Provided by: grass-doc_6.4.3-3_all
NAME
v.normal - Tests for normality for points.
KEYWORDS
vector, statistics
SYNOPSIS
v.normal v.normal help v.normal [-rql] map=string tests=range[,range,...] column=string [--verbose] [--quiet] Flags: -r Use only points in current region -q Quiet -l lognormal --verbose Verbose module output --quiet Quiet module output Parameters: map=string point vector defining sample points tests=range[,range,...] Lists of tests (1-15): e.g. 1,3-8,13 column=string Attribute column
DESCRIPTION
v.normal computes tests of normality on vector points.
NOTES
The tests that v.normal performs are indexed below. The tests that are performed are specified by giving an index, ranges of indices, or multiple thereof. 1 Sample skewness and kurtosis 2 Geary's a-statistic and an approximate normal transformation 3 Extreme normal deviates 4 D'Agostino's D-statistic 5 Modified Kuiper V-statistic 6 Modified Watson U^2-statistic 7 Durbin's Exact Test (modified Kolmogorov) 8 Modified Anderson-Darling statistic 9 Modified Cramer-Von Mises W^2-statistic 10 Kolmogorov-Smirnov D-statistic (modified for normality testing) 11 Chi-Square test statistic (equal probability classes) and the number of degrees of freedom 12 Shapiro-Wilk W Test 13 Weisberg-Binghams W'' (similar to Shapiro-Francia's W') 14 Royston's extension of W for large samples 15 Kotz Separate-Families Test for Lognormality vs. Normality
EXAMPLE
v.random random n=200 v.db.addtable random col="elev double precision" v.what.rast random rast=elevation.10m col=elev v.normal random tests=1-3,14 col=elev computes the sample skewness and kurtosis, Geary's a-statistic and an approximate normal transformation, extreme normal deviates, and Royston's W for the random vector points.
SEE ALSO
v.univar
AUTHOR
James Darrell McCauley , when he was at: Agricultural Engineering Purdue University Last changed: $Date: 2011-11-08 03:29:50 -0800 (Tue, 08 Nov 2011) $ Full index © 2003-2013 GRASS Development Team