C===================================================== SORT.FOR
      SUBROUTINE SORT(X,N)
C***********************************************************************
C*                                                                     *
C*  FORTRAN CODE WRITTEN FOR INCLUSION IN IBM RESEARCH REPORT RC20525, *
C*  'FORTRAN ROUTINES FOR USE WITH THE METHOD OF L-MOMENTS, VERSION 3' *
C*                                                                     *
C*  J. R. M. HOSKING                                                   *
C*  IBM RESEARCH DIVISION                                              *
C*  T. J. WATSON RESEARCH CENTER                                       *
C*  YORKTOWN HEIGHTS                                                   *
C*  NEW YORK 10598, U.S.A.                                             *
C*                                                                     *
C*  VERSION 3     AUGUST 1996                                          *
C*                                                                     *
C***********************************************************************
C
C  SORTS THE ARRAY X INTO ASCENDING ORDER
C
C  PARAMETERS OF ROUTINE:
C  X      *IN/OUT* ARRAY OF LENGTH N. CONTAINS THE NUMBERS TO BE SORTED.
C                  ON EXIT, CONTAINS THE SORTED NUMBERS.
C  N      * INPUT* NUMBER OF ELEMENTS TO BE SORTED
C
C  METHOD USED IS SHELL SORT WITH SEQUENCE OF INCREMENTS AS IN
C  D.F.KNUTH (1969) 'THE ART OF COMPUTER PROGRAMMING', VOL.3, P.95
C
      IMPLICIT DOUBLE PRECISION (A-H,O-Z)
      DOUBLE PRECISION X(N)
      IF(N.LE.1)RETURN
      J=4
      DO 10 I=1,100
      J=3*J+1
      IF(J.GE.N)GOTO 20
   10 CONTINUE
   20 CONTINUE
      M=(J/3)
      DO 60 MM=1,100
      M=M/3
      IF(M.EQ.0)RETURN
      DO 50 I=M+1,N
      TEST=X(I)
      J=I
      DO 30 JJ=1,100
      J=J-M
      IF(J.LE.0)GOTO 40
      IF(TEST.GE.X(J))GOTO 40
   30 X(J+M)=X(J)
   40 CONTINUE
   50 X(J+M)=TEST
   60 CONTINUE
      END