Geografic-Information-System/raster/r.random.cells

/****************************************************************************
*
* MODULE: r.random.cells
* AUTHOR(S): Charles Ehlschlaeger; National Center for Geographic
* Information and Analysis, University of California, Santa
* Barbara (original contributor)
* Markus Neteler
* Roberto Flor ,
* Brad Douglas ,
* Glynn Clements Markus Neteler (original contributor)
* Bernhard Reiter
* PURPOSE: generates a random sets of cells that are at least
* some distance apart
* COPYRIGHT: (C) 2000-2004 by the GRASS Development Team
*
* This program is free software under the GNU General Public
* License (>=v2). Read the file COPYING that comes with GRASS
* for details.
*
*****************************************************************************/

r.random.cells generates a random sets of cells that are at least
some distance apart. The cells are numbered from 1 to the numbers of
cells generated. Random cells will not be generated in areas masked off.

OPTIONS
-q
This flag prevents the program from sending a verbose description to standard
output of what the program is doing.

-output

Output map: Random cells. Each random cell has a unique non-zero cell
value ranging from 1 to the number of cells generated. The heuristic for
this algorithm is to randomly pick cells until there are no cells outside
of the chosen cell's buffer of radius \fIdistance\fR.

-distance
Input value(s) [default 0.0]: distance determines the minimum distance
the centers of the random cells will be apart.

-seed
Input value [default: random]: Specifies the random seed that
r.random.cells will use to generate the cells. If the random seed
is not given, then it will get a seed from the process ID number.

NOTES
The original purpose for this program was to generate independent random
samples of cells in a study area. The distancevalue is the amount
of spatial autocorrelation for the map being studied.