raster: mask – R documentation

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mask

Mask values in a Raster object

Description

Create a new Raster* object that has the same values as x, except for the cells that are NA (or other maskvalue) in a 'mask'. These cells become NA (or other updatevalue). The mask can be either another Raster* object of the same extent and resolution, or a Spatial* object (e.g. SpatialPolygons) in which case all cells that are not covered by the Spatial object are set to updatevalue. You can use inverse=TRUE to set the cells that are not NA (or other maskvalue) in the mask, or not covered by the Spatial* object, to NA (or other updatvalue).

Usage

## S4 method for signature 'RasterLayer,RasterLayer'
mask(x, mask, filename="", inverse=FALSE, 
      maskvalue=NA, updatevalue=NA, updateNA=FALSE, ...)

## S4 method for signature 'RasterStackBrick,RasterLayer'
mask(x, mask, filename="", inverse=FALSE,
      maskvalue=NA, updatevalue=NA, updateNA=FALSE, ...)

## S4 method for signature 'RasterLayer,RasterStackBrick'
mask(x, mask, filename="", inverse=FALSE, 
      maskvalue=NA, updatevalue=NA, updateNA=FALSE, ...)

## S4 method for signature 'RasterStackBrick,RasterStackBrick'
mask(x, mask, filename="", inverse=FALSE, 
      maskvalue=NA, updatevalue=NA, updateNA=FALSE, ...)

## S4 method for signature 'Raster,Spatial'
mask(x, mask, filename="", inverse=FALSE, 
      updatevalue=NA, updateNA=FALSE, ...)

Arguments

`x`	Raster* object
`mask`	Raster* object or a Spatial* object
`filename`	character. Optional output filename
`inverse`	logical. If `TRUE`, areas on mask that are _not_ the `maskvalue` are masked
`maskvalue`	numeric. The value in `mask` that indicates the cells of `x` that should become `updatevalue` (default = `NA`)
`updatevalue`	numeric. The value that cells of `x` should become if they are not covered by `mask` (and not `NA`)
`updateNA`	logical. If `TRUE`, `NA` values outside the masked area are also updated to the the `updatevalue` (only relevant if the `updatevalue` is not `NA`
`...`	additional arguments as in `writeRaster`

Value

Raster* object

Examples

r <- raster(ncol=10, nrow=10)
m <- raster(ncol=10, nrow=10)
values(r) <- runif(ncell(r)) * 10
values(m) <- runif(ncell(r))
m[m < 0.5] <- NA
mr <- mask(r, m)

m2 <- m > .7
mr2 <- mask(r, m2, maskvalue=TRUE)

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