fastED {numOSL} | R Documentation |
Estimating a fast-component equivalent dose using decay curves obtained from the single aliquot regenerative-dose (SAR) method.
fastED(Sigdata, Redose, delay.off = c(0,0), ncomp = 2, constant = TRUE, control.args = list(), typ = "cw", model = "gok", origin = FALSE, errMethod = "sp", nsim = 500, weight.decomp = FALSE, weight.fitGrowth = TRUE, trial = TRUE, nofit.rgd = NULL, outpdf = NULL, log = "x", lwd = 2, test.dose = NULL, agID = NULL)
Sigdata |
matrix(required): a series of decay curves stored in a matrix column by column, the first column denotes stimulation time values, see details.
Data structure of this kind can be obtained using function pickBINdata by setting argument |
Redose |
vector(required): regenerative dose values. Example: |
delay.off |
vector(with default): a two-elment vector indicating the "Delay" and "Off" |
ncomp |
integer(with default): number of decomposed components |
constant |
logical(with default): logical value indicating if a constant background should be subtracted from the decay curve, see function decomp for details |
control.args |
list(with default): arguments used in the differential evolution algorithm, see function decomp for details |
typ |
character(with default): type of an OSL decay curve, only CW-OSL decay curve can be analyzed currently |
model |
character(with default): model used for growth curve fitting, see function |
origin |
logical(with default): logical value indicating if the growth curve should be forced to pass the origin |
errMethod |
character(with default): method used for equivalent dose error assessment. See function calED for details |
nsim |
integer(with default): desired number of randomly simulated equivalent dose obtained by Monte Carlo simulation |
weight.decomp |
character(with default): logical value indicating if the decay curve should be fitted using a weighted procedure, see function decomp for details |
weight.fitGrowth |
character(with default): logical value indicating if the growth curve should be fitted using a weighted procedure, see function fitGrowth for details |
trial |
logical(with default): logical value indicating if the growth curve should be fitted using other models if the given model fails, see function fitGrowth for details |
nofit.rgd |
integer(optional): regenerative doses that will not be used during the fitting.
For example, if |
outpdf |
character(optional): if specified, results of fast-component equivalent dose calculation will be written to a PDF file
named |
log |
character(with default): a character string which contains "x" if the x axis is to be logarithmic, "y" if the y axis is to be logarithmic and "xy" or "yx" if both axes are to be logarithmic |
lwd |
numeric(with default): width of curves (lines) |
test.dose |
numeric(optional): test dose of decay curves |
agID |
vector(optional): a three-elemenet vector indicating aliquot (grain) ID, i.e., |
Function fastED is used to estimate a fast-component equivalent dose using data sets obtained from the SAR protocol (Murray and Wintle, 2000). The routine trys to decompose a series of decay curves to a specified number of components, then the numbers of trapped electrons from the fast-component will be used to construct the growth curve to estimate a fast-component equivalent dose. See function decomp, fitGrowth, and calED for more details concerning decay curve decomposition, growth curve fitting, and equivalent dose calculation, respectively.
Argument Sigdata
is a column-matrix made up with stimulation time values and a number of decay curves:
Column.no | Description |
I | Stimulation time values |
II | Natural-dose signal values |
III | Test-dose signal values for the natural-dose |
IV | The 1th Regenerative-dose signal values |
V | Test-dose signal values for the 1th regenerative-dose |
VI | The 2th regenerative-dose signal values |
VII | Test-dose signal values for the 2th regenerative-dose |
... | ... |
Return an invisible list containing the following elements:
decomp.pars |
a list containing optimized parameters of successfully fitted decay curves |
Curvedata |
data sets used for building the fast-component growth curve |
Ltx |
sensitivity-corrected natural-dose fast-component signal and its standard error |
LMpars |
optimizaed parameters for the fast-component growth curve |
value |
minimized objective for the fast-component growth curve |
avg.error |
average fit error for the fast-component growth curve |
RCS |
reduced chi-square value for the fast-component growth curve |
FOM |
figure of merit value for the fast-component growth curve in percent |
calED.method |
method used for fast-component equivalent dose calculation, i.e., |
mcED |
randomly simulated fast-component equivalent doses |
ED |
fast-component equivalent dose and its standard error |
ConfInt |
68 percent and 95 percent confidence interval of fast-component equivalent dose |
RecyclingRatio1 |
the first fast-component recycling ratio and its standard error |
RecyclingRatio2 |
the second fast-component recycling ratio and its standard error |
RecyclingRatio3 |
the third fast-component recycling ratio and its standard error |
Recuperation1 |
the first fast-component recuperation (i.e., ratio of the sensitivity-corrected |
Recuperation2 |
the second fast-component recuperation (i.e., ratio of the sensitivity-corrected zero-dose signal to maximum regenerative-dose signal) and its standard error in percent |
Argument test.dose
and agID
have nothing to do with fast-component equivalent dose calculation. They are used only for plotting purpose.
The number of trapped electrons that corresponds to the largest decay rate will be regarded as the fast-component signal, which cannot always ensure that a pure fast-component signal be extracted if an ultra-fast decaying component appears.
The authors thank Professor Sheng-Hua Li and Professor Geoff Duller for their helpful discussions concerning fast-component equivalent dose calculation.
Li SH, Li B, 2006. Dose measurement using the fast component of LM-OSL signals from quartz. Radiation Measurements, 41(5): 534-541.
Murray AS, Wintle AG, 2000. Luminescence dating of quartz using improved single-aliquot regenerative-dose protocol. Radiation Measurements, 32(1): 57-73.
pickBINdata; Signaldata;
fitGrowth; decomp; calED
### Example 1 (not run): # data(Signaldata) # fastED(Signaldata$cw,Redose=c(80,160,240,320,0, 80)*0.13, # ncomp=3, constant=FALSE, outpdf="fastED1") ### Example 2 (not run): # data(BIN) # obj_pickBIN <- pickBINdata(BIN, Position=6, Grain=0, # LType="OSL", force.matrix=TRUE) # fastED(obj_pickBIN$BINdata[[1]], ncomp=2, constant=TRUE, # Redose=c(100,200,300,400,0,100)*0.13, outpdf="fastED2")