acidity: Acidity Dataset

In mixComp: Estimation of Order of Mixture Distributions

Description

Data for the Acidity index on the log-scale for 155 lakes in North-Central Wisconsin from the Eastern Lake Survey. The measurements are acid neutralizing capacity (ANC) on the log scale; specifically, log(ANC + 50). The Acidity index describes the capability of a lake to absorb acid; low ANC values can lead to a loss of biological resources, see Crawford (1994).

Usage

data(acidity)

Format

A data frame with 155 observations on 1 variable.

Source

Crawford et al. (1992) Modeling Lake-Chemistry Distributions: Approximate Bayesian Methods for Estimating a Finite-Mixture Model, Technometrics, 34:4, 441-453

Examples

data(acidity)

acidity.obs <- unlist(acidity)

# define the MLE functions for the mean and sd: 
MLE.norm.mean <- function(dat) mean(dat)
MLE.norm.sd <- function(dat){
  sqrt((length(dat) - 1) / length(dat)) * sd(dat)
} 
MLE.norm.list <- list("MLE.norm.mean" = MLE.norm.mean, "MLE.norm.sd" = MLE.norm.sd)

# define the range for parameter values:
norm.bound.list <- list("mean" = c(-Inf, Inf), "sd" = c(0, Inf))

# create 'datMix' object:
acidity.dM <- datMix(acidity.obs, dist = "norm", discrete = FALSE, 
                     MLE.function = MLE.norm.list, 
                     theta.bound.list = norm.bound.list)
                     
                      
set.seed(0)
res <- mix.lrt(acidity.dM, B = 50, quantile = 0.95)
plot(res)

mixComp documentation built on Feb. 25, 2021, 5:07 p.m.