subset function

Subset a SpatRaster or a SpatVector

Select a subset of layers from a SpatRaster or select a subset of records (row) and/or variables (columns) from a SpatVector.

## S4 method for signature 'SpatRaster'
subset(x, subset, negate=FALSE, NSE=FALSE, filename="", overwrite=FALSE, ...)

## S4 method for signature 'SpatVector'
subset(x, subset, select, drop=FALSE, NSE=FALSE)

Arguments

• x: SpatRaster or SpatVector

• subset: if x is a SpatRaster: integer or character to select layers

  if x is a SpatVector: logical expression indicating the rows to keep (missing values are taken as FALSE)

• select: expression, indicating columns to select

• negate: logical. If TRUE all layers that are not in the subset are selected

• NSE: logical. If TRUE, non-standard evaluation (the use of unquoted variable names) is allowed. Set this to FALSE when calling subset from a function

• drop: logical. If TRUE, the geometries will be dropped, and a data.frame is returned

• filename: character. Output filename

• overwrite: logical. If TRUE, filename is overwritten

• ...: additional arguments for writing files as in writeRaster

Returns

if x is a SpatRaster: SpatRaster

if x is a SpatVector: SpatVector or, if drop=TRUE, a data.frame.

Examples

### SpatRaster
s <- rast(system.file("ex/logo.tif", package="terra"))   
subset(s, 2:3)
subset(s, c(3,2,3,1))

#equivalent to 
s[[ c(3,2,3,1) ]]

s[[c("red", "green")]]
s$red

# expression based (partial) matching of names with single brackets
s["re"]
s["^re"]

# not with double brackets
# s[["re"]]

### SpatVector

v <- vect(system.file("ex/lux.shp", package="terra"))

subset(v, v$NAME_1 == "Diekirch", c("NAME_1", "NAME_2"))

subset(v, NAME_1 == "Diekirch", c(NAME_1, NAME_2), NSE=TRUE)

# or like this
v[2:3,]
v[1:2, 2:3]
v[1:2, c("NAME_1", "NAME_2")]