R: Build Mean Value Chronology

chron {dplR} | R Documentation

## Build Mean Value Chronology

### Description

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

### Usage

    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

    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)

[Package dplR version 1.7.1 Index]