This function calculates the matrix of
Gleichläufigkeit{Gleichlaeufigkeit} for a given set of tree-ring
records.
Usage
glk(x)
Arguments
x
a data.frame of tree-ring data with records in
columns, and years as rows.
Value
A matrix with the Gleichläufigkeit{Gleichlaeufigkeit} for
all possible combinations of records. If two curves have less than 3
years of overlap, Gleichläufigkeit{Gleichlaeufigkeit} cannot be
computed, and NA is returned.
Details
Gleichläufigkeit{Gleichlaeufigkeit} is a classical agreement
test based on sign tests (Eckstein and Bauch, 1969). This function
implements Gleichläufigkeit{Gleichlaeufigkeit} as the pairwise
comparison of all records in data set, and thus returns a matrix whose
upper triangle reports the Gleichläufigkeit{Gleichlaeufigkeit}
of each possible combination of records. The global
Gleichläufigkeit{Gleichlaeufigkeit} can be calculated as
mean(glk(x), na.rm = TRUE).
References
Eckstein, D., Bauch J. (1969) Beitrag zur Rationalisierung eines
dendrochronologischen Verfahrens und zur Analyse seiner
Aussagesicherheit. Forstwissenschaftliches Centralblatt,
88(1):230–{--}250.
Schweingruber, F. H. (1988) Tree rings: basics and applications
of dendrochronology. Kluwer Academic Publishers, Dordrecht,
Netherlands, 276 p.