  Estimates the Mean Ceramic Date of an assemblage.

mcd(object, dates, ...)

# S4 method for CountMatrix,numeric
mcd(object, dates)

# S4 method for MeanDate
bootstrap(
object,
level = 0.95,
type = c("student", "normal"),
probs = c(0.25, 0.5, 0.75),
n = 1000
)

# S4 method for MeanDate
jackknife(object)

## Arguments

object

A arkhe::CountMatrix or a MeanDate object.

dates

A numeric vector of dates.

...

Currently not used.

level

A length-one numeric vector giving the confidence level. Must be a single number between $$0$$ and $$1$$. If NULL, no confidence interval are computed.

type

A character string giving the type of confidence interval to be returned. It must be one "student" (default) or "normal". Any unambiguous substring can be given. Only used if level is not NULL.

probs

A numeric vector of probabilities with values in $$[0,1]$$ (see stats::quantile()). If NULL, quantiles are not computed.

n

A non-negative integer giving the number of bootstrap replications.

## Value

• mcd() returns a MeanDate object.

• bootstrap() and jackknife() return a data.frame.

## Details

The Mean Ceramic Date (MCD) is a point estimate of the occupation of an archaeological site (South 1977). The MCD is estimated as the weighted mean of the date midpoints of the ceramic types (based on absolute dates or the known production interval) found in a given assemblage. The weights are the relative frequencies of the respective types in the assemblage.

A bootstrapping procedure is used to estimate the confidence interval of a given MCD. For each assemblage, a large number of new bootstrap replicates is created, with the same sample size, by resampling the original assemblage with replacement. MCDs are calculated for each replicates and upper and lower boundaries of the confidence interval associated with each MCD are then returned.

South, S. A. (1977). Method and Theory in Historical Archaeology. New York: Academic Press.