ifelse for SpatRasters — ifel • terra

Implementation of ifelse for SpatRasters. This method allows for a concise expression of what can otherwise be achieved with a combination of classify, mask, and cover.

ifel is an R equivalent to the Con method in ArcGIS (arcpy).

Usage

# S4 method for class 'SpatRaster'
ifel(test, yes, no, filename="", ...)

Arguments

test: SpatRaster with logical (TRUE/FALSE) values
yes: SpatRaster or numeric
no: SpatRaster or numeric
filename: character. Output filename
...: additional arguments for writing files as in writeRaster

Value

SpatRaster

Examples

r <- rast(nrows=5, ncols=5, xmin=0, xmax=1, ymin=0, ymax=1)
values(r) <- c(-10:0, NA, NA, NA, 0:10)

x <- ifel(r > 1, 1, r)
# same as 
a <- classify(r, cbind(1, Inf, 1))
# or
b <- app(r, fun=function(i) {i[i > 1] <- 1; i})
# or 
d <- clamp(r, -Inf, 1)
# or (not recommended for large datasets)
e <- r
e[e>1] <- 1

## other examples
f <- ifel(is.na(r), 100, r)

z <- ifel(r > -2 & r < 2, 100, 0)

# nested expressions
y <- ifel(r > 1, 1, ifel(r < -1, -1, r))

k <- ifel(r > 0, r+10, ifel(r < 0, r-10, 3))