subroutine HistoryFileOpen
    !
    ! history_file_io モジュールの初期化を行います. 
    !
    !
    ! "history_file_io" module is initialized. 
    !
    !
    ! モジュール引用 ; USE statements
    !
    ! 出力ファイルの基本情報
    ! Basic information for output files
    ! 
    use fileset, only: FileTitle, FileSource, FileInstitution
                              ! データファイルを最終的に変更した組織/個人. 
                              ! Institution or person that changes data files for the last time
    ! 物理定数設定
    ! Physical constants settings
    !
    use constants, only: PI   ! $ \pi $ .
                              ! 円周率.  Circular constant
    ! 座標データ設定
    ! Axes data settings
    !
    use axesset, only: #ifdef LIB_MPI y_Lat_wholeMPI, z_Sigma_wholeMPI, r_Sigma_wholeMPI, #endif x_Lon_Weight, y_Lat, y_Lat_Weight, z_Sigma, r_Sigma, z_DelSigma, w_Number
                              ! スペクトルデータの添字番号. 
                              ! Subscript of spectral data
    ! NAMELIST ファイル入力に関するユーティリティ
    ! Utilities for NAMELIST file input
    !
    use namelist_util, only: namelist_filename, NmlutilMsg
    ! 時刻管理
    ! Time control
    !
    use timeset, only: StartTime, EndTime, StartDate, StartDateValid
    ! gtool4 netCDF データの入出力インターフェース (大規模モデル用)
    ! Interface of Input/Output of gtool4 netCDF data (For large models)
    !
    use gtool_historyauto, only: HistoryAutoCreate, HistoryAutoAddAttr, HistoryAutoAddWeight, HistoryAutoPutAxis, HistoryAutoPutAxisMPI
    ! ファイル入出力補助
    ! File I/O support
    !
    use dc_iounit, only: FileOpen
    ! 日付および時刻の取り扱い
    ! Date and time handler
    !
    use dc_date_types, only: DC_DIFFTIME
                              ! 日時の差を表現するデータ型. 
                              ! Data type for difference about date and time
    use dc_date, only: DCDiffTimeCreate
    ! 文字列操作
    ! Character handling
    !
    use dc_string, only: CPrintf
    ! 種別型パラメタ
    ! Kind type parameter
    !
    use dc_types, only: STDOUT ! 標準出力の装置番号. Unit number of standard output
    ! 宣言文 ; Declaration statements
    !
    implicit none
    ! 作業変数
    ! Work variables
    !
    type(DC_DIFFTIME):: DefaultInt
    logical:: flag_mpi_init
#ifdef LIB_MPI
    integer:: err_mpi
#endif
    ! 実行文 ; Executable statement
    !
    if ( history_file_io_inited ) return
    call InitCheck
    ! デフォルト値の設定
    ! Default values settings
    !
    DefaultIntValue = 1.0
    DefaultIntUnit  = 'day'
    DefaultFilePrefix = ''
!!$    DefaultIntValue = 1.0
!!$    DefaultIntUnit  = 'hrs'
!!$    DefaultFilePrefix = 'data01/'
    call DCDiffTimeCreate( DefaultInt, DefaultIntValue, DefaultIntUnit ) ! (in)
#ifdef LIB_MPI
    ! MPI における初期化が行われているかを確認する. 
    ! Confirm initialization of MPI
    !
    call MPI_Initialized(flag_mpi_init, err_mpi)
#else
    flag_mpi_init = .false.
#endif
    ! HistoryAutoCreate による初期化
    ! Initialization by "HistoryAutoCreate"
    !
    call HistoryAutoCreate( title = trim(FileTitle) // ' history data', source = FileSource, institution = FileInstitution, dims = (/ 'lon ', 'lat ', 'sig ', 'sigm', 'wn  ', 'time' /), dimsizes = (/ imax, jmax, kmax, kmax + 1, (nmax+1)**2, 0 /), longnames = (/ 'longitude                             ', 'latitude                              ', 'sigma at layer midpoints              ', 'sigma at layer end-points (half level)', 'subscript of spectral data            ', 'time                                  ' /), units = (/ 'degree_east ', 'degree_north', '1           ', '1           ', '1           ', DefaultIntUnit /), xtypes = (/ 'float', 'float', 'float', 'float', 'int  ', 'float' /), origin = StartTime, terminus = EndTime, interval = DefaultInt, origin_date = StartDate, origin_date_invalid = .not. StartDateValid, flag_mpi_gather = flag_mpi_init, file_prefix = DefaultFilePrefix, namelist_filename = namelist_filename )                ! (in) optional
    ! 座標データへの属性の設定
    ! Attributes of axes data settings
    !
    call HistoryAutoAddAttr( varname = 'lon', attrname = 'standard_name', value = 'longitude' )                            ! (in)
    call HistoryAutoAddAttr( varname = 'lat', attrname = 'standard_name', value = 'latitude' )                             ! (in)
    call HistoryAutoAddAttr( varname = 'sig', attrname = 'standard_name', value = 'atmosphere_sigma_coordinate' )          ! (in)
    call HistoryAutoAddAttr( varname = 'sigm', attrname = 'standard_name', value = 'atmosphere_sigma_coordinate' )          ! (in)
    call HistoryAutoAddAttr( varname = 'sig', attrname = 'positive', value = 'down' )                                 ! (in)
    call HistoryAutoAddAttr( varname = 'sigm', attrname = 'positive', value = 'down' )                                 ! (in)
    ! 座標データの設定
    ! Axes data settings
    !
    call HistoryAutoPutAxis( 'lon',  x_Lon / PI * 180.0_DP )  ! (in)
    call HistoryAutoPutAxis( 'lat',  y_Lat / PI * 180.0_DP )  ! (in)
    call HistoryAutoPutAxis( 'sig',  z_Sigma )                ! (in)
    call HistoryAutoPutAxis( 'sigm', r_Sigma )                ! (in)
    call HistoryAutoPutAxis( 'wn',   w_Number )               ! (in)
    ! 座標重みの設定
    ! Axes weights settings
    !
    call HistoryAutoAddWeight( dim = 'lon', weight = x_Lon_Weight, units = 'radian', xtype = 'double' )  ! (in) optional
    call HistoryAutoAddWeight( dim = 'lat', weight = y_Lat_Weight, units = 'radian', xtype = 'double' )  ! (in) optional
    call HistoryAutoAddWeight( dim = 'sig', weight = z_DelSigma, xtype = 'double' )                    ! (in) optional
#ifdef LIB_MPI
    ! MPI 使用時にファイルを一つに統合して出力するための情報の付与
    ! Add information for output to one file when MPI is used
    !
    call HistoryAutoPutAxisMPI( 'lon',  x_Lon_wholeMPI / PI * 180.0_DP )  ! (in)
    call HistoryAutoPutAxisMPI( 'lat',  y_Lat_wholeMPI / PI * 180.0_DP )  ! (in)
    call HistoryAutoPutAxisMPI( 'sig',  z_Sigma_wholeMPI )                ! (in)
    call HistoryAutoPutAxisMPI( 'sigm', r_Sigma_wholeMPI )                ! (in)
    call HistoryAutoPutAxisMPI( 'wn',   w_Number )                        ! (in)
#endif
    ! 印字 ; Print
    !
    call MessageNotify( 'M', module_name, '----- Initialization Messages -----' )
    call MessageNotify( 'M', module_name, '-- version = %c', c1 = trim(version) )
    history_file_io_inited = .true.
  end subroutine HistoryFileOpen