.TH v.normal 1grass "" "GRASS 6.4.4" "Grass User's Manual"
.SH NAME
\fI\fBv.normal\fR\fR  - Tests for normality for points.
.SH KEYWORDS
vector, statistics
.SH SYNOPSIS
\fBv.normal\fR
.br
\fBv.normal help\fR
.br
\fBv.normal\fR [\-\fBrql\fR] \fBmap\fR=\fIstring\fR \fBtests\fR=\fIrange\fR[,\fIrange\fR,...] \fBcolumn\fR=\fIstring\fR  [\-\-\fBverbose\fR]  [\-\-\fBquiet\fR] 
.SS Flags:
.IP "\fB\-r\fR" 4m
.br
Use only points in current region
.IP "\fB\-q\fR" 4m
.br
Quiet
.IP "\fB\-l\fR" 4m
.br
lognormal
.IP "\fB\-\-verbose\fR" 4m
.br
Verbose module output
.IP "\fB\-\-quiet\fR" 4m
.br
Quiet module output
.PP
.SS Parameters:
.IP "\fBmap\fR=\fIstring\fR" 4m
.br
point vector defining sample points
.IP "\fBtests\fR=\fIrange[,\fIrange\fR,...]\fR" 4m
.br
Lists of tests (1-15): e.g. 1,3-8,13
.IP "\fBcolumn\fR=\fIstring\fR" 4m
.br
Attribute column
.PP
.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's a-statistic and an approximate normal transformation
.IP \fB3\fR
 Extreme normal deviates
.IP \fB4\fR
 D'Agostino's D-statistic 
.IP \fB5\fR
 Modified Kuiper V-statistic 
.IP \fB6\fR
 Modified Watson U^2-statistic 
.IP \fB7\fR
 Durbin's 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'' (similar to Shapiro-Francia's W')
.IP \fB14\fR
 Royston's extension of W for large samples
.IP \fB15\fR
 Kotz Separate-Families Test for Lognormality vs. Normality
.PP
.SH EXAMPLE
\fC
.DS
.br
v.random random n=200
.br
v.db.addtable random col="elev double precision"
.br
v.what.rast random rast=elevation.10m col=elev
.br
v.normal random tests=1-3,14 col=elev
.br
.DE
\fR
computes the sample skewness and kurtosis, Geary's
a-statistic and an approximate normal transformation,
extreme normal deviates, and Royston's W for the
\fIrandom\fR vector points.
.SH SEE ALSO
v.univar
.SH AUTHOR
James Darrell McCauley
,
.br
when he was at:
Agricultural
Engineering
Purdue University
.PP
\fILast changed: $Date: 2011-11-08 12:29:50 +0100 (Tue, 08 Nov 2011) $\fR
.PP
Full index
.PP
© 2003-2014 GRASS Development Team