R: Initialize a SpatRaster with values

initialize {terra} | R Documentation

## Initialize a SpatRaster with values

### Description

Create a SpatRaster with values reflecting a cell property: 'x', 'y', 'col', 'row', 'cell' or 'chess'. Alternatively, a function can be used. In that case, cell values are initialized without reference to pre-existing values. E.g., initialize with a random number (`fun=runif`). While there are more direct ways of achieving this for small objects (see examples) for which a vector with all values can be created in memory, the `init` function will also work for SpatRaster objects with many cells.

### Usage

    ## S4 method for signature 'SpatRaster'
    init(x, fun, filename="", ...)

### Arguments

`x` | SpatRaster
`fun` | function to be applied. This must be a either single number, multiple numbers, a function, or one of a set of known character values. A function must take the number of cells as a single argument to return a vector of values with a length equal to the number of cells, such as `fun=runif`. Allowed character values are 'x', 'y', 'row', 'col', 'cell', and 'chess' to get the x or y coordinate, row, col or cell number or a chessboard pattern (alternating 0 and 1 values)
`filename` | character. Output filename
`...` | additional arguments for writing files as in `writeRaster`

### Value

SpatRaster

### Examples

    r <- rast(ncols=10, nrows=5, xmin=0, xmax=10, ymin=0, ymax=5)
    x <- init(r, fun="cell")
    y <- init(r, fun=runif)

    # initialize with a single value
    z <- init(r, fun=8)

[Package terra version 1.3-22 Index]