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Convert a List of Layers into a RasterStack of Predictors

Source: R/toPredictors.R
toPredictors.Rd

This function converts a list of raster layers into a SpatRaster object, aligning them to a common reference grid for spatial analysis. It allows for resampling of the layers to match a specified reference layer and assigns appropriate names to the resulting raster stack.

Usage

toPredictors(layerList, layerNames = NULL, reference = NULL)

Arguments

layerList

A list of raster layers (SpatRaster objects) to be combined into a SpatRaster stack. These layers should represent different environmental variables or predictors.

layerNames

An optional character vector specifying names for the layers in the resulting SpatRaster. If not provided, the function will attempt to derive names from the input list.

reference

An optional reference layer (SpatRaster) to which all layers in layerList will be resampled. If not provided, the first layer in layerList will be used as the reference.

Value

A SpatRaster object where all layers have been resampled to match the reference layer and assigned appropriate names.

Details

The function first checks if layerNames are provided or if they can be derived from the layerList. If the length of layerNames does not match the length of layerList, the function will stop and return an error.

If no reference layer is provided, the function will use the first layer in layerList as the reference for resampling. Each layer in layerList is then resampled to match the reference layer's resolution and extent. The resulting raster layers are combined into a SpatRaster stack, which can be used as input for further spatial analysis or modeling.

Note

The function uses parallel processing to speed up the resampling process when dealing with large datasets.

Examples

library(terra)

# Example raster layers
r1 <- rast(nrows=10, ncols=10)
r2 <- rast(nrows=10, ncols=10)
values(r1) <- runif(ncell(r1))
values(r2) <- runif(ncell(r2))

# Convert to list
layers <- list(r1, r2)

# Use the first layer as reference for resampling
predictors <- toPredictors(layers)
#> IMPORTANT!
#> First layer will be used as reference for resampling

# Check the names and extent
names(predictors)
#> [1] "lyr.1" "lyr.1"
ext(predictors)
#> SpatExtent : -180, 180, -90, 90 (xmin, xmax, ymin, ymax)