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我正在使用fortran f95。我的操作系统是 Windows 7、64 位。

我想将输出保存到一个 excel 文件中，以便我可以绘制数据。有人知道怎么做这个吗？非常感谢您的回复。PS：我希望输出文件包含 x、f(i)、fprime1、fprime2、fprime3、diff1、diff2 和 diff3。代码如下所述：

**

! This program calculates the first derivative of
! a function, where f(x)= sin x. It makes use of the
! centred-difference formula using 3 values of the step size: h1, h2, h3.
! It also calculates the
! analytical first derivative of the function.
Program centred_difference_first_derivative
implicit none
real :: x, h1, h2, h3, fprime1, fprime2, fprime3, diff1, diff2, diff3, pi, stepa
real,dimension(:), allocatable :: f
integer :: i
! Assignment of variables
x=0.0
pi=4*atan2(1.0,1.0)
allocate(f(41))
stepa=pi/20.0
h1=0.1
h2=0.01
h3=0.001
! Calculate analytical derivative of sin x
! for the domain x:[0,2pi]
do i=1,41
  f(i)=cos(x)
  x=x+stepa
  end do

! Approximates first derivative of sin x
! step size h1, for the domain x:[0,2pi]
  x=0.0
do i=1,41
  fprime1=(sin(x+h1)-sin(x-h1))/(2*h1)
  diff1=f(i)-fprime1
  print 37, x,f(i),fprime1,diff1
  x=x+stepa
  end do
37  format(e15.8,3x,e15.8,3x,e15.8,3x,'ERROR1= ',e15.8)

! Approximates first derivative of sin x
! step size h2, for the domain x:[0,2pi]
  x=0.0
do i=1,41
  fprime2=(sin(x+h2)-sin(x-h2))/(2*h2)
  diff2=f(i)-fprime2
  print 49,x,f(i),fprime2,diff2    
  x=x+stepa
  end do
49  format(e15.8,3x,e15.8,3x,e15.8,3x,'ERROR2= ',e15.8)
! Approximates first derivative of sin x
! step size h3, for the domain x:[0,2pi]
  x=0.0
do i=1,41
  fprime3=(sin(x+h3)-sin(x-h3))/(2*h3)
  diff3=f(i)-fprime3
print 61,x,f(i),fprime3,diff3    
  x=x+stepa
  end do
61  format(e15.8,3x,e15.8,3x,e15.8,3x,'ERROR3= ',e15.8)
end program

**

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1 回答 1

1

将数据输出到文件，以空格或逗号分隔。Excel 具有文本导入功能，可以正确处理和显示此类文件。

一个示例是 ASCII tecplot 文件，您可以使用 Fortran 简单地编写它，这里提供了源代码和示例 - TECPLOT_WRITE。下面是一个简短的片段。

!
!  Write the zone header.
!
  write ( iunit, '(a)' ) ' '
  write ( iunit, '(a,i6,a,i6,a,i6,a)' ) 'Zone I=', nr, ', J=', nz, 'K=', &
    nt, ', F=POINT'
!
!  Write the zone data, one node at a time.
!
  do k = 1, nt
    do j = 1, nz
      do i = 1, nr

        x = r(i) * cos ( t(k) )
        y = r(i) * sin ( t(k) )

        vx = vr(i,j) * cos ( t(k) ) - vt(i,j) * sin ( t(k) )
        vy = vr(i,j) * sin ( t(k) ) + vt(i,j) * cos ( t(k) )

        write ( iunit, '(3f10.3,3g15.6)' ) x, y, z(j), vx, vy, vz(i,j)

      end do
    end do
  end do
于 2013-12-18T22:48:37.280 回答