SUBROUTINE CHIO(N,S2,ANU,NITER,H)
C  This routine draws from N independent chi square distributions, subject
C  to the restriction that the realizations are monotonically nondescending.
C  Inputs:
C  N         Number of distributions
C  S2(Nx1)   Constant parameters for distributions
C  ANU(Nx1)  Degrees of freedom parameters for distributions
C  NITER     Number of Gibbs iterations to perform
C  Input/outputs:
C  H         Random vector
      IMPLICIT REAL*8 (A-H,O-Z)
      DIMENSION S2(N),ANU(N),H(N)
      DIMENSION V1(10)
      V1(1)=CHI(S2(1),ANU(1))
      DO 10 I=2,N
      V1(I)=CHI(S2(I),ANU(I))
   10 IF(V1(I).LE.V1(I-1))RETURN
      CALL DCOPY(N,V1,1,H,1)
      RETURN
      END