| mannkendall.stat {emon} | R Documentation |
Mann-Kendall statistic.
Description
Calculates the Mann-Kendall statistic for monotonic trend. Unlike the function MannKendall, works
for repeat values of time. Used in function mannkendall, which also calculates the p-value by simulation.
Usage
mannkendall.stat(time, Y) Arguments
time |
Vector of values which define the direction of the trend. |
Y |
Vector of values for which you want to determine the trend. |
Details
The statistic is calculated by considering
each case j and considering the subset of observations that have time greater than time[j]. The Mann Kendall
statistic is the number of observations in this subset for which Y > Y[j] minus the number for
which Y < Y[j].
The statistic is summed over all j. The p-value is calculated by nreps random permutations of the Y values.
Value
Mann-Kendall statistic
Author(s)
Jon Barry: Jon.Barry@cefas.co.uk
References
Mann, H.B. (1945), Nonparametric tests against trend, Econometrica, 13, 245-259. Kendall, M.G. 1975. Rank Correlation Methods, 4th edition, Charles Griffin, London.
See Also
mannkendall, power.trend, MannKendall