Question

我需要读取一个模拟器的输出并存储值。文件名为forces.dat，包含与以下内容类似的内容：

# Forces     
# CofR       : (4.750000e-01 3.500000e-02 2.000000e-02)
# Time       forces(pressure viscous porous) moment(pressure viscous porous)
2.633022e-02    ((6.268858e-02 -1.468850e+01 1.542745e-20) (1.000906e-03 8.405854e-06 -5.657665e-17) (0.000000e+00 0.000000e+00 0.000000e+00)) ((-8.779466e-18 8.442993e-19 -3.225599e-03) (-2.082489e-18 4.435609e-18 -1.572485e-03) (0.000000e+00 0.000000e+00 0.000000e+00))
8.095238e-02    ((1.781333e-01 -1.468455e+01 -3.545427e-19) (2.362118e-03  2.014609e-05 1.691584e-16) (0.000000e+00 0.000000e+00 0.000000e+00))  ((-3.344781e-18 -5.448339e-19 2.227502e-02) (5.092628e-18 -3.538718e-18  -1.203074e-03) (0.000000e+00 0.000000e+00 0.000000e+00))
1.600000e-01    ((3.204471e-01 -1.467482e+01 -4.599174e-18) (6.936764e-03 1.303800e-04 4.836650e-17) (0.000000e+00 0.000000e+00 0.000000e+00)) ((-1.123589e-17 -4.344967e-19 5.591623e-02) (1.532415e-18 -1.345592e-18  -9.550750e-04) (0.000000e+00 0.000000e+00 0.000000e+00))

我想知道如何编写Fortran子程序来忽略前3行，然后读取下一行的数量，然后读取每行的值。

Answer 1

您可以使用此代码段来跟踪行号。根据您的要求和文件的性质，您可以获得相应行的值，并可以执行所需的操作。

--include-untracked

在上面的代码中，在(void)handlePinchGesture:(UIPinchGestureRecognizer *)gestureRecognizer { if([gestureRecognizer state] == UIGestureRecognizerStateBegan) { // Reset the last scale, necessary if there are multiple objects with different scales lastScale = [gestureRecognizer scale]; } if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) { CGFloat currentScale = [[[gestureRecognizer view].layer valueForKeyPath:@"transform.scale"] floatValue]; // Constants to adjust the max/min values of zoom const CGFloat kMaxScale = 2.0; const CGFloat kMinScale = 1.0; CGFloat newScale = 1 - (lastScale - [gestureRecognizer scale]); newScale = MIN(newScale, kMaxScale / currentScale); newScale = MAX(newScale, kMinScale / currentScale); CGAffineTransform transform = CGAffineTransformScale([[gestureRecognizer view] transform], newScale, newScale); [gestureRecognizer view].transform = transform; lastScale = [gestureRecognizer scale]; // Store the previous scale factor for the next pinch gesture call } }循环内部，您可以根据要读取的行放入文件处理逻辑。

Answer 2

虽然我认为通过某些命令行工具（例如sed -e 's/(/ /g' -e 's/)/ /g' input.dat）更容易预处理文件，但我们也可以直接使用Fortran将每行读入一个长字符串并删除所有不必要的括号：

program main
    implicit none
    integer, parameter :: mxline = 5000  !! choose appropriately
    integer i, ios, finp, nl
    character(500) str
    real, save :: time( mxline )
    real, dimension( 3, mxline ), save :: &
            frc_pres, frc_visc, frc_poro, &
            mom_pres, mom_visc, mom_poro

    finp = 10
    open( finp, file="input.dat", status="old" )

    nl = 0
    do
        read( finp, "(a)", iostat=ios ) str
        if ( ios /= 0 ) exit
        str = trim( adjustL( str ) )

        !! Skip comment or blank lines.
        if ( str(1:1) == "#" .or. str == "" ) cycle

        !! Replace parentheses with space.
        do i = 1, len_trim( str )
            if ( str(i:i) == "(" .or. str(i:i) == ")" ) str(i:i) = " "
        enddo

        !! Read data from the string.
        nl = nl + 1
        read( str, * ) time( nl ), &
                       frc_pres( :, nl ), frc_visc( :, nl ), frc_poro( :, nl ), &
                       mom_pres( :, nl ), mom_visc( :, nl ), mom_poro( :, nl )
    enddo

    close( finp )

    !! Check.
    do i = 1, nl
        print *
        print *, "time = ", time( i )
        print *, "frc_pres = ", frc_pres( :, i )
        print *, "frc_visc = ", frc_visc( :, i )
        print *, "frc_poro = ", frc_poro( :, i )
        print *, "mom_pres = ", mom_pres( :, i )
        print *, "mom_visc = ", mom_visc( :, i )
        print *, "mom_poro = ", mom_poro( :, i )
    enddo

end program

如果数据值变得非常大（例如，1.0e100），请考虑使用双精度实数，以免失去必要的精度。

如何读取混合文本文件并仅提取数字

2 个答案: