Linear area rebinning of frequency data

Redistributes counts from source bins to destination bins using proportional overlap. For each destination bin, the function finds all source bins that overlap it and assigns a fraction of each source bin's count proportional to the overlap width relative to the source bin width.

Usage

rebin_counts(src_edges, src_counts, dest_edges)

Arguments

src_edges

numeric vector (length N+1). Boundaries of source bins. Must be monotonically increasing.

src_counts

numeric vector (length N). Counts in each source bin. May be an AD vector from RTMB.

dest_edges

numeric vector (length M+1). Boundaries of destination bins. Must be monotonically increasing.

Value

numeric vector (length M). Rebinned counts in destination bins.

Details

AD-safe: src_edges and dest_edges are data; only src_counts may carry AD values. The operation is linear in src_counts.

Examples

# Identity rebin
edges <- 0:5
counts <- c(10, 20, 15, 5, 30)
rebin_counts(edges, counts, edges)
#> [1] 10 20 15  5 30

# Coarsen: merge pairs of bins
src_edges  <- 0:4
src_counts <- c(10, 20, 15, 5)
dest_edges <- c(0, 2, 4)
rebin_counts(src_edges, src_counts, dest_edges)
#> [1] 30 20