GetTimeStepsFromFile Function

FUNCTION GetTimeStepsFromFile &
!
(filename) &
!
RESULT (steps)

IMPLICIT NONE

!Arguments with intent(in):
CHARACTER (LEN = *), INTENT(IN) :: filename

!Local declarations:
INTEGER (KIND = short) :: steps
INTEGER (KIND = short) :: ncStatus !!error code returned by NetCDF routines
INTEGER (KIND = short) :: ncId  !!NetCdf Id for the file
INTEGER (KIND = short) :: nDims !!number of dimensions
INTEGER (KIND = short) :: nDimsVar !!number of dimensions of a variable
INTEGER (KIND = short) :: nVars !!number of variables
INTEGER (KIND = short) :: nAtts !!number of global attributes
INTEGER (KIND = short) :: idTime !!Id of the variable containing 
                                 !!information on time coordinate  
INTEGER (KIND = short) :: dimId  !dimension id
CHARACTER (LEN = 80)   :: attribute
CHARACTER (LEN = 100)  :: variableName

INTEGER (KIND = short) :: i
INTEGER, DIMENSION(NF90_MAX_VAR_DIMS) :: dimIDs
!------------end of declaration------------------------------------------------

!open net-cdf file with read-only access
ncStatus = nf90_open (fileName, NF90_NOWRITE, ncId)
IF (ncStatus /= nf90_noerr) THEN
  CALL Catch ('error', 'GridLib',        &
  TRIM (nf90_strerror (ncStatus) )//': ',  &
  code = ncIOError, argument = fileName )
ENDIF

!search for "Time" dimension
ncStatus =  nf90_inq_dimid(ncid, "Time", dimId)
IF (ncStatus == nf90_noerr) THEN !Time dimension found
  ncStatus = nf90_inquire_dimension (ncId, dimId, len = steps)
  RETURN !no need to go on
END IF

!search for "time" dimension
ncStatus =  nf90_inq_dimid(ncid, "time", dimId)
IF (ncStatus /= nf90_noerr) THEN !time dimension found
  ncStatus = nf90_inquire_dimension (ncId, dimId, len = steps)
  RETURN !no need to go on
END IF

!If dimension has a different name, analyse variable

!inquire dataset to retrieve number of dimensions, variables 
!and global attributes
ncStatus = nf90_inquire(ncId, nDimensions = nDims, &
                        nVariables = nVars,        &
                        nAttributes = nAtts        )
                  
CALL ncErrorHandler (ncStatus)

!search for time variable
DO i = 1, nVars
  attribute = ''
  ncStatus = nf90_get_att (ncId, varid = i, name = 'standard_name', &
                           values = attribute)
  
  IF (ncStatus == nf90_noerr) THEN !standard_name is defined
    IF ( attribute(1:4) == 'time' ) THEN
      idTime = i 
      EXIT   
    END IF
  ELSE !standard_name is not defined: search for variable named 'time'
     !ncStatus = nf90_inq_varid (ncId, 'time', varid = i )
     ncstatus = nf90_inquire_variable(ncId, varId = i, name = variableName)
     IF (LEN_TRIM(variableName) == 4 .AND. &
         variableName(1:4) == 'time' .OR. &
         LEN_TRIM(variableName) == 5 .AND. &
         variableName(1:5) == 'Times' ) THEN !variable 'time' found
       idTime = i 
       EXIT 
     END IF
  END IF
END DO

!retrieve dimensions of variable
ncStatus = nf90_inquire_variable (ncId, idTime, ndims = nDimsVar)
CALL ncErrorHandler (ncStatus)

!retrieve dimension id of variable
ncStatus = nf90_inquire_variable(ncid, idTime, dimids = dimIDs)
CALL ncErrorHandler (ncStatus)

!inquire time length
IF (nDimsVar == 1) THEN
  ncStatus = nf90_inquire_dimension (ncId, dimid = dimIDs(1), len = steps)
  CALL ncErrorHandler (ncStatus)
ELSE IF (nDimsVar == 2) THEN
  ncStatus = nf90_inquire_dimension (ncId, dimid = dimIDs(2), len = steps)
  CALL ncErrorHandler (ncStatus)
END IF

RETURN

END FUNCTION GetTimeStepsFromFile