coef.mix.r

这个包里面含有利用极大似然估计方法来拟合成组数据和条件数据的有限混合分布模型的函数

## last modified May 2008

coef.mix <- function(object, natpar = FALSE, ...) 
{
    mixobj<-object
    par <- mixobj$parameters
    dist <- mixobj$distribution
    constr <- mixobj$constraint
    mu <- par[, 2]
    sigma <- par[, 3]
    if (!natpar) 
        coef <- par
    else {
        if (dist == "norm") 
            coef <- par
        else if (dist == "lnorm") {
            scale <- sqrt(log((sigma/mu)^2 + 1))
            shape <- log(mu) - (scale^2)/2
            coef <- cbind(par, shape, scale)
        }
        else if (dist == "gamma") {
            shape <- (mu/sigma)^2
            rate <- mu/(sigma^2)
            coef <- cbind(par, shape, rate)
        }
        else if (dist == "weibull") {
            weibpar <- weibullpar(mu, sigma)
            shape <- weibpar$shape
            scale <- weibpar$scale
            coef <- cbind(par, shape, scale)
        }
        else if (dist == "binom") {
            size <- constr$size
            prob <- mu/constr$size
            coef <- cbind(par, size, prob)
        }
        else if (dist == "nbinom") {
            if (constr$consigma == "NBINOM") 
                size <- constr$size
            else size <- mu^2/(sigma^2 - mu)
            prob <- size/(size + mu)
            coef <- cbind(par, size, prob)
        }
        else if (dist == "pois") {
            lambda <- mu
            coef <- cbind(par, lambda)
        }
    }
    coef
}