Luminescence (version 0.8.6)

calc_Lamothe2003: Apply fading correction after Lamothe et al., 2003

Description

This function applies the fading correction for the prediction of long-term fading as suggested by Lamothe et atl., 2003. The function basically adjusts the Ln/Tn values and fit a new dose-response curve using the function plot_GrowthCurve.

Usage

calc_Lamothe2003(object, dose_rate.envir, dose_rate.source, g_value,
  tc = NULL, tc.g_value = tc, verbose = TRUE, plot = TRUE, ...)

Arguments

object

'>RLum.Results data.frame (required): Input data for applying the fading correction. Alow are (1) data.frame with three columns (dose, De, De error), (2) '>RLum.Results object created by the function analyse_SAR.CWOSL or analyse_pIRIRSequence

dose_rate.envir

numeric vector of length 2 (required): Environmental dose rate in mGy/a

dose_rate.source

numeric vector of length 2 (required): Irradiation source dose rate in Gy/s

g_value

numeric vector of length 2 (required): g_value in %/decade recalculated at the moment the equivalent dose was calculated, i.e. tc is either similar for the g-value measurement and the De measurement or needs be to recalculated (cf. calc_FadingCorr). Inserting a normalised g-value, e.g., normalised to 2-days , will lead to wrong results

tc

numeric (optional): time in seconds between irradiation and the prompt measurement used in the De estimation (cf. Huntley & Lamothe 2001). If set to NULL it is assumed that tc is similar for the equivalent dose estimation and the g-value estimation

tc.g_value

numeric (with default): the time in seconds between irradiation and the prompt measurement used for estimating the g-value. If the g-value was normalised to, e.g., 2 days, this time in seconds (i.e., 172800) should be given here along with the time used for the De estimation. If nothing is provided the time is set to tc, which is usual case for g-values obtained using the SAR method and g-values that had been not normalised to 2 days. Note: If this value is not NULL the functions expects a numeric value for tc.

verbose

logical (with default): Enables/disables terminal verbose mode

plot

logical (with default): Enables/disables plot output

...

further arguments passed to the function plot_GrowthCurve

Value

The function returns are graphical output produced by the function plot_GrowthCurve and an '>RLum.Results.

----------------------------------- [ NUMERICAL OUTPUT ] -----------------------------------

RLum.Results-object

slot: @data

Element	Type	Description
$data	data.frame	the fading corrected values
$fit	nls	the object returned by the dose response curve fitting

'slot: @info

The original function call

Function version

0.1.0 (2018-02-02 18:20:28)

How to cite

Kreutzer, S., Mercier, N. (2018). calc_Lamothe2003(): Apply fading correction after Lamothe et al., 2003. Function version 0.1.0. In: Kreutzer, S., Burow, C., Dietze, M., Fuchs, M.C., Schmidt, C., Fischer, M., Friedrich, J. (2018). Luminescence: Comprehensive Luminescence Dating Data Analysis. R package version 0.8.6. https://CRAN.R-project.org/package=Luminescence

References

Huntley, D.J., Lamothe, M., 2001. Ubiquity of anomalous fading in K-feldspars and the measurement and correction for it in optical dating. Canadian Journal of Earth Sciences 38, 1093-1106.

Lamothe, M., Auclair, M., Hamzaoui, C., Huot, S., 2003. Towards a prediction of long-term anomalous fadingof feldspar IRSL. Radiation Measurements 37, 493-498.

See Also

plot_GrowthCurve, calc_FadingCorr, analyse_SAR.CWOSL, analyse_pIRIRSequence

Examples

# NOT RUN {
##load data
##ExampleData.BINfileData contains two BINfileData objects
##CWOSL.SAR.Data and TL.SAR.Data
data(ExampleData.BINfileData, envir = environment())

##transform the values from the first position in a RLum.Analysis object
object <- Risoe.BINfileData2RLum.Analysis(CWOSL.SAR.Data, pos=1)

##perform SAR analysis and set rejection criteria
results <- analyse_SAR.CWOSL(
object = object,
signal.integral.min = 1,
signal.integral.max = 2,
background.integral.min = 900,
background.integral.max = 1000,
verbose = FALSE,
plot = FALSE,
onlyLxTxTable = TRUE
)

##run fading correction
results_corr <- calc_Lamothe2003(
  object = results,
  dose_rate.envir =  c(1.676 , 0.180),
  dose_rate.source = c(0.184, 0.003),
  g_value =  c(2.36, 0.6),
  plot = TRUE,
  fit.method = "EXP")


# }