1r.cross(1) Grass User's Manual r.cross(1)
2
6 r.cross - Creates a cross product of the category values from multiple
7 raster map layers.
8
10 raster, statistics
11
13 r.cross
14 r.cross --help
15 r.cross [-z] input=string[,string,...] output=name [--overwrite]
16 [--help] [--verbose] [--quiet] [--ui]
17 Flags:
19 -z
20 Non-zero data only
21 --overwrite
23 Allow output files to overwrite existing files
24 --help
26 Print usage summary
27 --verbose
29 Verbose module output
30 --quiet
32 Quiet module output
33 --ui
35 Force launching GUI dialog
36 Parameters:
38 input=string[,string,...] [required]
39 Names of 2-30 input raster maps
40 output=name [required]
42 Name for output raster map
43
45 r.cross creates an output raster map layer representing all unique com‐
46 binations of category values in the raster input layers
47 (input=name,name,name, ...). At least two, but not more than ten,
48 input map layers must be specified. The user must also specify a name
49 to be assigned to the output raster map layer created by r.cross.
50
52 The program will be run non-interactively if the user specifies the
53 names of between 2-10 raster map layers be used as input, and the name
54 of a raster map layer to hold program output.
55 With the -z flag zero data values are not crossed. This means that if
57 a zero category value occurs in any input data layer, the combination
58 is assigned to category zero in the resulting map layer, even if other
59 data layers contain non-zero data. In the example given above, use of
60 the -z option would cause 3 categories to be generated instead of 5.
61 If the -z flag is not specified, then map layer combinations in which
63 not all category values are zero will be assigned a unique category
64 value in the resulting map layer.
65 Category values in the new output map layer will be the cross-product
67 of the category values from these existing input map layers.
68
70 For example, suppose that, using two raster map layers, the following
71 combinations occur:
72 map1 map2
73 ___________
74 0 1
75 0 2
76 1 1
77 1 2
78 2 4
79 r.cross would produce a new raster map layer with 5 categories:
80 map1 map2 output
81 ____________________
82 0 1 1
83 0 2 2
84 1 1 3
85 1 2 4
86 2 4 5
87 Note: The actual category value assigned to a particular combination in
88 the result map layer is dependent on the order in which the combina‐
89 tions occur in the input map layer data and can be considered essen‐
90 tially random. The example given here is illustrative only.
91
93 The category file created for the output raster map layer describes the
94 combinations of input map layer category values which generated each
95 category. In the above example, the category labels would be:
96 category category
97 value label
98 ______________________________
99 1 layer1(0) layer2(1)
100 2 layer1(0) layer2(2)
101 3 layer1(1) layer2(1)
102 4 layer1(1) layer2(2)
103 5 layer1(2) layer2(4)
104 A random color table is also generated for the output map layer.
105
107 r.covar, r.stats
108
110 Michael Shapiro, U.S. Army Construction Engineering Research Laboratory
111 Last changed: $Date: 2016-01-28 12:21:34 +0100 (Thu, 28 Jan 2016) $
113
115 Available at: r.cross source code (history)
116 Main index | Raster index | Topics index | Keywords index | Graphical
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119 © 2003-2019 GRASS Development Team, GRASS GIS 7.4.4 Reference Manual
121GRASS 7.4.4 r.cross(1)