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NAME  - Creates a fractal surface of a given fractal dimension.


       raster, DEM, fractal

SYNOPSIS help    output=name     [dimension=float]     [number=integer]     [--overwrite]
       [--verbose]  [--quiet]

           Allow output files to overwrite existing files

           Verbose module output

           Quiet module output

           Name for output raster map

           Fractal dimension of surface (2 < D < 3)
           Default: 2.05

           Number of intermediate images to produce
           Default: 0

DESCRIPTION creates a fractal surface  of  a  given  fractal  dimension.  It  uses  the
       spectral  synthesis method. The module can create intermediate layers showing the build up
       of different spectral coefficients (see Saupe, pp.106-107 for an example of this).

       Use this module to generate naturally looking synthetical elevation models (DEM).


       This module requires the FFTW library for computing Discrete Fourier Transforms.


       # D=2.0005
       g.region -dp out=dem_d2_0005 dim=2.0005 -r dem_d2_0005
       r.mapcalc "dem_d2_0005_final = 1.0 * dem_d2_0005 + abs(min(dem_d2_0005))"
       r.colors dem_d2_0005_final color=terrain
       r.slope.aspect dem_d2_0005_final aspect=dem_d2_0005_final_as
       # D=2.90 out=dem_d2_90 dim=2.90 -r dem_d2_90
       r.mapcalc "dem_d2_90_final = 1.0 * dem_d2_90 + abs(min(dem_d2_90))"
       r.colors dem_d2_90_final color=terrain
       r.slope.aspect dem_d2_90_final aspect=dem_d2_90_final_as
       d.mon x0
       d.erase -f
       d.frame -s uno
       d.rast dem_d2_0005_final
       d.frame -s dos
       d.rast dem_d2_0005_final_as
       d.frame -s tres
       d.rast dem_d2_90_final
       d.frame -s cuatro
       d.rast dem_d2_90_final_as
        Artificial DEMs created with fractals:
       top: fractal dimension d=2.0005 (left: elevation map, right: aspect map)
       top: fractal dimension d=2.90 (left: elevation map, right: aspect map)


       Saupe, D. (1988) Algorithms for random fractals, in Barnsley M.,  Devaney  R.,  Mandelbrot
       B.,  Peitgen,  H-O.,  Saupe  D., and Voss R.  (1988) The Science of Fractal Images, Ch. 2,
       pp.71-136. London: Springer-Verlag.

SEE ALSO,,,,,,


       Jo Wood, Midlands Regional Research Laboratory (ASSIST), University of Leicester

       Last changed: $Date: 2012-11-26 16:18:53 -0800 (Mon, 26 Nov 2012) $

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