EV1RAN
      SUBROUTINE EV1RAN(N,ISTART,X)
  
PURPOSE--This subroutine generates a random sample of size N
         from the extreme value type 1 distribution.  The
         prototype extreme value type 1 distribution used herein
         has MEAN = EULER'S NUMBER = 0.57721566 and
         STANDARD DEVIATION = PI/SQRT(6) = 1.28254983.  This
         distribution is defined for all X and has the probability
         dendity function(X) = (EXP(-X)) * (EXP(-(EXP(-X))))
INPUT  ARGUMENTS--N      = The desired integer number of random
                           numbers to be generated.
                --ISTART = An integer flag code which (if set to
                           0) will start the generator over and
                           hence produce the same random sample
                           over and over again upon successive
                           calls to this subroutine within a
                           run; or (if set to some integer value
                           not equal to 0, like, say, 1) will
                           allow the generator to continue from
                           where it stopped and hence produce
                           different random samples upon
                           successive calls to this subroutine
                           within a run.
OUTPUT ARGUMENTS--X      = A single precision vector (of
                           dimension at least N) into which
                           the generated random sample will
                           be placed.
OUTPUT--A random sample of size N from the extreme value type
        distribution with MEAN = EULER'S NUMBER = 0.57721566
        and STANDARD DEVIATION = PI/SQRT(6) = 1.28254983.
PRINTING--None unless an input argument error condition exists.
RESTRICTIONS--There is no restriction on the maximum value of N
              for this subroutine.
OTHER DATAPAC   SUBROUTINES NEEDED--UNIRAN.
FORTRAN LIBRARY SUBROUTINES NEEDED--ALOG.
MODE OF INTERNAL OPERATIONS--Single precision.
LANGUAGE--ANSI FORTRAN.
REFERENCES--Tocher, The Art of Simulation, 1963, Pages 14-15.
          --Hammersley and Handcomb Monte Carlo Methods,
            1964, Page 36.
          --Johnson and Kotz, Continuous Univariate
            Distributions--1, 1970, Pages 272-295.
WRITTEN BY--James J. Filliben
            Statistical Engineering Laboratory (205.03)
            National Bureau of Standards
            Gaithersburg, MD  20899
            Phone--  301-921-2315
ORIGINAL VERSION--November  1975.