Limit range of values in a SpatRaster object

Shorthand for limiting maximum and minimum values in a SpatRaster-class object.

Usage

limit(x, y = NULL, min = NULL, max = NULL)

Arguments

x

Object to limit, a SpatRaster-class object.

y

Either a range (i.e. a numeric vector with two values), or data.frame with positioned color values (column z indicates values), or a calibrated ramp (e.g. produced with expand).

min

If y is not given, the minimum value to have in the data.frame.

max

If y is not given, the maximum value to have in the data.frame.

Value

A SpatRaster object.

Examples

# This function relies on the terra extension
if(requireNamespace("terra", quietly=TRUE)){
 library(terra)
  # Example 1. Using specific values
  # a SpatRaster object
  r<- terra::rast()
  # populate with a Gaussian distribution
  terra::values(r) <- rnorm(terra::ncell(r), 0.5,1 )
  # and limit
  rLimit <- limit(r, min=-0.2, max=0.2)
  plot(rLimit)


  # Example 2. Using an expanded color ramp
  # Create a data.frame
  df <- data.frame(
    z=c(-1, -0.2, 0, 0.2, 1),
    color=rev(gradinv(5))
  )
  ramp <- expand(df, n=200)
  rLimited <- limit(r, y=ramp)
  # default
  plot(rLimited)

  # manual ramping.
  plot(rLimited, breaks=ramp$breaks, col=ramp$col,
    legend=FALSE)

  # temporary solution for manual legend
  # Marginal ramps will be implemented later
  ramplegend(x=140, y=90, ramp=ramp, cex=0.5,
    at=c(-1, 0, 1), label=c("< -1", 0, "> +1"))


}
#> terra 1.8.54