as.one: Combine multiple radiocarbon dates assuming they belong to...

In rice: Radiocarbon Equations

Combine multiple radiocarbon dates assuming they belong to the same single year

Description

Combine all calibrated dates by calculating their product for a range of calendar ages, as if all dates belonged to the same (unknown) single calendar age. This assumed that they all belong to the same single year in time. Use with great care, as often dates could stem from material that could have accumulated over a (much) longer time-span, and if so, then the result will be wrong. See Baillie (1991)'s 'suck-in' effect, Journal of Theoretical Archaeology 2, 12-16.

Usage

as.one(
  y,
  er,
  cc = 1,
  postbomb = FALSE,
  deltaR = 0,
  deltaSTD = 0,
  is.F = FALSE,
  as.F = FALSE,
  thiscurve = NULL,
  yrsteps = 1,
  threshold = 0.001,
  normal = TRUE,
  t.a = 3,
  t.b = 4,
  BCAD = FALSE,
  cc.dir = NULL,
  age.lim = c(),
  age.lab = c(),
  d.lim = c(),
  calib.col = rgb(0, 0, 0, 0.2),
  one.col = rgb(0, 0, 1, 0.5),
  one.height = 0.3,
  prob = 0.95,
  talk = TRUE,
  roundby = 0,
  bty = "n"
)

Arguments

y	The set of radiocarbon dates to be tested
er	The lab errors of the radiocarbon dates
cc	Calibration curve to use. Defaults to IntCal20 (cc=1).
postbomb	Whether or not to use a postbomb curve. Required for negative radiocarbon ages.
deltaR	Age offset (e.g. for marine samples).
deltaSTD	Uncertainty of the age offset (1 standard deviation).
is.F	Set this to TRUE if the provided age and error are in the F14C realm.
as.F	Whether or not to calculate ages in the F14C realm. Defaults to as.F=FALSE, which uses the C14 realm.
thiscurve	As an alternative to providing cc and/or postbomb, the data of a specific curve can be provided (3 columns: cal BP, C14 age, error).
yrsteps	Steps to use for interpolation. Defaults to the cal BP steps in the calibration curve
threshold	Report only values above a threshold. Defaults to threshold=1e-6.
normal	Use the normal distribution to calibrate dates (default TRUE). The alternative is to use the t model (Christen and Perez 2016).
t.a	Value a of the t distribution (defaults to 3).
t.b	Value b of the t distribution (defaults to 4).
BCAD	Which calendar scale to use. Defaults to cal BP, BCAD=FALSE.
cc.dir	Directory of the calibration curves. Defaults to where the package's files are stored (system.file), but can be set to, e.g., cc.dir="curves".
age.lim	Limits of the age axis. Calculated automatically by default.
age.lab	Label of the age axis. Defaults to cal BP or BC/AD.
d.lim	Limits of the depth/vertical axis. Calculated automatically by default.
calib.col	The colour of the individual calibrated ages. Defaults to semi-transparent grey.
one.col	The colour of the combined
one.height	The height of the combined distribution
prob	Probability range for highest posterior density (hpd) values. Defaults to prob=0.95.
talk	Whether or not to provide an analysis of the results
roundby	Rounding of reported years. Defaults to 0 decimals
bty	Draw a box around a box of a certain shape. Defaults to bty="n".

Details

This calculates the product of all calibrated probabilities, over the range of calendar ages to which the radiocarbon ages calibrate.

Value

The product of all calibrated probabilities over the range of cal BP years.

Author(s)

Maarten Blaauw

Examples

  data(shroud)
  as.one(shroud$y,shroud$er, BCAD=TRUE) # but note the scatter!
  Zu <- grep("ETH", shroud$ID) # Zurich lab only
  as.one(shroud$y[Zu],shroud$er[Zu], BCAD=TRUE)

rice documentation built on April 11, 2025, 5:53 p.m.