scoff: Scale (gain) and offset

In terra: Spatial Data Analysis

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]

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