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]   [separator=character]   [--help]  [--verbose]  [--quiet]  [--ui]

   Flags:
       -g
           Produces shell script output

       -w
           Produces web map server query string output

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       region=string
           Name of region to use instead of current region for bounds and resolution

       sourceproj=string [required]
           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

       separator=character
           Field separator
           Output field separator
           Default: pipe

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
       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

KNOWN ISSUES

           •   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: 2015-05-11 02:16:13 +0200 (Mon, 11 May 2015) $

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