Luminescence (version 0.3.1)

calc_FuchsLang2001: Apply the model after Fuchs & Lang (2001) to a given De distribution.

Description

This function applies the method according to Fuchs & Lang (2001) for heterogeneously bleached samples with a given coefficient of variation threshold.

Usage

calc_FuchsLang2001(sample, 
                   sample.mtext = "unknown sample", 
                   sample.id = sample.mtext, 
                   cvThreshold = 5, 
                   startDeValue = 1, 
                   output.plot = TRUE, output.terminal = TRUE, 
                   main = "Fuchs & Lang (2001)", 
                   xlab = expression(paste(D[e], " [Gy]")), 
                   cex.global = 1)

Arguments

sample

data.frame (required): two column data frame, e.g. De and De error

sample.mtext

character (optional): mtext for optional plot (top)

sample.id

character (with default): sample id, with default the sample.mtext is used.

cvThreshold

numeric (with default): coefficient of variation in percent, as threshold for the method, e.g. cvThreshold = 3. See details.

startDeValue

numeric (with default): number of the first aliquot that is used for the calculations

output.plot

logical (with default): plot output TRUE/FALSE

output.terminal

logical (with default): terminal output TRUE/FALSE

main

character (with default): title of the plot (works as in plot)

xlab

character (with default): xlab works as in plot

cex.global

numeric (with default): global scaling factor

Value

• A plot and terminal output is provided if desired. In addition, a list is returned containing two elements:
• results
  data.frame with stastical parameters, e.g. mean, sd, ...
• usedDeValues
  data.frame containing the used values for the calculation

Details

Used values If the coefficient of variation (c[v]) of the first two values is larger than the threshold c[v_threshold], the first value is skipped. Use the startDeValue argument to define a start value for calculation (e.g. 2nd or 3rd value). Basic steps of the approach (1) Estimate natural relative variation of the sample using a dose recovery test

(2) Sort the input values ascendingly

(3) Calculate a running mean, starting with the lowermost two values and add values iteratively.

(4) Stop if the calculated c[v] exceeds the specified cvThreshold

References

Fuchs, M. & Lang, A., 2001. OSL dating of coarse-grain fluvial quartz using single-aliqout protocols on sediments from NE Peloponnese, Greece. In: Quaternary Science Reviews (20), pp. 783-787.

Fuchs, M. & Wagner, G.A., 2003. Recognition of insufficient bleaching by small aliquots of quartz for reconstructing soil erosion in Greece. Quaternary Science Reviews, 22, pp. 1161-1167.

See Also

plot

Examples

##load example data
data(ExampleData.DeValues)

##calculate De according to Fuchs & Lang (2001)
calc_FuchsLang2001(ExampleData.DeValues, cvThreshold = 5)