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UTRRNO

       REAL FUNCTION  UTRRNO (JUNK)
 C$    (Normally-Distributed Pseudo-Random Number)
 C$    Return a normally-distributed  pseudo-random number as  the
 C$    function value.
 C$
 C$    The integer argument, JUNK, is a dummy that is ignored.
 C$
 C$    The  numbers produced  have  zero  mean and  unit  standard
 C$    deviation, often denoted N(0,1).  They cluster  around zero
 C$    with rapidly decreasing frequency of occurrence outside the
 C$    the interval  -1.0 .. +1.0.   In a test using 1000000 calls
 C$    to   this  function, 317485  absolute  values exceeded 1.0,
 C$    45751 exceeded 2.0,  2749 exceeded 3.0, 72  exceeded 4.0, 1
 C$    exceeded 5.0, and none were larger than 6.0.
 C$
 C$    To    generate  a    sequence    of normally    distributed
 C$    pseudo-random numbers with  mean  mu and variance sigma**2,
 C$    N(mu,sigma**2), use sigma*UTRRNO(junk) + mu.
 C$
 C$    Before    calling  this  generator,     call  the  function
 C$    UTRRNI(ISEED) once to initialize the sequence.
 C$
 C$    Typical usage:
 C$
 C$    REAL UTRRNI,UTRRNO,Z
 C$    INTEGER ISEED,I
 C$
 C$    ISEED = 305
 C$    Z = UTRRNI(ISEED)
 C$
 C$    DO FOR I = 1,10
 C$       Z = UTRRNO()
 C$       WRITE(*,*) Z
 C$    END FOR
 C$
 C$    This code is essentially that given in the book
 C$
 C$    David Kahaner, Cleve Moler, and Stephen Nash
 C$    Numerical Methods and Software
 C$    Prentice Hall, 1989
 C$    ISBN 0-13-627258-4
 C$
 C$    as the  functions RNOR()  and RSTART().   It was originally
 C$    written   on   15-Sep-1981  by   David  Kahaner and  George
 C$    Marsaglia, and revised  19-Apr-1987.  See also  the article
 C$    by G.  Marsaglia and  ?  Tsang, A  Fast, Easily Implemented
 C$    Method  for Sampling from  Decreasing or Symmetric Unimodal
 C$    Density Functions", SIAM J SISC 1983.
 C$
 C$    (23-Feb-1991)