mask function

Mask values in a Raster object

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). methods

## 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

Returns

Raster* object

See Also

rasterize, crop

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)