multimode (version 1.4)

acidity: Acid--neutralizing capacity

Description

This dataset, analyzed by Crawford (1994), contains the Acid--Neutralizing Capacity (ANC) measured in a sample of 155 lakes in North--Central Wisconsin (USA). ANC describes the capability of a lake to absorb acid, where low ANC values may lead to a loss of biological resources.

Usage

data(acidity)

Format

acidity includes an acidity index of lakes in north--central Wisconsin on the log scale, in particular, it is provided the log(ANC+50) as in Crawford (1994).

Details

This is a classic example for determining the number of modes.

References

Crawford (1994). An application of the Laplace method to finite mixture distributions. Journal of the American Statistical Association, 89, 259--267.

Richardson, S. and Green, P. J. (1997). On Bayesian analysis of mixtures with unknown number of components (with discussion). Journal of the Royal Statistical Society, Series B, 59, 731--792.

Examples

# NOT RUN {
data("acidity")
# Kernel density estimation with two modes and SiZer
locmodes(acidity,mod0=2,display=TRUE,xlab="log(ANC+50)")
sizer(acidity,bws=c(0.1,1),xlab="log(ANC+50)")
# }