makeMultiMonthIsoscape: Make mean multi-month isoscape and error surfaces.

In isocat: Isotope Origin Clustering and Assignment Tools

Make mean multi-month isoscape and error surfaces.

Description

Combines a stack of monthly isoscape maps, monthly isoscape standard error maps, and optionally a precipitation (amount) stack into a single precipitation-weighted mean isoscape and a combined error surface. Each stack must contain layers corresponding to each of the target months.

Usage

makeMultiMonthIsoscape(iso_stack, iso_se_stack, precip_stack = NULL)

Arguments

iso_stack	A SpatRaster containing n layers corresponding to isoscape models for n months.
iso_se_stack	A SpatRaster containing n layers corresponding to isoscape standard error maps for n months.
precip_stack	Either a SpatRaster containing n layers corresponding to precipitation amounts for n months, or NULL (assumes equal precipitation amounts.)

Details

If precip_stack is NULL, equal precipitation amounts are assumed for each month.

Value

A list containing a precipitation-weighted mean isoscape ('mean_iso') and a root-sum-of-square combined error map ('iso_se').

Examples

myiso <- rast(isoscape, type = "xyz")
myiso_sd <- rast(isoscape_sd, type = "xyz")
# Two example "months" derived from the bundled isoscape.
iso_stack    <- c(myiso, myiso + 5)
iso_se_stack <- c(myiso_sd, myiso_sd)
precip_stack <- c(myiso * 0 + 1, myiso * 0 + 3)   # relative weights 1:3
result <- makeMultiMonthIsoscape(iso_stack, iso_se_stack, precip_stack)
plot(result$mean_iso)
plot(result$iso_se)

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