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

6       r.in.mat  - Imports a binary MAT-File(v4) to a GRASS raster.
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KEYWORDS

9       raster, import
10

SYNOPSIS

12       r.in.mat
13       r.in.mat --help
14       r.in.mat  input=name   [output=name]   [--overwrite]  [--help]  [--ver‐
15       bose]  [--quiet]  [--ui]
16
17   Flags:
18       --overwrite
19           Allow output files to overwrite existing files
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21       --help
22           Print usage summary
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24       --verbose
25           Verbose module output
26
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 MAT-File(v4)
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37       output=name
38           Name for output raster map (override)
39

DESCRIPTION

41       r.in.mat will import a GRASS raster map from a Version 4 MAT-File which
42       was  created  with  Matlab or Octave.  Attributes such as map title and
43       bounds will also be imported if they exist.
44       Specifically, the following array variables will be read:
45
46           ·
47                map_data
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49           ·
50                map_name
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52           ·
53                map_title
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55           ·
56                map_northern_edge
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58           ·
59                map_southern_edge
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61           ·
62                map_eastern_edge
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64           ·
65                map_western_edge
66       Any other variables in the MAT-file will be simply skipped over.
67       The ’map_name’ variable is optional, if it exists, and  is  valid,  the
68       new  map will be thus named. If it doesn’t exist or a name is specified
69       with the output= option, the raster map’s name will be set to "MatFile"
70       or  the  name  specified  respectively.  (maximum 64 characters; normal
71       GRASS naming rules apply)
72       The ’map_title’ variable is optional, the map’s  title  is  set  if  it
73       exists.
74       The  ’map_northern_edge’  and  like  variables are mandatory unless the
75       user is importing to a "XY" non-georeferenced  location  (e.g.  imagery
76       data). Latitude and longitude values should be in decimal form.
77

NOTES

79       r.in.mat  imports a Version 4 MAT-File. These files can be successfully
80       created with more modern versions of Matlab and Octave (see  "EXAMPLES"
81       below).
82       Everything  should  be  Endian  safe, so the file to be imported can be
83       simply copied between different  system  architectures  without  binary
84       translation (caveat: see "TODO" below).
85       As there is no IEEE value for NaN in integer arrays, GRASS’s null value
86       may be used to represent it within these maps. Usually Matlab will save
87       any integer based matrix with NaN values as a double-precision floating
88       point array, so this usually isn’t an issue. To save  space,  once  the
89       map is loaded into GRASS you can convert it back to an integer map with
90       the following command:
91       r.mapcalc "int_map = int(MATFile_map)"
92       NaN values in either floating point or double-precision floating  point
93       matrices should translate into null values as expected.
94       r.in.mat  must  load  the  entire map array into memory before writing,
95       therefore it might have problems with huge arrays.  (a 3000x4000  DCELL
96       map uses about 100mb RAM)
97       GRASS  defines  its map bounds at the outer-edge of the bounding cells,
98       not at the coordinates of their centroids. Thus, the  following  Matlab
99       commands may be used to determine and check the map’s resolution infor‐
100       mation will be correct:
101           [rows cols] = size(map_data)
102           x_range = map_eastern_edge - map_western_edge
103           y_range = map_northern_edge - map_southern_edge
104           ns_res = y_range/rows
105           ew_res = x_range/cols
106       Remember Matlab arrays are referenced as (row,column), i.e. (y,x).
107       In addition, r.in.mat and r.out.mat make for a  nice  binary  container
108       format  for  transferring  georeferenced maps around, even if you don’t
109       use Matlab or Octave.
110

EXAMPLES

112       In Matlab, save with:
113       save filename.mat map_* -v4
114       In Octave, save with:
115       save -mat4-binary filename.mat map_*
116

TODO

118       Robust support for  mixed-Endian  importation.   (This  is  a  work  in
119       progress, please help by reporting any failures to the GRASS bug track‐
120       ing system;
121       Add support for importing map history, category information, color map,
122       etc.  if they exist.
123       Option to import a version 5 MAT-File, with map and support information
124       stored in a single structured array.
125

KNOWN ISSUES

127       If you encounter any problems, please  contact  the  GRASS  Development
128       Team.
129

SEE ALSO

131        r.out.mat, r.in.ascii, r.in.bin, r.mapcalc, r.null.
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133        The Octave project
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AUTHOR

136       Hamish Bowman
137        Department of Marine Science
138       University of Otago
139       New Zealand
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SOURCE CODE

142       Available at: r.in.mat source code (history)
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144       Main  index  | Raster index | Topics index | Keywords index | Graphical
145       index | Full index
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147       © 2003-2020 GRASS Development Team, GRASS GIS 7.8.5 Reference Manual
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151GRASS 7.8.5                                                        r.in.mat(1)
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