Skip to contents

Calculate Averages for SpatRasters

Source: R/calculate_average.R
calculate_average.Rd

Calculates temporal averages for a multi-layer SpatRaster. This function serves as a smart wrapper, automatically selecting between an in-memory (`terra`) or out-of-core (`tiled`) workflow based on data size.

Usage

calculate_average(
  x,
  index,
  output_names = NULL,
  output_dir = tempdir(),
  user_region = NULL,
  method = c("auto", "tiled", "terra"),
  tile_degrees = 5,
  gdal_opt = c("COMPRESS=DEFLATE", "PREDICTOR=3", "NUM_THREADS=ALL_CPUS"),
  overwrite = FALSE
)

Arguments

x

A `terra::SpatRaster` object with multiple layers representing a time series.

index

A numeric or integer vector defining the grouping for aggregation. Its length must equal the number of layers in `x`. For example, to average 360 monthly layers into 12 monthly means, `index` would be `rep(1:12, 30)`.

output_names

A character vector of names for the output layers. Its length must equal the number of unique groups in `index`. If `NULL`, names like "avg_unit_1" are generated.

output_dir

The directory where the final averaged raster layers will be saved as GeoTIFF files.

user_region

(Optional) An `sf` or `terra::SpatVector` object for clipping.

method

The processing method: "auto", "tiled", or "terra".

tile_degrees

(Tiled method only) The approximate size of processing tiles.

gdal_opt

(Optional) GDAL creation options for the output GeoTIFFs.

overwrite

Logical. If `FALSE` (default), stops if output files exist.

Value

A `terra::SpatRaster` object pointing to the newly created files.