Computes the logratio mean composition of a continuous mixture of point-counting data.
# S3 method for counts
central(x, ...)an [5 x n] matrix with n being the number
of categories and the rows containing:
the `central' composition.
the standard error for the central composition.
the overdispersion parameter, i.e. the coefficient of
variation of the underlying logistic normal
distribution. central computes a continuous
mixture model for each component (column)
separately. Covariance terms are not reported.
the lower limit of a `1 sigma' region for theta.
the upper limit of a `1 sigma' region for theta.
the mean square of the weighted deviates, a.k.a. reduced chi-square statistic.
the p-value for age homogeneity
an object of class counts
optional arguments
The central composition assumes that the observed point-counting distribution is the combination of two sources of scatter: counting uncertainty and true geological dispersion.