1r.tileset(1) Grass User's Manual r.tileset(1)
2
6 r.tileset - Produces tilings of the source projection for use in the
7 destination region and projection.
8
10 raster, tiling
11
13 r.tileset
14 r.tileset help
15 r.tileset [-gw] [region=string] sourceproj=string
16 [sourcescale=string] [destproj=string] [destscale=string] [max‐
17 cols=integer] [maxrows=integer] [overlap=integer] [fs=string]
18 [v=integer]
19 Flags:
21 -g Produces shell script output
22 -w Produces web map server query string output
24 Parameters:
26 region=string
27 Name of region to use instead of current region for bounds and res‐
28 olution
29 sourceproj=string
31 Source projection
32 sourcescale=string
34 Conversion factor from units to meters in source projection
35 Default: 1
36 destproj=string
38 Destination projection, defaults to this location's projection
39 destscale=string
41 Conversion factor from units to meters in source projection
42 maxcols=integer
44 Maximum number of columns for a tile in the source projection
45 Default: 1024
46 maxrows=integer
48 Maximum number of rows for a tile in the source projection Default:
49 1024
50 overlap=integer
52 Number of cells tiles should overlap in each direction Default: 0
53 fs=string
55 Output field seperator Default: |
56 v=integer
58 Verbosity level Default: 0
59
61 r.tileset generates sets of tiles in another projection that cover a
62 region in this projection with adequate resolution. By default the cur‐
63 rent region and its resolution are used, the bounds and resolution of
64 another region can be used via the region option.
65
67 r.tileset does not make "optimal" tilings (as few tiles of the largest
68 size less than the maximums). This means that from latitude longitude
69 projection to an appropriate projection for a region, in the degenerate
70 case, it may create tiles demanding up to twice the necessary informa‐
71 tion. Furthermore, generating a tiling near a divergant point of a
72 source projection, such as the poles of a cylindrical source projec‐
73 tions, results in divergence of the tile set.
74 Not generating "optimal" tilings may have another consequence; the
76 aspect ratio of cells in the destination region will not necessarily
77 carry over to the source region and generated tiles may have cells of
78 strange aspect ratios. This might be a problem for some map request
79 services presenting data in an inappropriate projection or with strict
80 constraints on cell aspect ratio.
81
83 Each tile is listed on a seperate line in the output. The lines are
84 formatted as follows:
85 5|125|45|175|80|100
88 This is the default output format. It is the tile's minimum x
89 coordinate, minimum y coordinate, maximum x coordinate, maximum
90 y coordinate, width in cells, and height in cells seperated by
91 the "|" character. The fields can be seperated by a different
92 character by changing the fs option.
93 w=5;s=125;e=45;n=175;cols=80;rows=100;
96 This is output in a format convinent for setting variables in a
97 shell script.
98 bbox=5,125,45,175&width=80&height=100
101 This is output in a format convinent for requesting data from
102 some http services.
103
105 r.tileset sourceproj=+init=epsg:4326 maxrows=1024 maxcols=2048
107 Generates tiles in latitude longitude that cover the current
108 region, each tile will be less than 1024 cells high and 2048
109 cells across. The bounds and sizes of tiles in the output are
110 seperated by |
111 r.tileset sourceproj=+init=epsg:4326 overlap=2 -w region=ne-rio
114 Generates tiles in latitude longitude projection that cover the
115 named region "ne-rio". The tiles will have 2 cells of overlap.
116 The output format will be strings like the bbox requests for WMS
117 servers.
118 r.tileset sourceproj=`g.proj -j location=IrishGrid` maxrows=400
121 maxcols=300 overlap=3 -g
122 Generates tiles in the projection of the location "IrishGrid".
123 Each tile will be less than 300x400 cells in size, with 3 cells
124 of overlap in the top and right sides of each tile. The output
125 is in a format where each line is in shell script style. The
126 substitution `g.proj -j location=IrishGrid` will only work in a
127 unix style shell.
128
130 r.tileset requires the following programs to work:
131 cs2cs The coordinate system transformation program from Proj4.
133 bc A calculator program
135 sed, grep
137 Unix string processing and search programs
138
140 r.tileset does not know about meridians that "wrap-
141 around" in projections.
142
144 Cedric Shock
145 Last changed: $Date: 2006/05/02 01:49:52 $
147 Full index
149GRASS 6.2.2 r.tileset(1)