1r.li.daemon(1)                Grass User's Manual               r.li.daemon(1)
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DESCRIPTION

6       r.li.daemon  provides  a  support  for  landscape  index calculation on
7       raster maps. It hides the managment of areas, defined using  r.li.setup
8       command.  It  do not have to be used like a standalone program, but its
9       functions are a library used by all r.li.[index] commands.
10       This description is a tutorial for new index definition.
11       The developer has only to focus on a unique area, like in  mathematical
12       definitions, and has to write a C implementation of it.
13       The areas are defined using a struct called area_des and it members are
14       explained in the source code (doxygen) documentation.
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16       To write a new index only two steps are needed:
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18       1      Define a function and insert its declaration on file index.h  in
19              r.li.daemon  folder, which contains all index declarations. This
20              function must be of this kind:
21                      int index(int fd, char ** par,  area_des  ad,  double  *
22              result)
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24              where:
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26                     fd is the raster map descriptor
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28                     par is a matrix for special parameter (like argv in main)
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30                     ad is the area descriptor
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32                     result is where to put the index calculation result
33       This function has to return 1 on success and 0 otherwise.
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35       6      Create  a  main for command line arguments parsing, and call the
36              function
37                      int  calculateIndex(char  *  file,  int  f(int,   char**
38              area_des, double *), char **parameters, char *raster, char *out‐
39              put);
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41              from the r.li library, for starting raster analysis.
42              It follows the meaning of parameters:
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44                     file name of configuration file created using r.li.setup
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46                     f pointer to index function defined above
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48                     parameters pointer to index special parameters
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50                     raster name of raster to use
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52                     output output file name
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54       Compile it using a changed Makefile based on the file  for  r.li.patch‐
55       density.
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NOTES

58       Using GRASS library function to access raster rows can slow down moving
59       windows execution. It is recommended to use
60       RLI_get_cell_row(int, int, area_des)
61       RLI_get_fcell_row(int, int, area_des)
62       RLI_get_dcell_row(int, int, area_des)
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64       to use an ad hoc build memory managment developed to speed up the  sys‐
65       tem.  The documentation is in doxygen files.
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SEE ALSO

68       old r.le manual
69       r.li package overview
70       r.li.patchdensity, r.li.setup
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AUTHORS

73       Claudio Porta and Lucio Davide Spano, students of Computer Science Uni‐
74       versity of Pisa (Italy).
75       Commission from Faunalia Pontedera (PI)
76       Rebuild of r.le.setup from William L. Baker This program is free  soft‐
77       ware  under  the GPL (>=v2) Read the COPYING file that comes with GRASS
78       for details.
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BUGS

81       Pleas send bugs reports to spano@cli.di.unipi.it, porta@cli.di.unipi.it
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83       Last changed: $Date: 2007-03-11 18:50:13 +0100 (Sun, 11 Mar 2007) $
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85       Full index
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89GRASS 6.3.0                                                     r.li.daemon(1)
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