Apply Season-Masked Sum — wapor_masked

Computes weighted sum of a raster time series using per-dekad season weights.

Usage

wapor_masked_sum(x, weights, layer_multipliers = NULL, incremental = FALSE)

x: SpatRaster. Multi-layer raster (e.g., dekadal AETI or RET).
weights: SpatRaster. Season weights (0-1), same number of layers as x.
layer_multipliers: Optional numeric vector of per-layer multipliers. Use this for rate variables stored per day where a weighted sum must be multiplied by the full slice length.
incremental: Logical. If TRUE, performs aggregation layer-by-layer to save memory. Recommended for very long seasons or low RAM. Default FALSE.

A single-layer SpatRaster of weighted sums.