.TH r.statistics 1grass "" "GRASS 8.3.2" "GRASS GIS User's Manual"
.SH NAME
\fI\fBr.statistics\fR\fR  \- Calculates category or object oriented statistics.
.SH KEYWORDS
raster, statistics, zonal statistics
.SH SYNOPSIS
\fBr.statistics\fR
.br
\fBr.statistics \-\-help\fR
.br
\fBr.statistics\fR [\-\fBc\fR] \fBbase\fR=\fIname\fR \fBcover\fR=\fIname\fR \fBmethod\fR=\fIstring\fR \fBoutput\fR=\fIname\fR  [\-\-\fBoverwrite\fR]  [\-\-\fBhelp\fR]  [\-\-\fBverbose\fR]  [\-\-\fBquiet\fR]  [\-\-\fBui\fR]
.SS Flags:
.IP "\fB\-c\fR" 4m
.br
Cover values extracted from the category labels of the cover map
.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 "\fBmethod\fR=\fIstring\fR \fB[required]\fR" 4m
.br
Method of object\-based statistic
.br
Options: \fIdiversity, average, mode, median, avedev, stddev, variance, skewness, kurtosis, min, max, sum\fR
.br
\fBdiversity\fR: Diversity of values in specified objects in %%
.br
\fBaverage\fR: Average of values in specified objects
.br
\fBmode\fR: Mode of values in specified objects
.br
\fBmedian\fR: Median of values in specified objects
.br
\fBavedev\fR: Average deviation of values in specified objects
.br
\fBstddev\fR: Standard deviation of values in specified objects
.br
\fBvariance\fR: Variance of values in specified objects
.br
\fBskewness\fR: Skewnes of values in specified objects
.br
\fBkurtosis\fR: Kurtosis of values in specified objects
.br
\fBmin\fR: Minimum of values in specified objects
.br
\fBmax\fR: Maximum of values in specified objects
.br
\fBsum\fR: Sum of values in specified objects
.IP "\fBoutput\fR=\fIname\fR \fB[required]\fR" 4m
.br
Resultant raster map
.SH DESCRIPTION
\fIr.statistics\fR is a tool to analyse exploratory statistics of a categorical
\(dqcover layer\(dq according to how it intersects with objects in a \(dqbase layer\(dq.  A
variety of standard statistical measures are possible (called \(dqzonal statistics\(dq
in some GIS).
All cells in the base layer are considered one object for the analysis.  For
some applications, one will first want to prepare the input data so that
all areas of contiguous cell category values in the base layer are uniquely
identified, which can be done with \fIr.clump\fR.
.br
The available methods are the following:
.RS 4n
.IP \(bu 4n
average deviation
.IP \(bu 4n
average
.IP \(bu 4n
diversity
.IP \(bu 4n
kurtosis
.IP \(bu 4n
maximum
.IP \(bu 4n
median
.IP \(bu 4n
minimum
.IP \(bu 4n
mode
.IP \(bu 4n
skewness
.IP \(bu 4n
standard deviation
.IP \(bu 4n
sum
.IP \(bu 4n
variance
.RE
The calculations will be performed on each area of data of the
cover layers which fall within each unique value, or category, of the base layer.
.PP
Setting the \fI\-c\fR flag the category labels of the covering raster
layer will be used.  This is nice to avoid the GRASS limitation to integer
in raster maps because using category values floating point numbers can be
stored.
.PP
All calculations create an output layer.  The output
layer is a reclassified version of the base layer with identical
category values, but modified category labels \- the results of the calculations
are stored in the category labels of the output layer.
.SH NOTES
For floating\-point cover map support, see the alternative
\fIr.stats.zonal\fR.
For quantile calculations with support for floating\-point cover maps, see the
alternative \fIr.stats.quantile\fR.
.SH EXAMPLES
Calculation of average elevation of each field in the Spearfish region:
.br
.nf
\fC
r.statistics base=fields cover=elevation.dem out=elevstats method=average
r.category elevstats
r.mapcalc \(dqfieldelev = @elevstats\(dq
r.univar fieldelev
\fR
.fi
.SH SEE ALSO
\fI
r.category,
r.clump,
r.mode,
r.mapcalc,
r.neighbors,
r.stats.quantile,
r.stats.zonal,
r.univar
\fR
.SH AUTHOR
Martin Schroeder, Geographisches Institut Heidelberg, Germany
.SH SOURCE CODE
.PP
Available at:
r.statistics source code
(history)
.PP
Accessed: Friday Mar 08 07:34:43 2024
.PP
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.PP
© 2003\-2024
GRASS Development Team,
GRASS GIS 8.3.2 Reference Manual