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NAME  - Imports a binary MAT-File(v4) to a GRASS raster.


       raster, import

SYNOPSIS help [-v] input=string  [output=string]   [--overwrite]  [--verbose]  [--quiet]

           Verbose mode

           Allow output files to overwrite existing files

           Verbose module output

           Quiet module output

           Name of an existing MAT-File(v4)

           Name for the output raster map (override)

DESCRIPTION  will  import a GRASS raster map from a Version 4 MAT-File which was created with
       Matlab or Octave.  Attributes such as map title and bounds will also be imported  if  they
       Specifically, the following array variables will be read:
       Any other variables in the MAT-file will be simply skipped over.
       The  'map_name' variable is optional, if it exists, and is valid, the new map will be thus
       named. If it doesn't exist or a name is specified with  the  output=  option,  the  raster
       map's  name  will  be  set  to  "MatFile" or the name specified respectively.  (maximum 64
       characters; normal GRASS naming rules apply)
       The 'map_title' variable is optional, the map's title is set if it exists.
       The 'map_northern_edge' and like variables are mandatory unless the user is importing to a
       "XY"  non-georeferenced location (e.g. imagery data). Latitude and longitude values should
       be in decimal form.

NOTES imports a Version 4 MAT-File. These files can be successfully created  with  more
       modern versions of Matlab and Octave (see "EXAMPLES" below).
       Everything  should be Endian safe, so the file to be imported can be simply copied between
       different system architectures without binary translation (caveat: see "TODO" below).
       As there is no IEEE value for NaN in integer arrays, GRASS's null value  may  be  used  to
       represent it within these maps. Usually Matlab will save any integer based matrix with NaN
       values as a double-precision floating point array, so this usually isn't an issue. To save
       space,  once  the  map is loaded into GRASS you can convert it back to an integer map with
       the following command:
       r.mapcalc int_map="int(MATFile_map)"
        NaN values in either floating point or double-precision floating  point  matrices  should
       translate into null values as expected.  must  load  the  entire map array into memory before writing, therefore it might
       have problems with huge arrays.  (a 3000x4000 DCELL map uses about 100mb RAM)
       GRASS defines its map bounds  at  the  outer-edge  of  the  bounding  cells,  not  at  the
       coordinates  of  their  centroids.  Thus,  the  following  Matlab  commands may be used to
       determine and check the map's resolution information will be correct:
           [rows cols] = size(map_data)
           x_range = map_eastern_edge - map_western_edge
           y_range = map_northern_edge - map_southern_edge
           ns_res = y_range/rows
           ew_res = x_range/cols

       Remember Matlab arrays are referenced as (row,column), i.e. (y,x).
       In addition,  and  r.out.mat  make  for  a  nice  binary  container  format  for
       transferring georeferenced maps around, even if you don't use Matlab or Octave.


       In Matlab, save with:
       save filename.mat map_* -v4
        In Octave, save with:
       save -mat4-binary filename.mat map_*


       Robust  support for mixed-Endian importation.  (This is a work in progress, please help by
       reporting any failures to the GRASS bug tracking system; you will need to  login  with  an
       OSGeo Userid)
       Add  support  for  importing  map  history, category information, color map, etc.  if they
       Option to import a version 5 MAT-File, with map and support information stored in a single
       structured array.


       If you encounter any problems, please contact the GRASS Development Team.


        r.out.mat,,, r.mapcalc, r.null.

       The Octave project


       Hamish Bowman

       Department of Marine Science
       University of Otago
       New Zealand

       Last changed: $Date: 2011-11-08 03:29:50 -0800 (Tue, 08 Nov 2011) $

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