caldist {rintcal}

Calculate calibrated distribution

Description

Calculate the calibrated distribution of a radiocarbon date.

Usage

caldist(
  age,
  error,
  cc = 1,
  postbomb = FALSE,
  thiscurve = c(),
  yrsteps = FALSE,
  cc.resample = FALSE,
  dist.res = 200,
  threshold = c(),
  normal = TRUE,
  t.a = 3,
  t.b = 4,
  normalise = TRUE,
  BCAD = FALSE,
  rule = 1,
  cc.dir = NULL
)

Arguments

age

Uncalibrated radiocarbon age

error

Lab error of the radiocarbon age

cc

Calibration curve to use. Defaults to IntCal20 (cc=1).

postbomb

Whether or not to use a postbomb curve. Required for negative radiocarbon ages.

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). Defaults to FALSE.

yrsteps

Steps to use for interpolation. Defaults to the cal BP steps in the calibration curve

cc.resample

The IntCal20 curves have different densities (every year between 0 and 5 kcal BP, then every 5 yr up to 15 kcal BP, then every 10 yr up to 25 kcal BP, and then every 20 yr up to 55 kcal BP). If calibrated ages span these density ranges, their drawn heights can differ, as can their total areas (which should ideally all sum to the same size). To account for this, resample to a constant time-span, using, e.g., cc.resample=5 for 5-yr timespanes.

dist.res

As an alternative to yrsteps, provide the amount of 'bins' in the distribution

threshold

Report only values above a threshold. Defaults to threshold=1e-3 for prebomb dates and threshold=1e-7 for postbomb dates.

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 a of the t distribution (defaults to 4).

normalise

Sum the entire calibrated distribution to 1. Defaults to normalise=TRUE.

BCAD

Which calendar scale to use. Defaults to cal BP, BCAD=FALSE.

rule

Which extrapolation rule to use. Defaults to rule=1 which returns NAs.

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".

Value

The probability distribution(s) as two columns: cal BP ages and their associated probabilities

Examples

calib <- caldist(130,10)
plot(calib, type="l")
postbomb <- caldist(-3030, 20, postbomb=1, BCAD=TRUE)