modelDates: Perform regression of archaeological dates on great circle...

Description Usage Arguments Value Examples

View source: R/spDates.R

Description

Perform regression of archaeological dates on great circle distances from a hypothetical origin. Dates can be filtered to retain only the earliest dates per distance bins (Hamilton and Buchanan 2007). Bootstrap is executed to account for uncertainty in calibrated dates. If a cost surface is provided, distances are calculated using least cost paths instead of great circle distances. Regression can be either reduced major axis or ordinary least squares. If using ordinary least squares, regression is performed both on time-versus-distance and on distance-versus-time.

Usage

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modelDates(
  ftrSites,
  c14bp,
  origin,
  binWidth = 0,
  nsim = 999,
  cost = NULL,
  method = "rma",
  ncores = 1
)

Arguments

ftrSites

A SpatialPointsDataFrame object with associated earliest C14 dates per site and respective calibrated distributions (CalDates objects) in a field named "cal". Result of applying filterDates() and calAll().

c14bp

A string. Name of the field with the radiocarbon ages in C14 BP format.

origin

A SpatialPointsDataFrame object. The site considered as hypothetical origin of expansion.

binWidth

A number. Width of the spatial bins in km, calculated as distance intervals from the hypothetical origin. Default is 0 (no bins).

nsim

A number. Number of simulations to be run during the bootstrapping procedure. Default is 999.

cost

Optional. A RasterLayer with friction values to calculate least cost path distances instead of great circle distances.

method

A string. Method to be used in the regression. One of "rma" or "ols". Default is "rma".

ncores

A number. Number of cores used for parallel processing. Default is 1.

Value

a dateModel object.

Examples

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data(neof)
data(centers)
jericho <- centers[centers$Site=="Jericho",]
model <- modelDates(neof, "C14Age", jericho, method="ols")

jgregoriods/spDates documentation built on Oct. 10, 2020, 1:18 p.m.