sea.sens.slope {trend}

Seasonal Sen's Slope

Description

Computes seasonal Sen's slope for linear rate of change

Usage

sea.sens.slope(x)

Arguments

x

a time series object of class "ts"

Details

Acccording to Hirsch et al. (1982) the seasonal Sen's slope is calculated as follows:

d_{ijk} = \frac{x_{ij} - x_{ik}}{j - k}

for each (x_{ij}, x_{ik}) pair i = 1, \ldots, m, where (1 \leq k < j \leq n_i and n_i is the number of known values in the i-th season. The seasonal slope estimator is the median of the d_{ijk} values.

Value

numeric, Seasonal Sen's slope.

Note

Current Version is for complete observations only.

References

Hipel, K.W. and McLeod, A.I. (1994), Time Series Modelling of Water Resources and Environmental Systems. New York: Elsevier Science.

Hirsch, R., J. Slack, R. Smith (1982), T echniques of Trend Analysis for Monthly Water Quality Data. Water Resources Research 18, 107-121.

Sen, P.K. (1968), Estimates of the regression coefficient based on Kendall's tau, Journal of the American Statistical Association 63, 1379–1389.

See Also

smk.test,

Examples

sea.sens.slope(nottem)