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)
x | A vector time series with frequency > 1 |
---|
"Trend" chi-square.
"Homogeneous" chi-square.
For null hypothesis that trends are homogeneous.
Number of seasons used.
van Belle, G. and Hughes, J.P. (1984) Nonparametric tests for trend in water quality. Water Resources Research 20, 127-136.
Alan Jassby, James Cloern
## 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 #>