

   TThhee IInnvveerrssee GGaauussssiiaann DDiissttrriibbuuttiioonn

        dinvgauss(y, m, s)
        pinvgauss(q, m, s)
        hinvgauss(y m, s)

   AArrgguummeennttss::

          y: vector of responses.

          q: vector of quantiles.

          m: vector of means.

          s: vector of dispersion parameters.

   DDeessccrriippttiioonn::

        These functions provide information about the inverse
        Gaussian distribution with mean equal to `m' and dis-
        persion equal to `s'.  `dinvgauss' gives the density,
        `pinvgauss' gives the distribution function, `hin-
        vgauss' gives the hazard function.

        The inverse Gaussian distribution has density

        f(y) = 1/sqrt(2 pi s y^3) e^-((y - m)^2/(2 y s^2 m^2))

        where m is the mean of the distribution and s is the
        dispersion.

   AAuutthhoorr((ss))::

        J.K. Lindsey

   SSeeee AAllssoo::

        `dnorm' for the normal distribution and `dlnorm' for
        the Lognormal distribution.

   EExxaammpplleess::

        dinvgauss(5, 5, 1)
        pinvgauss(5, 5, 1)

