.TH v.normal 1grass "" "GRASS 7.8.5" "GRASS GIS User's Manual"
.SH NAME
\fI\fBv.normal\fR\fR  \- Tests for normality for vector points.
.SH KEYWORDS
vector, statistics, points, point pattern
.SH SYNOPSIS
\fBv.normal\fR
.br
\fBv.normal \-\-help\fR
.br
\fBv.normal\fR [\-\fBrl\fR] \fBmap\fR=\fIname\fR  [\fBlayer\fR=\fIstring\fR]  \fBtests\fR=\fIrange\fR[,\fIrange\fR,...] \fBcolumn\fR=\fIname\fR  [\-\-\fBhelp\fR]  [\-\-\fBverbose\fR]  [\-\-\fBquiet\fR]  [\-\-\fBui\fR]
.SS Flags:
.IP "\fB\-r\fR" 4m
.br
Use only points in current region
.IP "\fB\-l\fR" 4m
.br
Lognormality instead of normality
.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 "\fBmap\fR=\fIname\fR \fB[required]\fR" 4m
.br
Name of vector map
.br
Or data source for direct OGR access
.IP "\fBlayer\fR=\fIstring\fR" 4m
.br
Layer number or name
.br
Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name.
.br
Default: \fI1\fR
.IP "\fBtests\fR=\fIrange[,\fIrange\fR,...]\fR \fB[required]\fR" 4m
.br
Lists of tests (1\-15)
.br
E.g. 1,3\-8,13
.IP "\fBcolumn\fR=\fIname\fR \fB[required]\fR" 4m
.br
Name of attribute column
.SH DESCRIPTION
\fIv.normal\fR
computes tests of normality on vector points.
.SH NOTES
The tests that \fIv.normal\fR performs are indexed
below.  The tests that are performed are specified by
giving an index, ranges of indices, or multiple thereof.
.IP
.IP \fB1\fR
Sample skewness and kurtosis
.IP \fB2\fR
Geary\(cqs a\-statistic and an approximate normal transformation
.IP \fB3\fR
Extreme normal deviates
.IP \fB4\fR
D\(cqAgostino\(cqs D\-statistic
.IP \fB5\fR
Modified Kuiper V\-statistic
.IP \fB6\fR
Modified Watson U^2\-statistic
.IP \fB7\fR
Durbin\(cqs Exact Test (modified Kolmogorov)
.IP \fB8\fR
Modified Anderson\-Darling statistic
.IP \fB9\fR
Modified Cramer\-Von Mises W^2\-statistic
.IP \fB10\fR
Kolmogorov\-Smirnov D\-statistic (modified for normality testing)
.IP \fB11\fR
Chi\-Square test statistic (equal probability classes) and
the number of degrees of freedom
.IP \fB12\fR
Shapiro\-Wilk W Test
.IP \fB13\fR
Weisberg\-Binghams W\(cq\(cq (similar to Shapiro\-Francia\(cqs W\(cq)
.IP \fB14\fR
Royston\(cqs extension of W for large samples
.IP \fB15\fR
Kotz Separate\-Families Test for Lognormality vs. Normality
.PP
.SH EXAMPLE
Compute the sample skewness and kurtosis, Geary\(cqs
a\-statistic and an approximate normal transformation,
extreme normal deviates, and Royston\(cqs W for the
\fIrandom\fR vector points:
.br
.nf
\fC
g.region raster=elevation \-p
v.random random n=200
v.db.addtable random column=\(dqelev double precision\(dq
v.what.rast random rast=elevation column=elev
v.normal random tests=1\-3,14 column=elev
\fR
.fi
.SH SEE ALSO
\fI
v.univar
\fR
.SH AUTHOR
James Darrell McCauley
<darrell@mccauley\-usa.com>,
.br
when he was at:
Agricultural Engineering
Purdue University
.SH SOURCE CODE
.PP
Available at: v.normal source code (history)
.PP
Main index |
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Topics index |
Keywords index |
Graphical index |
Full index
.PP
© 2003\-2020
GRASS Development Team,
GRASS GIS 7.8.5 Reference Manual