mixparam.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 June 2002

mixparam <- function(mu, sigma, pi = NULL) 
{
    k <- length(mu)
    if (is.null(pi)) 
        pi <- rep(1/k, k)
    if (length(sigma) == 1) 
        sigma <- rep(sigma, k)
    else if (length(sigma) > k) {
        warning(paste("The length of sigma is greater than that of mu, the first ", 
            k, " sigmas was used", sep = ""))
        sigma <- sigma[1:k]
    }
    else if (length(sigma) < k) {
        warning("The length of sigma is less than that of mu, the first sigma was used")
        sigma <- rep(sigma[1], k)
    }
    if (k > 1) {
        if (sum(mu[-k] - mu[-1] > 0) > 0) 
            stop("Means must be in ascending order.")
        if (sum(mu[-k] - mu[-1] == 0 & sigma[-k] - sigma[-1] == 
            0) > 0) 
            stop("Sigmas must be in ascending order when means are equal.")
    }
    data.frame(pi = pi, mu = mu, sigma = sigma)
}