The function wawotest.default performs a Wald Wolfowitz test of
the random distribution of the values in a vector. The function
wawotest.ltraj performs this tests for the descriptive
parameters dx, dy and dist in an object of class
ltraj. The function wawotest is generic.
wawotest(x, ...)
# S3 method for default
wawotest(x, alter = c("greater", "less"), ...)
# S3 method for ltraj
wawotest(x, ...)wawotest.default returns a vector containing the value of the
statistic (a), its esperance (ea), its variance
(va), the normed statistic (za) and the
P-value. wawotest.ltraj returns a table giving these values for
the descriptive parameters of the trajectory.
for wawotest.default, a vector containing the
successive observations building the series.
For wawotest.ltraj, an object of class ltraj.
a character string specifying the alternative hypothesis, must be one of "greater" (default), "less" or "two-sided"
additional arguments to be passed to other functions
Stephane Dray dray@biomserv.univ-lyon1.fr
The statistic of the test is equal to A = sum(y(i) y(i+1)), with y(N+1) = y(1). Under the hypothesis of a random distribution of the values in the vector, this statistic is normally distributed, with theoretical means and variances given in Wald & Wolfowitz (1943).
Wald, A. & Wolfowitz, J. (1943) An exact test for randomness in the non-parametric case based on serial correlation. Ann. Math. Statist., 14, 378--388.
indmove and runsNAltraj for other
tests of independence to be used with objects of class "ltraj"
data(puechcirc)
puechcirc
wawotest(puechcirc)
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