raster: hillShade – R documentation

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hillShade

Hill shading

Description

Compute hill shade from slope and aspect layers (both in radians). Slope and aspect can be computed with function terrain.

A hill shade layer is often used as a backdrop on top of which another, semi-transparent, layer is drawn.

Usage

hillShade(slope, aspect, angle=45, direction=0, filename='', normalize=FALSE, ...)

Arguments

`slope`	RasterLayer object with slope values (in radians)
`aspect`	RasterLayer object with aspect values (in radians)
`angle`	The the elevation angle of the light source (sun), in degrees
`direction`	The direction (azimuth) angle of the light source (sun), in degrees
`filename`	Character. Optional filename
`normalize`	Logical. If `TRUE`, values below zero are set to zero and the results are multiplied with 255
`...`	Standard additional arguments for writing RasterLayer files

Author(s)

Andrew Bevan, Robert J. Hijmans

References

Horn, B.K.P., 1981. Hill shading and the reflectance map. Proceedings of the IEEE 69(1):14-47

Examples

## Not run: 
alt <- getData('alt', country='CHE')
slope <- terrain(alt, opt='slope')
aspect <- terrain(alt, opt='aspect')
hill <- hillShade(slope, aspect, 40, 270)
plot(hill, col=grey(0:100/100), legend=FALSE, main='Switzerland')
plot(alt, col=rainbow(25, alpha=0.35), add=TRUE)

## End(Not run)

raster

Geographic Data Analysis and Modeling

v3.4-10

GPL (>= 3)

Authors

Robert J. Hijmans [cre, aut] (<https://orcid.org/0000-0001-5872-2872>), Jacob van Etten [ctb], Michael Sumner [ctb], Joe Cheng [ctb], Dan Baston [ctb], Andrew Bevan [ctb], Roger Bivand [ctb], Lorenzo Busetto [ctb], Mort Canty [ctb], Ben Fasoli [ctb], David Forrest [ctb], Aniruddha Ghosh [ctb], Duncan Golicher [ctb], Josh Gray [ctb], Jonathan A. Greenberg [ctb], Paul Hiemstra [ctb], Kassel Hingee [ctb], Institute for Mathematics Applied Geosciences [cph], Charles Karney [ctb], Matteo Mattiuzzi [ctb], Steven Mosher [ctb], Babak Naimi [ctb], Jakub Nowosad [ctb], Edzer Pebesma [ctb], Oscar Perpinan Lamigueiro [ctb], Etienne B. Racine [ctb], Barry Rowlingson [ctb], Ashton Shortridge [ctb], Bill Venables [ctb], Rafael Wueest [ctb]

Initial release

2021-05-02