1r3.stats(1) GRASS GIS User's Manual r3.stats(1)
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6 r3.stats - Generates volume statistics for 3D raster maps.
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9 raster3d, statistics, voxel, volume
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12 r3.stats
13 r3.stats --help
14 r3.stats [-ec] input=name [nsteps=integer] [--help] [--verbose]
15 [--quiet] [--ui]
16 Flags:
18 -e
19 Calculate statistics based on equal value groups
20 -c
22 Only print cell counts
23 --help
25 Print usage summary
26 --verbose
28 Verbose module output
29 --quiet
31 Quiet module output
32 --ui
34 Force launching GUI dialog
35 Parameters:
37 input=name [required]
38 Name of input 3D raster map
39 nsteps=integer
41 Number of subranges to collect stats from
42 Default: 20
43
45 r3.stats calculates volume statistics for 3D raster maps. Volumes are
46 created on base of value subranges or groups of equal values. The
47 default number of subranges is 20 and can vary from 1 to infinite.
48 Larger number of subranges will result in larger memory consumption.
49 The volumes are calculated in qubic meters. Null values are marked with
50 "*". If the flag -e is set, the number of subranges will be ignored.
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53 As with most GRASS 3D raster map modules, r3.stats operates on the cell
54 array defined by the current 3D region settings, not the original
55 extent and resolution of the input map. See g.region.
56 The region setting will not effect the memory consumption of this mod‐
58 ule. The number of subranges in case of value range calculation or the
59 number of equal value groups effect the memory consumption and the cal‐
60 culation time. The user can expect a huge time consumption to calcu‐
61 late the equal value groups (flag -e) if large region settings occur
62 for maps which have many equal value groups (> 100000).
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65 Lausanne FOSS4G 2006 3D demo dataset example
66 The 3D raster map geology has three values. Each value represents a
67 specific geological layer, clay = 1, sand = 2 and bedrock = 3. To cal‐
68 culate the volume of each geological layer, we can use the flag -e to
69 group equal values into single volumes. r3.stats geology -e will pro‐
70 duce the following output:
71 num | value | volume | perc | count
73 1 1.000000 300822000.000 50.13700 50137
74 2 2.000000 101400000.000 16.90000 16900
75 3 3.000000 197778000.000 32.96300 32963
76 4 * 0.000 0.00000 0
77 Number of groups with equal values: 3
78 Sum of non Null cells:
79 Volume = 600000000.000
80 Percentage = 100.000
81 Count = 100000
82 Sum of all cells:
83 Volume = 600000000.000
84 Percentage = 100.000
85 Count = 100000
86 Generic example
88 #create a small 3D region
89 g.region n=1000 s=0 e=2000 w=0 t=300 b=0 res3=100
90 #create a raster3D map with row() and null values
91 r3.mapcalc "volmap = if(row() == 5, null(), row())"
92 #run r3.stats with a subrange of 10
93 r3.stats input=volmap nsteps=10
94 #the result should look like this
95 num | minimum <= value | value < maximum | volume | perc | cell count
96 1 1.000000000 1.900000000 60000000.000 10.00000 60
97 2 1.900000000 2.800000000 60000000.000 10.00000 60
98 3 2.800000000 3.700000000 60000000.000 10.00000 60
99 4 3.700000000 4.600000000 60000000.000 10.00000 60
100 5 4.600000000 5.500000000 0.000 0.00000 0
101 6 5.500000000 6.400000000 60000000.000 10.00000 60
102 7 6.400000000 7.300000000 60000000.000 10.00000 60
103 8 7.300000000 8.200000000 60000000.000 10.00000 60
104 9 8.200000000 9.100000000 60000000.000 10.00000 60
105 10 9.100000000 10.000000001 60000000.000 10.00000 60
106 11 * * 60000000.000 10.00000 60
107 Sum of non Null cells:
108 Volume = 540000000.000
109 Percentage = 90.000
110 Cell count = 540
111 Sum of all cells:
112 Volume = 600000000.000
113 Percentage = 100.000
114 Cell count = 600
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117 g.region, r3.univar, r.stats, r.statistics, v.univar
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120 Sören Gebbert
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123 Available at: r3.stats source code (history)
124 Main index | 3D raster index | Topics index | Keywords index | Graphi‐
126 cal index | Full index
127 © 2003-2020 GRASS Development Team, GRASS GIS 7.8.5 Reference Manual
129GRASS 7.8.5 r3.stats(1)