[GRASS-SVN] r54066 - grass/branches/releasebranch_6_4/raster/r.surf.fractal
svn_grass at osgeo.org
svn_grass at osgeo.org
Mon Nov 26 16:18:54 PST 2012
Author: neteler
Date: 2012-11-26 16:18:53 -0800 (Mon, 26 Nov 2012)
New Revision: 54066
Added:
grass/branches/releasebranch_6_4/raster/r.surf.fractal/r_surf_fractal.jpg
Modified:
grass/branches/releasebranch_6_4/raster/r.surf.fractal/
grass/branches/releasebranch_6_4/raster/r.surf.fractal/description.html
Log:
+ example, +image
Property changes on: grass/branches/releasebranch_6_4/raster/r.surf.fractal
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Modified: svn:ignore
- *.tmp.html
*OBJ*
+ OBJ.*
*.tmp.html
Modified: grass/branches/releasebranch_6_4/raster/r.surf.fractal/description.html
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--- grass/branches/releasebranch_6_4/raster/r.surf.fractal/description.html 2012-11-26 22:25:02 UTC (rev 54065)
+++ grass/branches/releasebranch_6_4/raster/r.surf.fractal/description.html 2012-11-27 00:18:53 UTC (rev 54066)
@@ -1,20 +1,57 @@
<h2>DESCRIPTION</h2>
<b>r.surf.fractal</b> creates a fractal surface of a given fractal
-dimension. Uses spectral synthesis method. Can create intermediate layers
-showing the build up of different spectral coefficients (see Saupe,
-pp.106-107 for an example of this).
+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).
<p>
Use this module to generate naturally looking synthetical elevation models
(DEM).
-
<h2>NOTE</h2>
This module requires the <a href="http://www.fftw.org">FFTW library</a>
for computing Discrete Fourier Transforms.
+<h2>EXAMPLE</h2>
+<div class="code"><pre>
+# D=2.0005
+g.region -dp
+r.surf.fractal out=dem_d2_0005 dim=2.0005
+r.info -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
+r.surf.fractal out=dem_d2_90 dim=2.90
+r.info -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.split.frame
+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
+</pre></div>
+
+<center>
+<img src="r_surf_fractal.jpg" alt="Artificial DEMs created with fractals"><br>
+Artificial DEMs created with fractals:<br>
+top: fractal dimension d=2.0005 (left: elevation map, right: aspect map)<br>
+top: fractal dimension d=2.90 (left: elevation map, right: aspect map)
+</center>
+
+
<h2>REFERENCE</h2>
Saupe, D. (1988) Algorithms for random fractals, in Barnsley M.,
Devaney R., Mandelbrot B., Peitgen, H-O., Saupe D., and Voss R.
Added: grass/branches/releasebranch_6_4/raster/r.surf.fractal/r_surf_fractal.jpg
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Property changes on: grass/branches/releasebranch_6_4/raster/r.surf.fractal/r_surf_fractal.jpg
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Added: svn:mime-type
+ image/jpeg
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