This function implements a number of methods for deriving a single point
estimate of calendar age from calibrated radiocarbon dates. Note that none of
these methods produce a good estimate (Michczyński 2007)
,
and should only be used as a last resort if the probability distribution
function or an interval estimate is not appropriate, in which case
method = "mode"
(the default) is recommended.
Usage
cal_point(
x,
method = c("mode", "median", "mean", "local_mode", "central"),
interval = 0.954
)
Arguments
- x
cal
object. A vector of calibrated radiocarbon dates.- method
Character. Method of estimation:
"mode"
(default)age corresponding to the maximum peak of the probability distribution
"median"
age corresponding to the median quantile of the probability distribution
"mean"
mean age weighted by probability density
"local_mode"
age corresponding to the maximum peak of the probability distribution within the confidence range specified by
interval
(not yet implemented)"central"
age corresponding to the central point of the probability density within the confidence range specified by
interval
(not yet implemented)
- interval
Numeric. Only used for
method = "local_mode"
andmethod = "central"
.
References
Michczyński A (2007). “Is it Possible to Find a Good Point Estimate of a Calibrated Radiocarbon Date?” Radiocarbon, 49(2), 393--401. ISSN 0033-8222, 1945-5755, doi:10.1017/S0033822200042326 .
Examples
cal_point(c14_calibrate(10000, 30))
#> # cal BP years <yr[1]>:
#> [1] 11400
#> # Era: Before Present (cal BP): Gregorian years (365.2425 days), counted backwards from 1950