

   TThhee ppoowweerr eexxppoonneennttiiaall DDiissttrriibbuuttiioonn

        dpowexp(y, m=0, s=1, f=1)
        ppowexp(q, m=0, s=1, f=1)

   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.

          f: vector of family parameters.

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

        These functions provide information about the power
        exponential distribution with mean parameter equal to
        `m', dispersion equal to `s', and family parameter
        equal to `f'.  `dpowexp' gives the density, `ppowexp'
        gives the distribution function.

        The power exponential distribution has density

               f(y) = exp(-(abs(y-m)/sqrt(s))^(2 f)/2)/
               (sqrt(s) Gamma(1+1/(2 f)) 2^(1+1/(2 f)))

        where m is the mean of the distribution, s is the dis-
        persion, and f is the family parameter. f=1 yields a
        normal distribution, f=0.5 a Laplace distribution, and
        f=Inf  a uniform distribution.

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

        J.K. Lindsey

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

        dpowexp(5, 5, 1, 2)
        ppowexp(5, 5, 1, 2)

