Computes general statistics on ring-width series.

Share:

Description

This function computes general statistics on a data.frame of ring-width series. This function is a changed version of the Andrew Bunn's rwi.stats function from the dplR package (Bunn, 2008)

Usage

1
EPS.value(rwl, stc = c(5,2,1))

Arguments

rwl

a data.frame of ring widths

stc

a vector of three integers giving the Site-Tree-Core mask. Defaults to c(5,2,1) and these three values should sum to eigth. The stc[1] gives the number of characters used to define the site code, stc[2] defines the tree mask and the core ids is given by the last element of the vector stc[3].

Value

A data.frame with the following values: 'start', 'end', 'tree', 'core', 'n.tot', 'n.wt', 'n.bt','r.tot','r.wt', 'r.bt', 'c.eff', 'r.eff', and 'eps'.

start

the first year.

end

the last year.

tree

the number of trees.

core

the number of cores.

n.tot

the number of unique combinations of the input series (i.e., 1/2*n*[n-1]).

n.wt

the total number of unique combinations of the within-tree series.

n.bt

the total number of unique combinations of the between-tree series.

r.tot

the mean of all correlation between different cores.

r.wt

the mean of correlations between series from the same tree over all trees.

r.bt

the mean interseries correlation between all series from different trees.

c.eff

the effective number of cores.

r.eff

the effective signal calculated as [rbar.bt / (rbar.wt + (1-rbar.wt) / c.eff)].

eps

the expressed population signal.

References

Bunn, A. 2008. A dendrochronology program library in R (dplR). Dendrochronologia 26:115-124.

Cook, E.R., Kairiukstis, L.A. 1990. Methods of Dendrochronology: applications in the environmental sciences. Kluwer Academic Publishers.

Examples

1
2
3
4
5
6
7
data(co021, package="dplR")

years<-as.integer(rownames(co021))
co021.subset<-(subset(co021, subset=years>=1900 & years<=1950))
co021.subset<-co021.subset[,-c(28,30,31)] ## to remove the following series "645232","646107" and "646118"

EPS.value(co021.subset, stc=c(0,8,0))