PROGRAM COST_FILT_STEP
! **********************************************************************
! *              .      .    .
! * PROGRAM:    COST_FILT_STEP
! * PRGMMR:     M. ZUPANSKI     ORG: CIRA/CSU   DATE: 2001-04-25
! *
! * ABSTRACT:   THIS PROGRAM PERFORMS THE GRAVITY WAVE PENALTY CALCUL 
! *             BASED ON DIABATIC DIGITAL FILTER (HUANG AND LYNCH, 1997)
! *             STEP-LENGTH RELATED SUMS (ETOP EBOT)
! * 
! * PROGRAM LOG:
! * 
! * 04/25/2001    ..... M. ZUPANSKI:
! * 05/22/2002    ..... M. ZUPANSKI: ensemble DA upgrade
! *
! **********************************************************************
       INCLUDE 'ntype.h'              !!! NTYPE= No. of cntrl vrbl types
       INCLUDE 'mpif.h'
!-----------------------------------------------------------------------
       INCLUDE 'CNTRL4D.comm'
!-----------------------------------------------------------------------
      REAL,DIMENSION(:,:,:),ALLOCATABLE	:: CGBL,CXGBL
!---
      CHARACTER*30 			OLDNAME,TRYNAME
      INTEGER                           IOLD,ITRY

      INCLUDE 'namelist.h'           !!! define namelists (all)


!--- read input files 'cntrl_index.name' (33) and 'cntrl_specs.name' (34)

      INCLUDE 'read_namelist'      ! read all namelists

!-----------------------------------------------------------------------
!***  
!***  INITIALIZE ALL QUANTITIES ASSOCIATED WITH GRID DECOMPOSITION
!***

!-- define model grid -------------

      imeta=IM
      jmeta=JM
!=================================================================
      WRITE(*,*) "       "
      WRITE(*,5055)
      WRITE(3,*) "       "
      WRITE(3,5055)
 5055 FORMAT('START STEP_FILT '/)

!---      READ CONTROL PARAMETERS

      CALL   INITCTRL

!========PENALTY STEP CALCULATION (DIGITAL FILTER)==============
!====================================================================
        EPSTOP=0.0
        EPSBOT=0.0

!---    read input vector C= old g.w. increment 
!---    read input vector CX= trial (updated)  g.w. increment 

!====
        IF(EPSL1.GT.0.0)  THEN 
!====
      ALLOCATE(CGBL(imeta,jmeta,NLEV))
      WRITE(OLDNAME,110) 
 110  FORMAT('oldfilt_incr')
      IOLD=21
      CLOSE(IOLD)
      OPEN(IOLD,file=OLDNAME,status='unknown',form='unformatted')
      READ(IOLD) CGBL
      CLOSE(IOLD,STATUS='KEEP')

      CALL  MAT_VEC (imeta,jmeta,NLEV,CGBL)

!====
      ALLOCATE(CXGBL(imeta,jmeta,NLEV))
      WRITE(TRYNAME,111) 
 111  FORMAT('tryfilt_incr')
      ITRY=22
      CLOSE(ITRY)
      OPEN(ITRY,file=TRYNAME,status='unknown',form='unformatted')
      READ(ITRY) CXGBL
      CLOSE(ITRY,STATUS='KEEP')

      CALL  MAT_VEC (imeta,jmeta,NLEV,CXGBL)

!----------------------------------------------------
!
!
!      EPSTOP and EPSBOT calculation
!

               do k=1,NLEV
              do j=1,jmeta
             do i=1,imeta
       EPSTOP=EPSTOP-CGBL(i,j,k)*(CXGBL(i,j,k)-CGBL(i,j,k))
       EPSBOT=EPSBOT+(CXGBL(i,j,k)-CGBL(i,j,k))*(CXGBL(i,j,k)-CGBL(i,j,k))
             end do
              end do
               end do

       DEALLOCATE(CGBL)
       DEALLOCATE(CXGBL)

!====
        END IF
!====
!
!---  write the step-length related sums
!
      IPEN=52
      CLOSE(IPEN)
      OPEN(IPEN,file='pensum',status='unknown',form='unformatted')
      WRITE(IPEN) EPSTOP,EPSBOT

       WRITE(*,*)"EPSTOP=",EPSTOP,"  EPSBOT=",EPSBOT
       WRITE(*,*) "       "
       WRITE(*,8888)
       WRITE(3,*)"EPSTOP=",EPSTOP,"  EPSBOT=",EPSBOT
       WRITE(3,*) "       "
       WRITE(3,8888)
 8888  FORMAT('END OF THE STEP_ETAFILT  '/)
!------
                             STOP
                             END