Unique values — unique • terra

This method returns the unique values in a SpatRaster, or removes duplicates records (geometry and attributes) in a SpatVector.

Usage

# S4 method for class 'SpatRaster'
unique(x, incomparables=FALSE, digits=NA, na.rm=TRUE, as.raster=FALSE) 

# S4 method for class 'SpatVector'
unique(x, incomparables=FALSE, ...)

Arguments

x: SpatRaster or SpatVector
incomparables: logical. If FALSE and x is a SpatRaster: the unique values are determined for all layers together, and the result is a matrix. If TRUE, each layer is evaluated separately, and a list is returned. If x is a SpatVector this argument is as for a data.frame
digits: integer. The number of digits for rounding the values before finding the unique values. Use NA means to not do any rounding
na.rm: logical. If TRUE, NaN is included if there are any missing values
as.raster: logical. If TRUE, a single-layer categorical SpatRaster with the unique values is returned
...: additional arguments passed on to unique

Value

If x is a SpatRaster: data.frame or list (if incomparables=FALSE)

If x is a SpatVector: SpatVector

Examples

r <- rast(ncols=5, nrows=5)
values(r) <- rep(1:5, each=5)
unique(r)
#>   lyr.1
#> 1     1
#> 2     2
#> 3     3
#> 4     4
#> 5     5
s <- c(r, round(r/3))
unique(s)
#>   lyr.1 lyr.1
#> 1     1     0
#> 2     2     1
#> 3     3     1
#> 4     4     1
#> 5     5     2
unique(s,TRUE)
#> [[1]]
#> [1] 1 2 3 4 5
#> 
#> [[2]]
#> [1] 0 1 2
#> 

unique(s, as.raster=TRUE)
#> class       : SpatRaster 
#> dimensions  : 5, 5, 1  (nrow, ncol, nlyr)
#> resolution  : 72, 36  (x, y)
#> extent      : -180, 180, -90, 90  (xmin, xmax, ymin, ymax)
#> coord. ref. : lon/lat WGS 84 (CRS84) (OGC:CRS84) 
#> source(s)   : memory
#> categories  : label, lyr.1, lyr.1.1 
#> name        : label 
#> min value   :   1_0 
#> max value   :   5_2 


v <- vect(cbind(x=c(1:5,1:5), y=c(5:1,5:1)), 
    crs="+proj=utm +zone=1 +datum=WGS84")
nrow(v)
#> [1] 10
u <- unique(v)
nrow(u)
#> [1] 5

values(v) <- c(1:5, 1:3, 5:4)
unique(v)
#>  class       : SpatVector 
#>  geometry    : points 
#>  dimensions  : 7, 1  (geometries, attributes)
#>  extent      : 1, 5, 1, 5  (xmin, xmax, ymin, ymax)
#>  coord. ref. : +proj=utm +zone=1 +datum=WGS84 +units=m +no_defs 
#>  names       : value
#>  type        : <int>
#>  values      :     1
#>                    2
#>                    3