chron: Build Mean Value Chronology

Description Usage Arguments Details Value Author(s) References See Also Examples

Description

This function builds a mean value chronology, typically from a data.frame of detrended ring widths as produced by detrend.

Usage

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chron(x, prefix = "xxx", biweight = TRUE, prewhiten = FALSE, ...)

Arguments

x

a data.frame of ring widths with rownames(x) containing years and colnames(x) containing each series ID such as produced by read.rwl

prefix

a character string with less than 4 characters. Defaults to "xxx"

biweight

logical flag. If TRUE then a robust mean is calculated using tbrm.

prewhiten

logical flag. If TRUE each series is whitened using ar prior to averaging.

...

Arguments passed to ar when prewhiten is TRUE. For example, use aic and order.max to control the order of the AR model.

Details

This either averages the rows of the data.frame using a mean or a robust mean (the so-called standard chronology) or can do so from the residuals of an AR process (the residual chronology).

Value

A data.frame with the standard chronology, residual chronology (if prewhitening was performed), and the sample depth.

Author(s)

Andy Bunn. Patched and improved by Mikko Korpela.

References

Cook, E. R. and Kairiukstis, L. A., editors (1990) Methods of Dendrochronology: Applications in the Environmental Sciences. Springer. ISBN-13: 978-0-7923-0586-6.

Fritts, H. C. (2001) Tree Rings and Climate. Blackburn. ISBN-13: 978-1-930665-39-2.

See Also

read.rwl, detrend, ar, crn.plot

Examples

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library(graphics)
library(utils)
data(ca533)
ca533.rwi <- detrend(rwl = ca533, method = "ModNegExp")
ca533.crn <- chron(ca533.rwi, prefix = "CAM")
plot(ca533.crn,xlab="Year",ylab="RWI")
## With residual chron
ca533.crn <- chron(ca533.rwi, prefix = "CAM", prewhiten = TRUE)

dplR documentation built on Nov. 4, 2018, 3 a.m.