1r.kappa(1) Grass User's Manual r.kappa(1)
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6 r.kappa - Calculate error matrix and kappa parameter for accuracy
7 assessment of classification result.
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10 raster
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13 r.kappa
14 r.kappa help
15 r.kappa [-wqh] classification=string reference=string [output=string]
16 [title=string]
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18 Flags:
19 -w wide report, 132 columns (default: 80)
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21 -q quiet
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23 -h no header in the report
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25 Parameters:
26 classification=string
27 File name of classification result
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29 reference=string
30 File name of reference classes
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32 output=string
33 Name of an output file containing of error matrix and kappa
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35 title=string
36 Title for error matrix and kappa Default: ACCURACY ASSESSMENT
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39 r.kappa tabulates the error matrix of classification result by crossing
40 classified map layer with respect to reference map layer. Both overall
41 kappa (accompanied by its variance) and conditional kappa values are
42 calculated. This analysis program respects the current geographic
43 region and mask settings.
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45 r.kappa calculates the error matrix of the two map layers and prepares
46 the table from which the report is to be created. kappa values for
47 overall and each classes are computed along with their variances. Also
48 percent of commission and ommission error, total correct classified
49 result by pixel counts, total area in pixel counts and percentage of
50 overall correctly classified pixels are tabulated.
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52 The report will be write to an output file which is in plain text for‐
53 mat and named by user at prompt of running the program.
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55 The body of the report is arranged in panels. The classified result
56 map layer categories is arranged along the vertical axis of the table,
57 while the reference map layer categories along the horizontal axis.
58 Each panel has a maximum of 5 categories (9 if wide format) across the
59 top. In addition, the last column of the last panel reflects a cross
60 total of each column for each row. All of the categories of the map
61 layer arranged along the vertical axis, i.e., the reference map layer,
62 are included in each panel. There is a total at the bottom of each
63 column representing the sum of all the rows in that column.
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66 It is recommended to reclassify categories of classified result map
67 layer into a more manageable number before running r.kappa on the clas‐
68 sified raster map layer. Because r.kappa calculates and then reports
69 information for each and every category.
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71 NA's in output file mean non-applicable in case MASK exists.
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74 g.region, m.ipf, r.cats, r.reclass, r.report, r.stats
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77 Tao Wen, University of Illinois at Urbana-Champaign, Illinois
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79 Last changed: $Date: 2006/04/13 19:01:37 $
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81 Full index
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85GRASS 6.2.2 r.kappa(1)