dbED: Summarizing the distribution of equivalent dose values

Description

Calculating statistical parameters, such as average, standard deviation, skewness, kurtosis, over-dispersion, homogeneity test of equivalent dose values, supporting histogram and probability density plot drawing.

Usage

dbED(EDdata, aliquot=c("sa","sg"), plot = TRUE, from = NULL, 
     to = NULL, step = 0.1, nbin = 15, samplename = NULL)

Arguments

EDdata

data.frame(required): equivalent doses and associated errors (a total of two columns), the same as that in function RadialPlotter

aliquot

character(with default): single-aliquot ("sa") or single-grain ("sg"), default aliquot="sa"

plot

logical(with default): whether drawing histogram and probability density plot or not

from

numeric(optional): the desired lower limit of x-axis

numeric(optional): the desired upper limit of x-axis

step

numeric(with default): step size for generating a vector, from which densities of normal distributions will be calculated and summing up as the whole probability curve. Finer step gives smoother curve

nbin

numeric(with default): the desired number of intervals of the histogram

samplename

character(optional): the name of the sample

Value

Return a list that contains following elements:
summaryEDa basic summary of equvalent dose values
mlpEDmean of the lowest percent [x] of equivalent dose values (Olley et al, 1998)
homogeneityresults of simple homogeneity test (Galbraith, 2003)
skewnessskewness of equivalent dose values
kurtosiskurtosis of equivalent dose values
proposala proposed statistical age model (Bailey and Arnold, 2006; Arnold et al, 2007) that depends on used aliquot type ("sg" or "sa"), on which could not be relied absolutely

References

Olley, J.M., Caitcheon, G., Murray, A.S., 1998. The distribution of apparent dose as determined by optically stimulated luminescence in small aliquots of fluvial quartz: implications for dating young sediments. Quaternary Geochronology, 17, pp.1033-1040.

Galbraith, R., 2003. A simple homogeneity test for estimates of dose obtained using OSL. Ancient TL, 21(2), pp.75-77.

Bailey, R.M., Arnold, L.J., 2006. Statistical modelling of single grain quartz De distributions and an assessment of procedures for estimating burial dose. Quaternary Science Reviews, 25 (19-20), pp. 2475-2502.

Arnold, L.J., Bailey, R.M., Tucher, G.E., 2007. Statistical treatment of fluvial dose distributions from southern Colorado arroyo deposits. Quaternary Geochronology, 2, pp.162-167.

Duller, G.A.T., 2008. Single-grain optical dating of Quaternary sediments: why aliquot size matters in luminescence dating. Boreas, 37 (4), pp.589-612.

Examples

Run this code

# Loading EDdata
 data(EDdata)
# Analyzing equivalent dose values of sample AL3
 dbED(EDdata[[2]])