R: Stretch

stretch {terra} | R Documentation

## Stretch

### Description

Linear stretch of values in a SpatRaster object. Provide the desired output range (minv and maxv) and the lower and upper bounds in the original data, either as quantiles (`minq` and `maxq`, or as cell values (`smin` and `smax`). If `smin` and `smax` are both not `NA`, `minq` and `maxq` are ignored.

### Usage

    ## S4 method for signature 'SpatRaster'
    stretch(x, minv=0, maxv=255, minq=0, maxq=1, smin=NA, smax=NA, filename="", ...)

### Arguments

`x` | SpatRaster
`minv` | numeric >= 0 and smaller than maxv. lower bound of stretched value
`maxv` | numeric <= 255 and larger than maxv. upper bound of stretched value
`minq` | numeric >= 0 and smaller than maxq. lower quantile bound of original value. Ignored if smin is supplied
`maxq` | numeric <= 1 and larger than minq. upper quantile bound of original value. Ignored if smax is supplied
`smin` | numeric < smax. user supplied lower value for the layers, to be used instead of a quantile computed by the function itself
`smax` | numeric > smin. user supplied upper value for the layers, to be used instead of a quantile computed by the function itself
`filename` | character. Output filename
`...` | additional arguments for writing files as in `writeRaster`

### Value

SpatRaster

### Examples

    r <- rast(nc=10, nr=10)
    values(r) <- rep(1:25, 4)
    rs <- stretch(r)
    s <- c(r, r*2)
    sr <- stretch(s)

[Package terra version 1.3-22 Index]