SUBROUTINE SETFGEFAMZ(CDFAM) 1
#if defined (DOC)
*
***s/r SETFGEFAMZ   - Interpolation of THE FIRST GUESS ERROR VARIANCES
*
*
*Author  :  J. St-James, CMDA/SMC November 2002
*Revision:
*          Y.J. Rochon *AQRX/MSC Feb 2005
*          - Added comnumbr.cdk 
*            as JPNBRELEM of comnumbr required by cvcord.
*
**    Purpose:  -Interpolate vertically the contents of commvo to
*                the levels of the observations (in meters). Then
*                compute THE FIRST GUESS ERROR VARIANCES
*                A linear interpolation in z is performed.
*
*
*
#endif
      IMPLICIT NONE
*implicits
#include "comdim.cdk"
#include "comdimo.cdk"
#include "comoabdy.cdk"
#include "comoahdr.cdk"
#include "comoba.cdk"
#include "commvo.cdk"
#include "commvog.cdk"
#include "comnumbr.cdk"
#include "cvcord.cdk"
#include "comcst.cdk"
*
      CHARACTER*2 CDFAM
      INTEGER IPB,IPT
      INTEGER IOBS,IPOS,IK,IBEGIN,ILAST
      INTEGER J,JDATA
      REAL*8 ZWB,ZWT
      REAL*8 ZLEV,ZPB,ZPT
C
      DO J = 1,NFILES
         IF ((CFAMTYP(J) .EQ. CDFAM).AND.(NBEGINTYP(J).GT.0)) THEN
            IBEGIN=NBEGINTYP(J)
            ILAST=NENDTYP(J)
C
C*    1. Computation of sigmap
C     .  -----------------------------
C
 100        CONTINUE
C
            DO JDATA=IBEGIN,ILAST
ccc   IF ( MOBDATA(NCMASS,JDATA) .EQ. 1) then
               IF ( MOBDATA(NCMASS,JDATA) .EQ. 1 .AND.
     &              MOBDATA(NCMVCO,JDATA) .EQ. 1 ) then
                  IF  (MOBDATA(NCMXTR,JDATA) .NE. 0) THEN
                     IK=NFLEV-1
                     IOBS = MOBDATA(NCMOBS,JDATA)
                     IPOS = MOBDATA(NCMPOS,JDATA)
                     IPT  = IK + IPOS*NFLEV
                     IPB  = IPT +1
                     ROBDATA(NCMFGE,JDATA) = GOMOBS(IPB,IOBS)
                  ELSE
                     IOBS = MOBDATA(NCMOBS,JDATA)
                     IPOS = MOBDATA(NCMPOS,JDATA)
                     ZLEV = ROBDATA8(NCMPPP,JDATA)
                     IK   = ROBDATA(NCMLYR,JDATA)
                     IPT  = IK + IPOS*NFLEV
                     IPB  = IPT+1
                     ZPT  = GOMGZG(IK,IOBS)/RG
                     ZPB  = GOMGZG(IK+1,IOBS)/RG
                     ZWB  = (ZPT-ZLEV)/(ZPT-ZPB)
                     ZWT  = 1. - ZWB

C
C     FIRST GUESS ERROR VARIANCE
C
                     ROBDATA(NCMFGE,JDATA) =
     +                    (ZWB*GOMOBS(IPB,IOBS) + ZWT*GOMOBS(IPT,IOBS))

                  ENDIF
               ENDIF
C
            END DO
C
         ENDIF
      END DO
C
      RETURN
      END