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.

```

#### SEEALSO

```       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) \$

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© 2003-2013 GRASS Development Team
```