1r.out.mat(1)                GRASS GIS User's Manual               r.out.mat(1)
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NAME

6       r.out.mat  - Exports a GRASS raster to a binary MAT-File.
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KEYWORDS

9       raster, export, output
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SYNOPSIS

12       r.out.mat
13       r.out.mat --help
14       r.out.mat  input=name output=name  [--overwrite]  [--help]  [--verbose]
15       [--quiet]  [--ui]
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17   Flags:
18       --overwrite
19           Allow output files to overwrite existing files
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21       --help
22           Print usage summary
23
24       --verbose
25           Verbose module output
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27       --quiet
28           Quiet module output
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30       --ui
31           Force launching GUI dialog
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33   Parameters:
34       input=name [required]
35           Name of input raster map
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37       output=name [required]
38           Name for output binary MAT file
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DESCRIPTION

41       r.out.mat will export a GRASS raster map to a  MAT-File  which  can  be
42       loaded  into  Matlab  or  Octave  for  plotting  or  further  analysis.
43       Attributes such as map title and bounds  will  also  be  exported  into
44       additional array variables.
45       Specifically, the following array variables are created:
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47           ·
48                map_data
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50           ·
51                map_name
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53           ·
54                map_title (if it exists)
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56           ·
57                map_northern_edge
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59           ·
60                map_southern_edge
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62           ·
63                map_eastern_edge
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65           ·
66                map_western_edge
67       In  addition,  r.out.mat  makes  for a nice binary container format for
68       transferring georeferenced maps around, even if you don’t use Matlab or
69       Octave.
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NOTES

72       r.out.mat exports a Version 4 MAT-File. These files should successfully
73       load into more modern versions of Matlab and Octave without  any  prob‐
74       lems.
75       Everything  should  be Endian safe, so the resultant file can be simply
76       copied between different system architectures without  binary  transla‐
77       tion.
78       As  there is no IEEE value for NaN for integer maps, GRASS’s null value
79       is used to represent it within these maps. You’ll have to do  something
80       like this to clean them once the map is loaded into Matlab:
81           map_data(find(map_data < -1e9)) = NaN;
82       Null  values  in maps containing either floating point or double-preci‐
83       sion floating point data should translate into NaN values as expected.
84       r.out.mat must load the entire map into memory before  writing,  there‐
85       fore  it  might  have  problems with huge maps.  (a 3000x4000 DCELL map
86       uses about 100mb RAM)
87       GRASS defines its map bounds at the outer-edge of the  bounding  cells,
88       not  at  the coordinates of their centroids. Thus, the following Matlab
89       commands may be used to determine the map’s resolution information:
90           [rows cols] = size(map_data)
91           x_range = map_eastern_edge - map_western_edge
92           y_range = map_northern_edge - map_southern_edge
93           ns_res = y_range/rows
94           ew_res = x_range/cols
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EXAMPLE

97       In Matlab, plot with either:
98       imagesc(map_data), axis equal, axis tight, colorbar
99       or
100       contourf(map_data, 24), axis ij, axis equal, axis tight, colorbar
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TODO

103       Add support for exporting map history, category information, color map,
104       etc.
105       Option to export as a version 5 MAT-File, with map and support informa‐
106       tion stored in a single structured array.
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SEE ALSO

109        r.in.mat
110       r.out.ascii, r.out.bin
111       r.null
112       The Octave project
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AUTHOR

115       Hamish Bowman
116        Department of Marine Science
117       University of Otago
118       New Zealand
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SOURCE CODE

121       Available at: r.out.mat source code (history)
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123       Main index | Raster index | Topics index | Keywords index  |  Graphical
124       index | Full index
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126       © 2003-2020 GRASS Development Team, GRASS GIS 7.8.5 Reference Manual
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130GRASS 7.8.5                                                       r.out.mat(1)
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