Tests for homogeneity of seasonal trends using method proposed by van Belle and Hughes (1984). Seasons with insufficient data as defined in mannKen are ignored.

trendHomog(x)

Arguments

x

A vector time series with frequency > 1

Value

chisq.trend

"Trend" chi-square.

chisq.homog

"Homogeneous" chi-square.

p.value

For null hypothesis that trends are homogeneous.

n

Number of seasons used.

References

van Belle, G. and Hughes, J.P. (1984) Nonparametric tests for trend in water quality. Water Resources Research 20, 127-136.

See also

Author

Alan Jassby, James Cloern

Examples

## Apply to a monthly vector time series to test homogeneity ## of seasonal trends. x <- sfbayChla[, 's27'] trendHomog(x)
#> $chi2.trend #> [1] 106.3295 #> #> $chi2.homog #> [1] 10.17219 #> #> $p.value #> [1] 0.4255185 #> #> $n #> [1] 11 #>