1r.patch(1) Grass User's Manual r.patch(1)
2
6 r.patch - Creates a composite raster map layer by using known category
7 values from one (or more) map layer(s) to fill in areas of "no data" in
8 another map layer.
9
11 raster
12
14 r.patch
15 r.patch help
16 r.patch [-qz] input=string[,string,...] output=string [--overwrite]
17 Flags:
19 -q Quiet
20 -z Use zero (0) for transparency instead of NULL
22 --overwrite
24 Parameters:
26 input=string[,string,...]
27 Name of raster maps to be patched together
28 output=string
30 Name of the resultant map
31
33 The GRASS program r.patch allows the user to build a new raster map the
34 size and resolution of the current region by assigning known data val‐
35 ues from input raster maps to the cells in this region. This is done
36 by filling in "no data" cells, those that do not yet contain data, con‐
37 tain NULL data, or, optionally contain 0 data, with the data from the
38 first input map. Once this is done the remaining holes are filled in
39 by the next input map, and so on. This program is useful for making a
40 composite raster map layer from two or more adjacent map layers, for
41 filling in "holes" in a raster map layer's data (e.g., in digital ele‐
42 vation data), or for updating an older map layer with more recent data.
43 The current geographic region definition and mask settings are
44 respected.
45 The first name listed in the string input=name,name,name, ... is the
47 name of the first map whose data values will be used to fill in "no
48 data" cells in the current region. The second through 200 (max) input
49 name maps will be used, in order, to supply data values for for the
50 remaining "no data" cells.
51
53 Below, the raster map layer on the far left is patched with the middle
54 (patching) raster map layer, to produce the composite raster map layer
55 on the right.
56 1 1 1 0 2 2 0 0 0 0 1 1 0 0 0 0 1 1 1 1 2 2 0 0
57 1 1 0 2 2 2 0 0 0 0 1 1 0 0 0 0 1 1 1 2 2 2 0 0
58 3 3 3 3 2 2 0 0 0 0 0 0 0 0 0 0 3 3 3 3 2 2 0 0
59 3 3 3 3 0 0 0 0 4 4 4 4 4 4 4 4 3 3 3 3 4 4 4 4
60 3 3 3 0 0 0 0 0 4 4 4 4 4 4 4 4 3 3 3 4 4 4 4 4
61 0 0 0 0 0 0 0 0 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4
62 Switching the patched and the patching raster map layers produces the
63 following results:
64 0 0 1 1 0 0 0 0 1 1 1 0 2 2 0 0 1 1 1 1 2 2 0 0
65 0 0 1 1 0 0 0 0 1 1 0 2 2 2 0 0 1 1 1 1 2 2 0 0
66 0 0 0 0 0 0 0 0 3 3 3 3 2 2 0 0 3 3 3 3 2 2 0 0
67 4 4 4 4 4 4 4 4 3 3 3 3 0 0 0 0 4 4 4 4 4 4 4 4
68 4 4 4 4 4 4 4 4 3 3 3 0 0 0 0 0 4 4 4 4 4 4 4 4
69 4 4 4 4 4 4 4 4 0 0 0 0 0 0 0 0 4 4 4 4 4 4 4 4
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73 Frequently, this program is used to patch together adjacent map layers
74 which have been digitized separately. The program v.mkgrid can be used
75 to make adjacent maps align neatly.
76 The user should check the current geographic region settings before
78 running r.patch, to ensure that the region boundaries encompass all of
79 the data desired to be included in the composite map and to ensure that
80 the region resolution is the resolution of the desired data. To set the
81 geographic region settings to one or several raster maps, the g.region
82 program can be used:
83 g.region rast=map1[,map2[,...]]
84 Use of r.patch is generally followed by use of the GRASS programs
87 g.remove and g.rename; g.remove is used to remove the original (un-
88 patched) raster map layers, while g.rename is used to then assign to
89 the newly-created composite (patched) raster map layer the name of the
90 original raster map layer.
91 r.patch creates support files for the patched, composite output map.
93
95 Create a list of maps matching a pattern, extend the region to include
96 them all, and patch them together to create a mosaic. Overlapping maps
97 will be used in the order listed.
98 MAPS=`g.mlist type=rast sep=, pat="map_*"`
99 g.region rast=$MAPS
100 r.patch in=$MAPS out=mosaic
101
104 g.region, g.remove, g.rename, r.mapcalc, r.support, v.mkgrid
105
107 Michael Shapiro, U.S. Army Construction Engineering Research Laboratory
108 -z flag by Huidae Cho
109 Last changed: $Date: 2006/05/15 02:02:12 $
111 Full index
113GRASS 6.2.2 r.patch(1)