------------------------------------|
 |                                                                            |
 |   Type of Map:  raster               Number of Categories: 0               |
 |   Data Type:    DCELL                                                      |
 |   Rows:         811                                                        |
 |   Columns:      825                                                        |
 |   Total Cells:  669075                                                     |
 |        Projection: UTM (zone 28)                                           |
 |            N: 1766650.21572733    S: 1765434.19215405   Res: 1.49941254    |
 |            E: 468559.15364472    W: 467321.45407192   Res: 1.50024191      |
 |   Range of data:    min = -nan  max = -nan                                 |
 |                                                                            |
 |   Data Description:                                                        |
 |    gnr par r.li.pielou                                                     |
 |                                                                            |
 |   Comments:                                                                |
 |    r.li.pielou --overwrite input="SPOT6_NDVI_20151113@unsup_class" conf\   |
 |    ig="conf_diversity_3" output="div__pielou_size_3"                       |
 |                                                                            |
 +----------------------------------------------------------------------------+

How it works ? Regarding the paper I don't need a conf file for r.li ...

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2
  • GRASS GIS manual: r.diversity
    – gene
    Commented Apr 6, 2017 at 14:47
  • Of course I have read the manual :-) but I don't interstate why all the raster results are empty.
    – delaye
    Commented Apr 6, 2017 at 16:43

1 Answer 1

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Finally, I have found the solution. I was working on the image in 16 bit. So after a r.rescale as 

r.rescale input=cut_LC82040492015257LGN00_B2.1@PERMANENT output=cut_LC82040492015257LGN00_B2.1.resc to=0,255

it works like a charm 

r.diversity input=cut_LC82040492015257LGN00_B8.1.resc@PERMANENT prefix=div size=3-13

pielou analyse

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