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NAME

r.surf.volcano

DESCRIPTION

r.surf.volcano creates an artificial surface resembling a seamount or cone volcano. The user can alter the size and shape of the mountain and optionally roughen its surface.

NOTES

The friction of distance controls the shape of the mountain when using the default polynomial method. Higher values generate steeper slopes.

The pseudo-kurtosis factor is used with all other methods to control the slope steepness. For the Gaussian method setting the value nearer to zero creates a flatter surface, while higher values generate steeper slopes. For Lorentzian, logarithmic, and exponential methods the opposite is true.

The surface roughness factor controls the fixed standard deviation distance (sigma) used in the Gaussian random number generator. It is only used when the -r roughen surface flag is turned on. A value closer to zero makes a smoother surface, a higher value makes a rougher surface.

It is possible to set a negative value for the peak in order to create a pit.

EXAMPLES

r.surf.volcano -r output=seamount

# view in the display monitor
r.colors seamount color=sepia -e
d.rast seamount

# view in 3D
r.colors seamount color=srtm
nviz seamount

# export to Matlab
r.out.mat in=seamount out=seamount.mat

# integrate into existing DEM
r.mapcalc "seamount_dem=if(seamount > dem, seamount, dem)"
r.colors seamount_dem color=srtm
Create a roughened volcano with a crater: 
r.surf.volcano -r output=volcano crater=250 --verbose
r.shaded.relief volcano
Create a fancy 3D scene: 
r.surf.volcano -r output=base_volcano peak=600 crater=120
r.surf.fractal output=base_fractal
r.mapcalc "artificial_land = base_volcano + base_fractal"
r.colors artificial_land color=srtm
nviz artificial_land

SEE ALSO

r.surf.fractal
r.surf.gauss
r.surf.random

AUTHOR

Hamish Bowman
Dept. Marine Science
University of Otago
Dunedin, New Zealand

Last changed: $Date$

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