C
C     COMDECK: COMMIN
C
C     Parameters associated with the control variable of the
C     variational analysis
C
C     NI,NJ,NK: dimension of model/analysis grid
C     NVADIM  : dimension of the control vector
C     NDATA   : number of data values (observations)
C     NVAMAJ  : number of updates of the Hessian matrix to be considered
C     .         by the quasi-Newton algorithm
C     NMTRA   : workspace needed by the minimization module
C     NIMPRES : parameter controlling the impression of the minimization
C     .         module (see MODULOPT documentation)
C     NITERMAX: max. number of iterations  (see MODULOPT documentation)
C     NSIMMAX : max. number of simulations (see MODULOPT documentation)
C     REPSG   : precision of the stopping criterion (see MODULOPT documentation)
C     NGRTEST : used to trigger the gradient test (=1)
C     NGRANGE : range used for the gradient test
C     ------------
C     NEVALJ  : = 1 contribution of Jg and Jo are both considered
C     .         = 2 only Jg is considered
C     .         = 3 only Jo is considered
C     VAZX(NVADIM)    : control variable used by the minimization
C     VAZG(NVADIM)    : gradient of the functional
C     VATRA(NMTRA)    : workspace used by the minimization subroutine
C     XMOD(NI,NJ)     : model state (increment and workspace)
C     TRIAL(NI,NJ)    : trial field
C     INNOV(NDATA)    : innovation vector
C     OBS(NDATA)      : observations (data)
C     NULOUT          : unit number for listing file
C
      INTEGER NMTRA,NVAMAJ,NIMPRES,NITERMAX,NSIMMAX
     &       ,NEVALJ,NNEVALJ,NGRTEST,NGRANGE,NULOUT,NI,NJ,NK,
     &        NDATA,NVADIM
      REAL*8 REPSG,RPRECIS
C
C     Parameters related to trial field
C
      parameter(NI         = 760)
      parameter(NJ         = 1120)
      parameter(NK         = 63)
      parameter(NVADIM     = NI*NJ*NK)
C
C     Parameters related to data
C
c      parameter(NDATA      = NI*NJ)
C
C     Parameters related to minimization
C
      parameter(REPSG      = 0.001)        ! relative reduction in norm of
                                          ! gradient required for convergence
      parameter(RPRECIS    = 1.D-12)      ! precision of machine
      parameter(NITERMAX   = 20)
      parameter(NSIMMAX    = 20)
      parameter(NVAMAJ     = 6)
      parameter(NGRTEST    = 1)
      parameter(NGRANGE    = 10)
      parameter(NNEVALJ    = 1)
      parameter(NIMPRES    = 5)
      parameter(NULOUT     = 6)
      parameter(NMTRA      = 4*NVADIM+NVAMAJ*(2*NVADIM+1))
C
C     Arrays
C
      REAL*8 VAZX(NVADIM),VAZG(NVADIM),VATRA(NMTRA)
      REAL*8 XMOD(NI,NJ,NK),TRIAL(NI,NJ,NK)
      REAL*8 BSQRT(NK,NK)
      REAL*8, POINTER :: OBS(:), INNOV(:), SIGOBS(:)
      REAL, POINTER :: OBSLON(:), OBSLAT(:)
      INTEGER, POINTER :: IOBS(:),JOBS(:),KOBS(:)
C
      COMMON /commin/VAZX,VAZG,VATRA,NDATA,
     +               XMOD,TRIAL,OBS,INNOV,BSQRT,SIGOBS,IOBS,JOBS,KOBS,
     +               NEVALJ, OBSLON, OBSLAT