IsoplotR (version 0.6)

agespectrum: Plot a ($^{40}$Ar/$^{39}$Ar) release spectrum

Description

Produces a plot of boxes whose widths correspond to the cumulative amount of $^{39}$Ar (or any other volume proxy), and whose heights express the analytical uncertainties.

Usage

agespectrum(x, ...)
"agespectrum"(x, alpha = 0.05, plateau = TRUE, plateau.col = rgb(0, 1, 0, 0.5), non.plateau.col = rgb(0, 1, 1, 0.5), sigdig = 2, line.col = "red", lwd = 2, title = TRUE, ...)
"agespectrum"(x, alpha = 0.05, plateau = TRUE, plateau.col = rgb(0, 1, 0, 0.5), non.plateau.col = rgb(0, 1, 1, 0.5), sigdig = 2, dcu = TRUE, line.col = "red", lwd = 2, ...)

Arguments

x

a three column matrix whose first column gives the amount of $^{39}$Ar in each aliquot, and whose second and third columns give the age and its uncertainty.

OR

an object of class ArAr with format=2

...

optional parameters to the generic plot function

alpha

the confidence limits of the error bars/boxes.

plateau

Boolean flag indicating whether a plateau age should be calculated if plateau=TRUE, the function will compute the weighted mean of the largest succession of steps that yield values passing the Chi-square test for age homogeneity.

plateau.col

the fill colour of the rectangles used to mark the steps belonging to the age plateau.

non.plateau.col

if plateau=TRUE, the steps that do NOT belong to the plateau are given a different colour.

sigdig

the number of significant digits of the numerical values reported in the title of the graphical output (only used if plateau=FALSE).

line.col

colour of the isochron line

lwd

line width

title

add a title to the plot? If FALSE, returns a list with plateau parameters.

dcu

propagate the decay constant uncertainties?

Value

if title=FALSE, a list with the following items:mean a 2-element vector with the plateau mean and standard errormswd the mean square of the weighted deviates of the plateaup.value the p-value of a Chi-square test with n-1 degrees of freedom, where n is the number of steps in the plateau.nfract the fraction of $^{39}Ar$ contained in the plateau

Examples

data(examples)
agespectrum(examples$ArAr)