utils.f90

集合卡尔曼滤波(EnKF) 数据同化方法可以避免了EKF 中协方差演变方程预报过程中出现的计算不准确和关于协方差矩阵的大量数据的存储问题,最主要的是可以有效的控制估计误差方差的增长,改善预报的效果。

!! Copyright (C) 2008 Pavel Sakov
!! 
!! This file is part of EnKF-Matlab. EnKF-Matlab is a free software. See 
!! LICENSE for details.

! File:           utils.f90
!
! Created:        31/08/2007
!
! Last modified:  08/02/2008
!
! Author:         Pavel Sakov
!                 CSIRO Marine and Atmospheric Research
!                 NERSC
!
! Purpose:        Fortran code for QG model. Utilities.
!
! Description:    
!
! Revisions:

module utils_mod

  implicit none

  save

  public wopen, strcmp

  ! Define number for standard output file
  integer, parameter, public :: stdout = 6
  ! Define default verbosity
  integer, parameter, public :: VERBOSE_DEF = 1
  ! String length
  integer, parameter, public :: STRLEN = 1024

contains

  subroutine wopen(fname, fid, mode)
    !
    ! Wrapper to open().
    !
    character(*) :: fname
    integer :: fid
    character(*) :: mode
    integer ios

    open(unit = fid, file = trim(fname), status = trim(mode), iostat = ios)
    if (ios /= 0) then
       write(stdout, *) '  qg: error: wopen(): could not open ' // trim(fname) // ' in mode = ' //  mode
       call flush(stdout)
       stop
    end if
  end subroutine wopen

  function strcmp(string1, string2)
    !
    ! Compares two strings, a-la C
    !
    integer :: strcmp
    character(*) :: string1
    character(*) :: string2

    if (LGT(trim(string1), trim(string2))) then
       strcmp = 1
    else if (LGT(trim(string2), trim(string1))) then
       strcmp = -1
    else
       strcmp = 0
    end if
  end function strcmp

end module utils_mod