1v.normal(1) GRASS GIS User's Manual v.normal(1)
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6 v.normal - Tests for normality for vector points.
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9 vector, statistics, points, point pattern
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12 v.normal
13 v.normal --help
14 v.normal [-rl] map=name [layer=string] tests=range[,range,...] col‐
15 umn=name [--help] [--verbose] [--quiet] [--ui]
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17 Flags:
18 -r
19 Use only points in current region
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21 -l
22 Lognormality instead of normality
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24 --help
25 Print usage summary
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27 --verbose
28 Verbose module output
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30 --quiet
31 Quiet module output
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33 --ui
34 Force launching GUI dialog
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36 Parameters:
37 map=name [required]
38 Name of vector map
39 Or data source for direct OGR access
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41 layer=string
42 Layer number or name
43 Vector features can have category values in different layers. This
44 number determines which layer to use. When used with direct OGR ac‐
45 cess this is the layer name.
46 Default: 1
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48 tests=range[,range,...]Â [required]
49 Lists of tests (1-15)
50 E.g. 1,3-8,13
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52 column=name [required]
53 Name of attribute column
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56 v.normal computes tests of normality on vector points.
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59 The tests that v.normal performs are indexed below. The tests that are
60 performed are specified by giving an index, ranges of indices, or mul‐
61 tiple thereof.
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63 1 Sample skewness and kurtosis
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65 2 Geary’s a-statistic and an approximate normal transformation
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67 3 Extreme normal deviates
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69 4 D’Agostino’s D-statistic
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71 5 Modified Kuiper V-statistic
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73 6 Modified Watson U^2-statistic
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75 7 Durbin’s Exact Test (modified Kolmogorov)
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77 8 Modified Anderson-Darling statistic
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79 9 Modified Cramer-Von Mises W^2-statistic
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81 10 Kolmogorov-Smirnov D-statistic (modified for normality testing)
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83 11 Chi-Square test statistic (equal probability classes) and the
84 number of degrees of freedom
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86 12 Shapiro-Wilk W Test
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88 13 Weisberg-Binghams W’’ (similar to Shapiro-Francia’s W’)
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90 14 Royston’s extension of W for large samples
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92 15 Kotz Separate-Families Test for Lognormality vs. Normality
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95 Compute the sample skewness and kurtosis, Geary’s a-statistic and an
96 approximate normal transformation, extreme normal deviates, and Roys‐
97 ton’s W for the random vector points:
98 g.region raster=elevation -p
99 v.random random n=200
100 v.db.addtable random column="elev double precision"
101 v.what.rast random rast=elevation column=elev
102 v.normal random tests=1-3,14 column=elev
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105 v.univar
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108 James Darrell McCauley <darrell@mccauley-usa.com>,
109 when he was at: Agricultural Engineering Purdue University
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112 Available at: v.normal source code (history)
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114 Accessed: Saturday Jan 21 21:16:13 2023
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116 Main index | Vector index | Topics index | Keywords index | Graphical
117 index | Full index
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119 © 2003-2023 GRASS Development Team, GRASS GIS 8.2.1 Reference Manual
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123GRASS 8.2.1 v.normal(1)