# unique: Unique values In terra: Spatial Data Analysis

 unique R Documentation

## Unique values

### Description

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

### Usage

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

## S4 method for signature '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)
s <- c(r, round(r/3))
unique(s)
unique(s,TRUE)

unique(s, as.raster=TRUE)

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

values(v) <- c(1:5, 1:3, 5:4)
unique(v)
``````

terra documentation built on Oct. 13, 2023, 5:08 p.m.