fitmixEM: Fits lifespan data of time units with gompertz,...
In fitmix: Finite Mixture Model Fitting of Lifespan Datasets

Description Usage Arguments Details Value References Examples

View source: R/fitmixEM.R

Fits lifespan data of time units with gompertz, log-logistics, log-normal, and weibull mixture models choice of one.

1	fitmixEM(lifespan, model, K, initial = FALSE, starts)

`lifespan`	numeric vector of lifespan dataset
`model`	model name of the one of the well-known model: `gompertz`,`log-logistics`,`log-normal`, and `weibull`.
`K`	number of well-known model components.
`initial`	logical true or false
`starts`	numeric if initial sets to true

Estimates parameters of the given mixture model implementing the expectation maximization (EM) algorithm. General form for the cdf of a statistical mixture model is given by a distribution f is a mixture of K component distributions of f = (f_1, f_2,..f_K) if

f(x) = ∑_{k=1}^{K}λ_k f_k(x)

with λ_k > 0, ∑_k λ_k = 1. This equation is a stochastic model, thus it allows to generate new data points; first picks a distribution of choice, with probablities by weight, then generates another observation according to the chosen distribution. In short represenated by, Z ~ Mult(λ_1, λ_2,...λ_k) and X|Z ~ f_Z, where Z is a discrete random variable which component X is drawn from.

The families considered for the cdf of Gompertz, Log-normal, Log-logistic, and Weibull.

1.The return has three values; the first value is estimate, measures, and cluster.

2. The second value includes four different measurements of goodness-of-fit tests involving: Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC), Kolmogorov-Smirnov (KS), and log-likelihood (log.likelihood) statistics.

3. The last value is the output of clustering vector.

Farewell, V. (1982). The Use of Mixture Models for the Analysis of Survival Data with Long-Term Survivors. Biometrics, 38(4), 1041-1046. doi:10.2307/2529885 McLachlan, G. J. and Peel, D. (2000) Finite Mixture Models, John Wiley \& Sons, Inc.

Essam K. Al-Hussaini, Gannat R. Al-Dayian & Samia A. Adham (2000) On finite mixture of two-component gompertz lifetime model, Journal of Statistical Computation and Simulation, 67:1, 20-67, DOI: 10.1080/00949650008812033