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NAME
r.tileset - Produces tilings of the source projection for use in the destination region and projection.
KEYWORDS
raster, tiling
SYNOPSIS
r.tileset
r.tileset help
r.tileset [-gw] [region=string] sourceproj=string [sourcescale=string] [destproj=string] [destscale=string] [maxcols=integer] [maxrows=integer] [overlap=integer] [fs=string] [v=integer] [--verbose] [--quiet]
Flags:
- -g
- Produces shell script output
- -w
- Produces web map server query string output
- --verbose
- Verbose module output
- --quiet
- Quiet module output
Parameters:
- region=string
- Name of region to use instead of current region for bounds and resolution
- sourceproj=string
- Source projection
- sourcescale=string
- Conversion factor from units to meters in source projection
- Default: 1
- destproj=string
- Destination projection, defaults to this location's projection
- destscale=string
- Conversion factor from units to meters in source projection
- maxcols=integer
- Maximum number of columns for a tile in the source projection
- Default: 1024
- maxrows=integer
- Maximum number of rows for a tile in the source projection
- Default: 1024
- overlap=integer
- Number of cells tiles should overlap in each direction
- Default: 0
- fs=string
- Output field separator
- Default: |
- v=integer
- Verbosity level
- Default: 0
DESCRIPTION
r.tileset generates sets of tiles in another projection that
cover a region in this projection with adequate resolution. By default
the current region and its resolution are used, the bounds and
resolution of another region can be used via the region option.
NOTES
r.tileset does not make "optimal" tilings (as few tiles of
the largest size less than the maximums). This means that from
latitude longitude projection to an appropriate projection for a
region, in the degenerate case, it may create tiles demanding up to
twice the necessary information. Furthermore, generating a tiling near
a divergant point of a source projection, such as the poles of a
cylindrical source projections, results in divergence of the tile set.
Not generating "optimal" tilings may have another consequence; the
aspect ratio of cells in the destination region will not necessarily
carry over to the source region and generated tiles may have cells of
strange aspect ratios. This might be a problem for some map request
services presenting data in an inappropriate projection or with strict
constraints on cell aspect ratio.
OUTPUT FORMAT
Each tile is listed on a separate line in the output. The lines are
formatted as follows:
-
5|125|45|175|80|100
- This is the default output format. It is the tile's minimum x
coordinate, minimum y coordinate, maximum x coordinate, maximum y
coordinate, width in cells, and height in cells separated by the "|"
character. The fields can be separated by a different character by
changing the fs option.
-
w=5;s=125;e=45;n=175;cols=80;rows=100;
- This is output in a format convinent for setting variables in a shell
script.
-
bbox=5,125,45,175&width=80&height=100
- This is output in a format convinent for requesting data from some
http services.
EXAMPLES
Generates tiles in latitude longitude that cover the current
region, each tile will be less than 1024 cells high and 2048 cells
across. The bounds and sizes of tiles in the output are separated by | (pipe):
r.tileset sourceproj=+init=epsg:4326 maxrows=1024 maxcols=2048
r.tileset sourceproj=+init=epsg:4326 overlap=2 -w region=ne-rio
`g.proj -j location=IrishGrid` will only
work in a unix style shell:
r.tileset sourceproj="`g.proj -j location=IrishGrid`" maxrows=400 maxcols=300 overlap=3 -g
BUGS
- r.tileset does not know about meridians that
"wrap-around" in projections.
AUTHORS
Cedric Shock
Update by Martin Landa, CTU in Prague, Czech Republic
Last changed: $Date: 2012-12-14 05:07:05 -0800 (Fri, 14 Dec 2012) $
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