R/dlnormMix.R

In EnvStats: Package for Environmental Statistics, Including US EPA Guidance

dlnormMix <-
function (x, meanlog1 = 0, sdlog1 = 1, meanlog2 = 0, sdlog2 = 1,
    p.mix = 0.5)
{
    names.x <- names(x)
    arg.mat <- cbind.no.warn(x = as.vector(x), meanlog1 = as.vector(meanlog1),
        sdlog1 = as.vector(sdlog1), meanlog2 = as.vector(meanlog2),
        sdlog2 = as.vector(sdlog2), p.mix = as.vector(p.mix))
    for (i in c("x", "meanlog1", "sdlog1", "meanlog2", "sdlog2",
        "p.mix")) assign(i, arg.mat[, i])
    na.index <- is_na_matrix(arg.mat)
    if (all(na.index))
        y <- rep(NA, length(x))
    else {
        if (any(c(sdlog1[!na.index], sdlog2[!na.index]) < .Machine$double.eps))
            stop("All values of 'sdlog1' and 'sdlog2' must be positive.")
        if (any(p.mix[!na.index] < 0 | p.mix[!na.index] > 1))
            stop("All values of 'p.mix' must be between 0 and 1")
        y <- (1 - p.mix) * dlnorm(x, meanlog1, sdlog1) + p.mix *
            dlnorm(x, meanlog2, sdlog2)
    }
    if (!is.null(names.x))
        names(y) <- rep(names.x, length = length(y))
    else names(y) <- NULL
    y
}