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focalWeight

Focal weights matrix

Description

Calculate focal ("moving window") weight matrix for use in the focal function. The sum of the values adds up to one.

Usage

focalWeight(x, d, type=c('circle', 'Gauss', 'rectangle'))

Arguments

x

Raster* object
d

numeric. If type=circle, the radius of the circle (in units of the CRS). If type=rectangle the dimension of the rectangle (one or two numbers). If type=Gauss the size of sigma, and optionally another number to determine the size of the matrix returned (default is 3 times sigma)
type

character indicating the type of filter to be returned

Value

matrix that can be used in focal

Examples

r <- raster(ncols=36, nrows=18, xmn=0)
# Gaussian filter for square cells
gf <- focalWeight(r, 2, "Gauss")
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

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