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.
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
Generates tiles in latitude longitude projection that cover the named region
"ne-rio". The tiles will have 2 cells of overlap. The output format
will be strings like the bbox requests for WMS servers:
r.tileset sourceproj=+init=epsg:4326 overlap=2 -w region=ne-rio
Generates tiles in the projection of the location "IrishGrid". Each
tile will be less than 300x400 cells in size, with 3 cells of overlap in the
top and right sides of each tile. The output is in a format where each line is
in shell script style. The substitution
`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
Updated for GRASS 7 by Martin Landa, CTU in Prague, Czech Republic
Last changed: $Date: 2011-11-08 12:29:50 +0100 (Tue, 08 Nov 2011) $
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© 2003-2011 GRASS Development Team