1r.stats.quantile(1)         GRASS GIS User's Manual        r.stats.quantile(1)
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NAME

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

9       raster, statistics, zonal statistics, percentile, quantile
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SYNOPSIS

12       r.stats.quantile
13       r.stats.quantile --help
14       r.stats.quantile   [-rpt]   base=name  cover=name   [quantiles=integer]
15       [percentiles=float[,float,...]]          [bins=integer]           [out‐
16       put=name[,name,...]]    [file=name]    [separator=character]   [--over‐
17       write]  [--help]  [--verbose]  [--quiet]  [--ui]
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19   Flags:
20       -r
21           Create reclass map with statistics as category labels
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23       -p
24           Do not create output maps; just print statistics
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26       -t
27           Print statistics in table format
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29       --overwrite
30           Allow output files to overwrite existing files
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32       --help
33           Print usage summary
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35       --verbose
36           Verbose module output
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38       --quiet
39           Quiet module output
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41       --ui
42           Force launching GUI dialog
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44   Parameters:
45       base=name [required]
46           Name of base raster map
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48       cover=name [required]
49           Name of cover raster map
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51       quantiles=integer
52           Number of quantiles
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54       percentiles=float[,float,...]
55           List of percentiles
56           Default: 50
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58       bins=integer
59           Number of bins to use
60           Default: 1000
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62       output=name[,name,...]
63           Resultant raster map(s)
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65       file=name
66           Name for output file (if omitted or "-" output to stdout)
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68       separator=character
69           Field separator
70           Special characters: pipe, comma, space, tab, newline
71           Default: :
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DESCRIPTION

74       r.stats.quantile is a tool  to  analyse  exploratory  statistics  of  a
75       floating-point  "cover  layer"  according to how it intersects with ob‐
76       jects in a "base layer". It provides quantile calculations as  selected
77       "zonal statistics".
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NOTES

80       r.stats.quantile  is intended to be a partial replacement for r.statis‐
81       tics, with support for floating-point cover maps. It provides  quantile
82       calculations, which are absent from r.stats.zonal.
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84       Quantiles  are  calculated  following  algorithm 7 from Hyndman and Fan
85       (1996), which is also the default in R and numpy.
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EXAMPLE

88       In this example, the raster polygon map zipcodes in the North  Carolina
89       sample  dataset  is  used to calculate quantile raster statistics using
90       the elevation raster map:
91       g.region raster=zipcodes -p
92       # print quantiles
93       r.stats.quantile base=zipcodes cover=elevation quantiles=3 -p
94       27511:0:33.333333:134.717392
95       27511:1:66.666667:143.985723
96       27513:0:33.333333:140.669993
97       27513:1:66.666667:146.279449
98       27518:0:33.333333:115.140101
99       27518:1:66.666667:129.893723
100       [...]
101       # write out percentile raster maps
102       r.stats.quantile base=zipcodes cover=elevation percentiles=25,50,75 \
103         output=zipcodes_elev_q25,zipcodes_elev_q50,zipcodes_elev_q75
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REFERENCES

106           •   Hyndman and Fan (1996) Sample Quantiles  in  Statistical  Pack‐
107               ages,  American Statistician. American Statistical Association.
108               50 (4): 361-365. DOI: 10.2307/2684934
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110           •   Engineering Statistics Handbook: Percentile, NIST
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SEE ALSO

113        r.quantile, r.stats.zonal, r.statistics
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AUTHORS

116       Glynn Clements
117       Markus Metz
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SOURCE CODE

120       Available at: r.stats.quantile source code (history)
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122       Accessed: Saturday Jan 21 21:15:13 2023
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124       Main index | Raster index | Topics index | Keywords index  |  Graphical
125       index | Full index
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127       © 2003-2023 GRASS Development Team, GRASS GIS 8.2.1 Reference Manual
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131GRASS 8.2.1                                                r.stats.quantile(1)