boundaries: Detect boundaries (edges)

In terra: Spatial Data Analysis

Detect boundaries (edges)

Description

Detect boundaries (edges). Boundaries are cells that have more than one class in the 4 or 8 cells surrounding it, or, if classes=FALSE, cells with values and cells with NA.

Usage

## S4 method for signature 'SpatRaster'
boundaries(x, classes=FALSE, inner=TRUE, 
         directions=8, falseval=0, filename="", ...)

Arguments

x	SpatRaster
inner	logical. If TRUE, "inner" boundaries are returned, else "outer" boundaries are returned
classes	character. Logical. If TRUE all different values are (after rounding) distinguished, as well as NA. If FALSE (the default) only edges between NA and non-NA cells are considered
directions	integer. Which cells are considered adjacent? Should be 8 (Queen's case) or 4 (Rook's case)
falseval	numeric. The value to use for cells that are not a boundary and not NA
filename	character. Output filename
...	options for writing files as in writeRaster

Value

SpatRaster. Cell values are either 1 (a border) or 0 (not a border), or NA

See Also

focal, patches

Examples

r <- rast(nrows=18, ncols=36, xmin=0)
r[150:250] <- 1
r[251:450] <- 2
bi <- boundaries(r)
bo <- boundaries(r, inner=FALSE)
bc <- boundaries(r, classes=TRUE)
#plot(bc)

terra documentation built on Oct. 14, 2024, 5:07 p.m.