This function applies the fading correction for the prediction of long-term fading as suggested by Lamothe et al., 2003. The function basically adjusts the Ln/Tn values and fit a new dose-response curve using the function plot_GrowthCurve.
calc_Lamothe2003( object, dose_rate.envir, dose_rate.source, g_value, tc = NULL, tc.g_value = tc, verbose = TRUE, plot = TRUE, ... )
object | RLum.Results data.frame (required): Input data for applying the fading correction. Allow are (1) data.frame with three columns (dose, LxTx, LxTx error), (2) RLum.Results object created by the function analyse_SAR.CWOSL or analyse_pIRIRSequence |
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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, which is, according to Lamothe et al. (2003) De/t*. |
g_value | numeric vector of length 2 (required): g_value in \ 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 |
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 |
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 |
The function returns are graphical output produced by the function plot_GrowthCurve and an RLum.Results.
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[ NUMERICAL OUTPUT ]
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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
0.1.0
Kreutzer, S., Mercier, N., 2021. 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., Mercier, N., Riedesel, S., Autzen, M., Mittelstrass, D., Gray, H.J., 2021. Luminescence: Comprehensive Luminescence Dating Data Analysis. R package version 0.9.11. https://CRAN.R-project.org/package=Luminescence
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 fading of feldspar IRSL. Radiation Measurements 37, 493-498.
Sebastian Kreutzer, Geography & Earth Sciences, Aberystwyth University (United Kingdom), Norbert Mercier, IRAMAT-CRP2A, Université Bordeaux Montaigne (France) , RLum Developer Team
##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")#> #> [calc_Lamothe2003()] #> #> Used g_value: 2.36 ± 0.6 %/decade #> #> Fading_C: 0.785 ± 0.055 #> Corrected Ln/Tn: 5.513 ± 0.127 #> Corrected De: 471.3 ± 26.04 Gy #> -------------------------------------------------------- #> Corrected Age: 281.2 ± 33.96 ka #> --------------------------------------------------------