makecumsumSurface: Create cumulative sum probability surface

In isocat: Isotope Origin Clustering and Assignment Tools

Create cumulative sum probability surface

Description

Converts normalized probability surface (e.g. one layer output of isotopeAssignmentModel function) to cumulative sum surfaces, i.e., one where the new value of a given cell is equal to the sum of all old values less than or equal to the old value of the cell.

Usage

makecumsumSurface(indivraster, rescale = FALSE, rename = FALSE)

Arguments

indivraster	Normalized probability surface SpatRaster
rescale	Rescale between 0 and 1? Defaults to FALSE.
rename	Character value to append to raster name (e.g. "_odds"). Defaults to FALSE.

Value

Returns SpatRaster rescaled to Cumulative Sum values.

See Also

cumsumAtSamplingLocation

Examples

# Generate example probability surfaces. The isoscape is coarsened here so the
# example runs quickly; cumsumbelow() scales with the square of the cell count.
myiso    <- terra::aggregate(rast(isoscape,    type = "xyz"), 5)
myiso_sd <- terra::aggregate(rast(isoscape_sd, type = "xyz"), 5)
df <- data.frame(
        ID = c(-100, -80, -50),
        isotopeValue = c(-100, -80, -50),
        SD_indv = rep(5, 3)
        )
assignmentModels <- isotopeAssignmentModel(
        ID = df$ID,
        isotopeValue = df$isotopeValue,
        SD_indv = df$SD_indv,
        precip_raster = myiso,
        precip_SD_raster = myiso_sd,
        nClusters = FALSE
        )

# Convert to cumulative sum surface.
cumulative_sum_surface <- terra::rast(
     lapply( terra::as.list( assignmentModels ), makecumsumSurface )
     )
plot(cumulative_sum_surface)

isocat documentation built on July 9, 2026, 5:10 p.m.