nlts (version 0.2-0)

contingency.periodogram: The contingency periodogram for periodicity in categorical time series

Description

A funcion to estimate the contingency periodogram to test for periodicity in categorical time series.

Usage

contingency.periodogram(x, maxper = 6)

Arguments

x

A vector representing the categorical time series.

maxper

the maximum lag (period) considered.

Value

An object of class "contingency.periodogram" is returned consisting of a matrix with a row for each period considered. The columns are:

exact.p

the fischer exact test at each lag.

chi-val

the asymptotic chi-square value.

df

the chi-square degrees-of-freedom.

asympt.p

the chi-squared asymptotic p-value.

Details

This is the contingency periodogram of Pierre Legedre and Pierre Dutielle to test for periodicity in categorical time series. I have coded the function so as to provide both the Fisher exact test and the asymptotic chi-square test.

References

Legendre et al. (1981) The contingency periodogram: A method for identifying rhytms in series of nonmetric ecological data. Journal of Ecology, 69, 965-979.

See Also

plot.contingency.periodogram

Examples

# NOT RUN {
    data(plodia)
    data<-as.factor((scale(plodia) > 0))
    fit <- contingency.periodogram(data, maxper = 9) 
    
# }
# NOT RUN {
plot.contingency.periodogram(fit)
# }