rcarbon (version 1.4.0)

uncalibrate: Uncalibrate (back-calibrate) a calibrated radiocarbon date (or summed probability distribution).

Description

Function for uncalibrating one or more radiocarbon dates.

Usage

uncalibrate(x, ...)
# S3 method for default
uncalibrate(x, CRAerrors = 0, roundyear = TRUE, calCurves = "intcal20", ...)
# S3 method for CalGrid
uncalibrate(
  x,
  calCurves = "intcal20",
  eps = 1e-05,
  compact = TRUE,
  verbose = TRUE,
  ...
)

Arguments

x

Either a vector of calibrated radiocarbon ages or an object of class CalGrid.

...

ignored

CRAerrors

A vector of standard deviations corresponding to each estimated radiocarbon age (ignored if x is a CalGrid object).

roundyear

An optional vector of IDs for each date (ignored if x is a CalGrid object).

calCurves

A string naming a calibration curve already provided with the rcarbon package (currently 'intcal20','intcal13','intcal13nhpine16','shcal20','shcal13','shcal13shkauri16',''marine13','marine20' and 'normal') or a custom curve provided as matrix/data.frame in three columns ("CALBP","C14BP","Error"). The default is the 'intcal20' curve and only one curve can currently be specified for all dates.

eps

Cut-off value for density calculation (for CalGrid objects only).

compact

A logical variable indicating whether only uncalibrated ages with non-zero probabilities should be returned (for CalGrid objects only).

verbose

A logical variable indicating whether extra information on progress should be reported (for CalGrid objects only).

Value

A data.frame with specifying the original data, the uncalibrated age without the calibration curve error (ccCRA), the calibration curve error at this point in the curve (ccError), a randomised uncalibrated age (rCRA) given both the stated ccError and any further hypothesised instrumental error provided by the CRAerrors argument (rError).

Details

This function takes one or more calibrated calendars and looks-up the corresponding uncalibrated age, error of the stated calibration curve at that point. It also provides a randomised estimate of the uncalibrate age based on the curve error (and optionally also a hypothetical measurement error.

Examples

# NOT RUN {
# Uncalibrate two calendar dates
uncalibrate(c(3050,2950))
# }