NAME

       libgrass_rli - r.li landscape index support library

DESCRIPTION

       r.li.daemon  provides support for landscape index calculations on raster maps. It hides the management of
       areas, defined using r.li.setup command. It is not used like a standalone program, but its functions  are
       a library used by all r.li.[index] commands.
       This description is a tutorial for new index definition.
       The  developer has only to focus on a unique area, like in mathematical definitions, and has to write a C
       implementation of it.
       The areas are defined using a struct called area_des and it members are  explained  in  the  source  code
       (doxygen) documentation.

       To write a new index only two steps are needed:

       1      Define a function and insert its declaration on file index.h in r.li.daemon folder, which contains
              all index declarations. This function must be of this kind:
                      int index(int fd, char ** par, area_des ad, double * result)

              where:

                     fd is the raster map descriptor

                     par is a matrix for special parameter (like argv in main)

                     ad is the area descriptor

                     result is where to put the index calculation result
       This function has to return 1 on success and 0 otherwise.

       6      Create a main for command line arguments parsing, and call the function
                      int  calculateIndex(char * file, int f(int, char** area_des, double *), char **parameters,
              char *raster, char *output);

              from the r.li library, for starting raster analysis.
              It follows the meaning of parameters:

                     file name of configuration file created using r.li.setup

                     f pointer to index function defined above

                     parameters pointer to index special parameters

                     raster name of raster to use

                     output output file name

       Compile it using a changed Makefile based on the file for r.li.patchdensity.

NOTES

       Using GRASS library function to access raster  rows  can  slow  down  moving  windows  execution.  It  is
       recommended to use
       RLI_get_cell_row(int, int, area_des)
       RLI_get_fcell_row(int, int, area_des)
       RLI_get_dcell_row(int, int, area_des)

       to  use  an  ad  hoc  build  memory management developed to speed up the system.  The documentation is in
       doxygen files.

SEE ALSO

       old r.le manual
       r.li package overview
       r.li.patchdensity, r.li.setup

AUTHORS

       Claudio Porta and Lucio Davide Spano, students of Computer Science University of Pisa (Italy).
       Commission from Faunalia Pontedera (PI)
       Rebuild of r.le.setup from William L. Baker This program is free software under the GPL (>=v2)  Read  the
       COPYING file that comes with GRASS for details.

       Last changed: $Date: 2013-06-16 05:08:46 +0200 (Sun, 16 Jun 2013) $

       Full index

GRASS 6.4.3                                                                                  r.li.daemon(1grass)