.TH r.stats.quantile 1grass "" "GRASS 8.3.2" "GRASS GIS User's Manual"
.SH NAME
\fI\fBr.stats.quantile\fR\fR  \- Compute category quantiles using two passes.
.SH KEYWORDS
raster, statistics, zonal statistics, percentile, quantile
.SH SYNOPSIS
\fBr.stats.quantile\fR
.br
\fBr.stats.quantile \-\-help\fR
.br
\fBr.stats.quantile\fR [\-\fBrpt\fR] \fBbase\fR=\fIname\fR \fBcover\fR=\fIname\fR  [\fBquantiles\fR=\fIinteger\fR]   [\fBpercentiles\fR=\fIfloat\fR[,\fIfloat\fR,...]]   [\fBbins\fR=\fIinteger\fR]   [\fBoutput\fR=\fIname\fR[,\fIname\fR,...]]   [\fBfile\fR=\fIname\fR]   [\fBseparator\fR=\fIcharacter\fR]   [\-\-\fBoverwrite\fR]  [\-\-\fBhelp\fR]  [\-\-\fBverbose\fR]  [\-\-\fBquiet\fR]  [\-\-\fBui\fR]
.SS Flags:
.IP "\fB\-r\fR" 4m
.br
Create reclass map with statistics as category labels
.IP "\fB\-p\fR" 4m
.br
Do not create output maps; just print statistics
.IP "\fB\-t\fR" 4m
.br
Print statistics in table format
.IP "\fB\-\-overwrite\fR" 4m
.br
Allow output files to overwrite existing files
.IP "\fB\-\-help\fR" 4m
.br
Print usage summary
.IP "\fB\-\-verbose\fR" 4m
.br
Verbose module output
.IP "\fB\-\-quiet\fR" 4m
.br
Quiet module output
.IP "\fB\-\-ui\fR" 4m
.br
Force launching GUI dialog
.SS Parameters:
.IP "\fBbase\fR=\fIname\fR \fB[required]\fR" 4m
.br
Name of base raster map
.IP "\fBcover\fR=\fIname\fR \fB[required]\fR" 4m
.br
Name of cover raster map
.IP "\fBquantiles\fR=\fIinteger\fR" 4m
.br
Number of quantiles
.IP "\fBpercentiles\fR=\fIfloat[,\fIfloat\fR,...]\fR" 4m
.br
List of percentiles
.br
Default: \fI50\fR
.IP "\fBbins\fR=\fIinteger\fR" 4m
.br
Number of bins to use
.br
Default: \fI1000\fR
.IP "\fBoutput\fR=\fIname[,\fIname\fR,...]\fR" 4m
.br
Resultant raster map(s)
.IP "\fBfile\fR=\fIname\fR" 4m
.br
Name for output file (if omitted or \(dq\-\(dq output to stdout)
.IP "\fBseparator\fR=\fIcharacter\fR" 4m
.br
Field separator
.br
Special characters: pipe, comma, space, tab, newline
.br
Default: \fI:\fR
.SH DESCRIPTION
\fIr.stats.quantile\fR is a tool to analyse exploratory statistics of a
floating\-point \(dqcover layer\(dq according to how it intersects with objects
in a \(dqbase layer\(dq. It provides quantile calculations as selected
\(dqzonal statistics\(dq.
.SH NOTES
\fIr.stats.quantile\fR is intended to be a partial replacement for
\fIr.statistics\fR, with support
for floating\-point cover maps. It provides quantile calculations,
which are absent from
\fIr.stats.zonal\fR.
.PP
Quantiles are calculated following algorithm 7 from Hyndman and Fan (1996),
which is also the default in R and numpy.
.SH EXAMPLE
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:
.br
.nf
\fC
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 \(rs
  output=zipcodes_elev_q25,zipcodes_elev_q50,zipcodes_elev_q75
\fR
.fi
.SH REFERENCES
.RS 4n
.IP \(bu 4n
Hyndman and Fan (1996) \fISample Quantiles in Statistical
Packages\fR, \fBAmerican Statistician\fR. American Statistical
Association. 50 (4): 361\-365. DOI: 10.2307/2684934
.IP \(bu 4n
\fIEngineering
Statistics Handbook: Percentile\fR, NIST
.RE
.SH SEE ALSO
\fI
r.quantile,
r.stats.zonal,
r.statistics
\fR
.SH AUTHORS
Glynn Clements
.br
Markus Metz
.SH SOURCE CODE
.PP
Available at:
r.stats.quantile source code
(history)
.PP
Accessed: Thursday Mar 07 18:15:22 2024
.PP
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.PP
© 2003\-2024
GRASS Development Team,
GRASS GIS 8.3.2 Reference Manual