

   TThhee LLoogg NNoorrmmaall DDiissttrriibbuuttiioonn

        dlnorm(x, meanlog = 0, sdlog = 1)
        plnorm(q, meanlog = 0, sdlog = 1)
        qlnorm(p, meanlog = 0, sdlog = 1)
        rlnorm(n, meanlog = 0, sdlog = 1)

   AArrgguummeennttss::

        x,q: vector of quantiles.

          p: vector of probabilities.

          n: number of observations to generate.

   meanlog,sdlog: mean and standard deviation of the distribu-
             tion on the log scale

   DDeessccrriippttiioonn::

        These functions provide information about the log nor-
        mal distribution whose logarithm has mean equal to
        `meanlog' and standard deviation equal to `sdlog'.
        `dlnorm' gives the density, `plnorm' gives the distri-
        bution function `qlnorm' gives the quantile function
        and `rlnorm' generates random deviates.

        If `meanlog' or `sdlog' are not specified they assume
        the default values of `0' and `1' respectively.

        The log normal distribution has density

        f(x) = 1/(sqrt(2 pi) sigma x) e^-((log x - mu)^2 / (2 sigma^2))

        where mu and sigma are the mean and standard deviation
        of the logarithm.

   SSeeee AAllssoo::

        `dnorm' for the normal distribution.

   EExxaammpplleess::

        dlnorm(1) == dnorm(0)
        x <- rlnorm(1000)   # not yet always :
        all(abs(x  -  qlnorm(plnorm(x))) < 1e4 * .Machine$double.eps * x)

