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@node Ranlib, , Top, Top
@section Ranlib

The ranlib libary from University of Texas contains  a large number of
random number generators.


@table @kbd

@item Beta distribution.
@code{@@betarand(@var{a},@var{b})}
generates  a single random deviate from the beta distribution with
parameters @var{a} and @var{b}.  The density of the beta distribution is
@example

               x^(a-1) * (1-x)^(b-1) / B(a,b) for 0 < x < 1
@end example

@item Chi Squared Distribution
@code{@@chirand(@var{df})} generates a random deviate from a chisquare
distribution with @var{df} degrees of freedom. @var{df} must be
positive.

@item  Exponential Distribution
@code{@@exprand(@var{av})}
     generates a single random deviate from an exponential
     distribution with mean @var{av}.

@item F distribution
@code{@@fdist(@var{dfn},@var{dfd})} 
generates a random deviate from the F
distribution with @var{dfn} degrees of freedom in the numerator
and @var{dfd} degrees of freedom in the denominator.  Both arguments
must be positive.

@item Gamma distribution
@code{@@gammarand(@var{a},@var{r})}
generates random deviates from the gamma distribution whose
density is 
@example

          (a**r)/gamma(r) * x**(r-1) * exp(-a*x)
@end example
where @var{a} is the  location parameter of Gamma distribution
and @var{r} is the  shape parameter of Gamma distribution.


@item Non Central Chi Square Distribution
@code{@@nchirand(@var{df},@var{xnonc})}
     generates random deviate  from the  distribution  of a  noncentral
     chisquare with @var{df} degrees  of freedom and noncentrality  parameter
     @var{xnonc}. @var{df} must be greater than 1, and @var{xnonc} must
     be positive.


@item Non Central F distribution
@code{@@nfrand(@var{dfn},@var{dfd},@var{xnonc})}
     generates a random deviate from the  noncentral F 
     distribution with @var{dfn} degrees of freedom in the numerator,
     @var{dfd}      degrees of freedom in the denominator, and
     noncentrality parameter @var{xnonc}.
     @var{dfn} must be at least 1, @var{dfd} must be positive, and
     @var{xnonc} must be non-negative.

@item Normal Distribution
@code{@@normalrand(@var{mu},@var{sd})}
     generates a single random deviate from a normal distribution with
     mean @var{mu}, and standard deviation, @var{sd}.

@item Uniform Distribution
@code{@@unirand(@var{low},@var{high})}
     generates a real uniformly distributed between @var{low} and @var{high}.


@item Binomial Distribution 
@code{@@binomialrand(@var{n},@var{p})}         generates a single random
deviate from a binomial       distribution with @var{n} trials, and 
the  probability of an event in each trial is @var{p}.
The result is a random deviate yielding the number of events
from @var{n} independent trials, each of which has  a probability of
event @var{p}. 

@item  Poisson Distribution
@code{@@poisonrand(@var{mu})}
     generates a single random deviate from a Poisson
     distribution with mean @var{mu}.


@item Uniform Integers
@code{@@intunirand(@var{low},@var{high})}
generates an integer uniformly distributed between @var{low} and @var{high}.


@end table

