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


       raster, surface, fractal

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

           Allow output files to overwrite existing files

           Print usage summary

           Verbose module output

           Quiet module output

           Force launching GUI dialog

       output=name [required]
           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).

       This module generates naturally looking synthetical elevation models (DEM).


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


       Generate surface using fractals in selected region,  set  color  table  and  display  with
       g.region -p raster=elevation output=fractals
       r.colors map=fractals color=byr
       r.relief input=fractals output=fractals_shade
       d.mon wx0
       d.shade shade=fractals_shade color=fractals b=50
       Artificial surface created with fractals
       Compare results when using different fractal dimensions:
       # 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
       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.



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

       Last changed: $Date: 2015-07-20 10:45:41 +0200 (Mon, 20 Jul 2015) $


       Available at: source code (history)

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