Trend homogeneity test

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

seaKen

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
#>