r.stats.quantile - Compute category quantiles using two passes.

       Glynn Clements
       Markus Metz

r.stats.quantile is a tool to analyse exploratory statistics of a floating-point "cover layer"  according
       to how it intersects with objects in a "base layer". It provides quantile calculations as selected "zonal
       statistics".

       In  this  example,  the  raster  polygon  map  zipcodes  in  the North Carolina sample dataset is used to
       calculate quantile raster statistics using the elevation raster map:
       g.region raster=zipcodes -p
       # print quantiles
       r.stats.quantile base=zipcodes cover=elevation quantiles=3 -p
       27511:0:33.333333:134.717392
       27511:1:66.666667:143.985723
       27513:0:33.333333:140.669993
       27513:1:66.666667:146.279449
       27518:0:33.333333:115.140101
       27518:1:66.666667:129.893723
       [...]
       # write out percentile raster maps
       r.stats.quantile base=zipcodes cover=elevation percentiles=25,50,75 \
         output=zipcodes_elev_q25,zipcodes_elev_q50,zipcodes_elev_q75

       raster, statistics, zonal statistics, percentile, quantile

r.stats.quantile  - Compute category quantiles using two passes.

r.stats.quantile   is   intended  to  be  a  partial  replacement  for  r.statistics,  with  support  for
       floating-point cover maps. It provides quantile calculations, which are absent from r.stats.zonal.

       Quantiles are calculated following algorithm 7 from Hyndman and Fan (1996), which is also the default  in
       R and numpy.

           •   Hyndman and Fan (1996) SampleQuantilesinStatisticalPackages, AmericanStatistician.  American
               Statistical Association. 50 (4): 361-365. DOI: 10.2307/2684934

           •   EngineeringStatisticsHandbook:Percentile, NIST

r.quantile,r.stats.zonal,r.statistics

       Available at: r.stats.quantile source code (history)

       Accessed: Friday Apr 04 01:19:35 2025

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       © 2003-2025 GRASS Development Team, GRASS GIS 8.4.1 Reference Manual

GRASS 8.4.1                                                                             r.stats.quantile(1grass)

r.stats.quantiler.stats.quantile--helpr.stats.quantile   [-rpt]  base=namecover=name   [quantiles=integer]    [percentiles=float[,float,...]]
       [bins=integer]   [output=name[,name,...]]   [file=name]   [separator=character]   [--overwrite]  [--help]
       [--verbose]  [--quiet]  [--ui]

   Flags:-r
           Create reclass map with statistics as category labels

       -p
           Do not create output maps; just print statistics

       -t
           Print statistics in table format

       --overwrite
           Allow output files to overwrite existing files

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:base=name[required]
           Name of base raster map

       cover=name[required]
           Name of cover raster map

       quantiles=integer
           Number of quantiles

       percentiles=float[,float,...]
           List of percentiles
           Default: 50bins=integer
           Number of bins to use
           Default: 1000output=name[,name,...]
           Resultant raster map(s)

       file=name
           Name for output file (if omitted or "-" output to stdout)

       separator=character
           Field separator
           Special characters: pipe, comma, space, tab, newline
           Default: :