scoff {terra}

Scale (gain) and offset

Description

These functions can be used to get or set the scale (gain) and offset parameters used to transform values when reading raster data from a file. The parameters are applied to the raw values using the formula below:

value <- value * scale + offset

The default value for scale is 1 and for offset is 0. 'scale' is sometimes referred to as 'gain'.

Note that setting the scale and/or offset are intended to be used with values that are stored in a file. When values are memory, assigning scale or offset values will lead to the immediate computation of new values; in such cases it would be clearer to use Arith-methods.

Usage

## S4 method for signature 'SpatRaster'
scoff(x)

## S4 replacement method for signature 'SpatRaster'
scoff(x)<-value

Arguments

x

SpatRaster

value

two-column matrix with scale (first column) and offset (second column) for each layer. Or NULL to remove all scale and offset values

Value

matrix or changed SpatRaster

Examples

 
r <- rast(system.file("ex/elev.tif", package="terra"))
minmax(r)
scoff(r)
r[4603]

scoff(r) <- cbind(10, 5)
minmax(r)
scoff(r)
r[4603]