| acidity {multimode} | R Documentation |
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.
Source
Obtained from the Supplementary material of Richardson and Green (1997), available in http://www.stats.bris.ac.uk/~peter/mixdata.
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
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)")