raster (version 1.7-23)

Gain and offset: Gain and offset of values on file

Description

These functions can be used to get or set the gain and offset parameters used to transform values when reading from a file (currently these are ignored when writing a file). The gain and offset parameters are applied to the raw values using the formula below: value <- value * gain + offset The default value for gain is 1 and for offset is 0. 'gain' is sometimes referred to as 'scale'. Note that setting gain and/or offset only affects reading of values from a file, it does not change values that are already (or only) in memory.

Usage

gain(x)
gain(x) <- value
offs(x)
offs(x) <- value

Arguments

x

Raster* object

value

Single numeric value

Value

• Raster* object or numeric value(s)

Examples

r <- raster(system.file("external/test.grd", package="raster"))
gain(r)
offs(r)
r[1505:1510]
gain(r) <- 10
offs(r) <- 5
r[1505:1510]