Description Usage Arguments Details Value References Examples
Function for calibrating radiocarbon dates or uncalibrated SPDs.
Function for calibrating a SPD generated by summing uncalibrated dates.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34  calibrate(x, ...)
## Default S3 method:
calibrate(
x,
errors,
ids = NA,
dateDetails = NA,
calCurves = "intcal20",
resOffsets = 0,
resErrors = 0,
timeRange = c(55000, 0),
normalised = TRUE,
F14C = FALSE,
calMatrix = FALSE,
eps = 1e05,
ncores = 1,
verbose = TRUE,
...
)
## S3 method for class 'UncalGrid'
calibrate(
x,
errors = 0,
calCurves = "intcal20",
timeRange = c(55000, 0),
eps = 1e05,
type = "fast",
datenormalised = FALSE,
spdnormalised = FALSE,
verbose = TRUE,
...
)

x 
A vector of uncalibrated radiocarbon ages or a UncalGrid class object. 
... 
ignored 
errors 
A vector of standard deviations corresponding to each estimated radiocarbon age. 
ids 
An optional vector of IDs for each date. 
dateDetails 
An optional vector of details for each date which will be returned in the output metadata. 
calCurves 
Either a character string naming a calibration curve already provided with the rcarbon package (currently 'intcal20','intcal13','intcal13nhpine16','shcal20','shcal13','shcal13shkauri16',ā€¯marine13','marine20' and 'normal'(i.e. no calibration) are possible; default is 'intcal20') or a custom calibration curve as threecolumn matrix or data.frame (calibrated year BP, uncalibrated age bp, standard deviation). Different existing curves can be specified per dated sample, but only one custom curve can be provided for all dates. 
resOffsets 
A vector of offset values for any marine reservoir effect (default is no offset). 
resErrors 
A vector of offset value errors for any marine reservoir effect (default is no offset). 
timeRange 
Earliest and latest data to calibrate for, in calendar years. Posterior probabilities beyond this range will be excluded (the default is sensible in most cases). 
normalised 
A logical variable indicating whether the calibration should be normalised or not. Default is TRUE. 
F14C 
A logical variable indicating whether calibration should be carried out in F14C space or not. Default is FALSE. 
calMatrix 
a logical variable indicating whether the age grid should be limited to probabilities higher than 
eps 
Cutoff value for density calculation. Default is 1e5. 
ncores 
Number of cores/workers used for parallel execution. Default is 1 (>1 requires doSnow package). 
verbose 
A logical variable indicating whether extra information on progress should be reported. Default is TRUE. 
type 
Currently, two options are available. With "fast", a lookup is conducted for each calendar year that picks up the amplitude of the nearest CRA age. With "full", each CRA is calibrated individually and then summed (much slower). 
datenormalised 
Controls for calibrated dates with probability mass outside the timerange of analysis. If set to TRUE the total probability mass within the timespan of analysis is normalised to sum to unity. Should be set to FALSE when the parameter 
spdnormalised 
A logical variable indicating whether the total probability mass of the SPD is normalised to sum to unity. 
This function computes one or more calibrated radiocarbon ages using the method described in Bronk Ramsey 2008 (see also Parnell 2017). It is possible to specify different calibration curves or reservoir offsets individually for each date, and control whether the resulting calibrated distribution is normalised to 1 underthecurve or not. Calculations can also be executed in parallel to reduce computing time. The function was modified from the BchronCalibrate
function in the Bchron
package developed by A.Parnell (see references below).
An object of class CalDates with the following elements:
metadata
A data.frame containing relevant information regarding each radiocarbon date and the parameter used in the calibration process.
grids
A list of calGrid class objects, containing the posterior probabilities for each calendar year. The most memoryefficient way to store calibrated dates, as only years with nonzero probability are stored, but aggregation methods such as spd()
may then take longer to extract and combine multiple dates. NA when the parameter calMatrix is set to TRUE.
calMatrix
A matrix of probability values, one row per calendar year in timeRange and one column per date. By storing all possible years, not just those with nonzero probability, this approach takes more memory, but speeds up spd() and is suggested whenever the latter is to be used. NA when the parameter calMatrix is set to FALSE.
Bronk Ramsey, C. 2008. Radiocarbon dating: revolutions in understanding, Archaeometry 50.2: 24975. DOI: https://doi.org/10.1111/j.14754754.2008.00394.x
Parnell, A. 2017. Bchron: Radiocarbon Dating, AgeDepth Modelling, Relative Sea Level Rate Estimation, and NonParametric Phase Modelling, R package: https://CRAN.Rproject.org/package=Bchron
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DateID MedianBP OneSigma_BP_1 OneSigma_BP_2 TwoSigma_BP_1
1 1 4476 4517 to 4476 4445 to 4421 4527 to 4413
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