.TH r.param.scale 1 "" "" "" ""
 
.SH 
NAME
\*Lr.param.scale\*O - GRASS module that extracts terrain parameters from
a DEM. Uses a multi-scalar approach by taking fitting quadratic parameters
to any size window (via least squares).
.SH 
Usage:
\*Lr.param.scale\*O [-c] \*Lin=\*Oname \*Lout=\*Oname [\*Ls_tol=\*Ovalue]
[\*Lc_tol=\*Ovalue] [\*Lsize=\*Ovalue] [\*Lparam=\*Oname] [\*Lexp=\*Ovalue]
[\*Lzscale=\*Ovalue]

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.SH 
Flags:
-c Constrain model through central window cell
.SH 
Parameters:
.PP
\*L in \*ORaster surface layer to process
.PP
\*L out \*OOutput raster layer containing morphometric parameter
.PP
\*L s_tol\*O Slope tolerance that defines a `flat' surface (degrees)

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default: 1.0
.PP
\*L c_tol\*O Curvature tolerance that defines `planar' surface

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default: 1.0
.PP
\*L size \*OSize of processing window (odd number only)

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default: 3
.PP
\*L param\*O Morphometric parameter to calculate

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options: elev,slope,aspect,profc,planc,longc,crosc,minic,maxic, feature

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default: elev
.PP
\*L exp\*O Exponent for distance weighting (0.0-4.0)

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default: 0.0
.PP
\*L zscale\*O Vertical scaling factor

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default: 1.0
.PP
 
.PP
\*L\*Wr.param.scale can calculate the following:\*O\*O
.PP
 elev: Generalised elevation value.
.PP
 slope: Maximum gradient at a point.
.PP
 aspect: Direction of maximum gradient.
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 profc: Profile convexity (vertical in direction of steepest slope).
.PP
 planc: Plan convexity (contour curvature).
.PP
 crosc: Cross sectional convexity (tangent to contours, downslope).
.PP
 longc: Longitudinal convexity (perpendicular to contours downslope).
.PP
 minic: Minimum convexity.
.PP
 maxic: Maximum convexity.
.PP
 features: Morphometric features:

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peaks, ridges, passes, channels, pits and planes.

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.SH 
HISTORY
\*C
.DSModified to include constrained fitting. 
Jo Wood, April, 1995 
-------
Modified to include weighting matrix and double precision arithmetic.
Jo Wood, 9th May, 1995.
-------
Modified to include two separate tolerance values for feature detection.
Jo Wood, 23rd May, 1995.

.SH Still to do

Fix bug when `constrain through central cell' option selected. Create colour
tables for all output files (presently only on features).<p>

.SH SEE ALSO
\*W<a href=d.param.scale.html>d.param.scale

.PP
See also Java Code in \*LLandSerf
that implements the same procedure&nbsp;
<ADDRESS>
\*Ljwo@le.ac.uk\*O


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\*LASSIST's home\*O

.SH REFERENCE

Wood, J. (1996): The Geomorphological characterisation of Digital Elevation
Models. Diss., Department of Geography, University of Leicester, U.K. 
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online at:
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<a href=http://www.geog.le.ac.uk/jwo/research/dem_char/thesis/index.html>
            www.geog.le.ac.uk/jwo/research/dem_char/thesis/index.html