经过两维数组从Fortran语言为C [英] Passing a two dimentional array from Fortran to C

问题描述

我有传递二维数组Fortran语言，从到C以下问题是我的C函数刚刚在屏幕上显示的数组元素。

I am having trouble passing a two dimensional array from Fortran to C. The following is my C function which just displays the array elements on the screen.

#include <stdio.h>
void print2(double *arr , int *n)
{
    int y = *n;
    printf("\n y = %d", y);
    for(int i =0; i<y; i++)
    {
          for (int j = 0; j < y; j++)
              printf("%.6g", *((arr + i*y) + j));
          printf("\n");
    }
}

我的Fortran code到目前为止是这样的：

My Fortran code so far is the following:

program linkFwithC
    use, intrinsic :: iso_c_binding
    implicit none
    real, dimension(3,3)::a
    a(1,1)=1
    a(1,2)=2
    a(1,3)=3
    a(2,1)=4
    a(2,2)=5
    a(2,3)=6
    a(3,1)=7
    a(3,2)=8
    a(3,3)=9

    interface
        subroutine print2(a,n) bind( c )
        use, intrinsic :: iso_c_binding
        type(c_ptr)::a
        integer(C_INT)::n
        end subroutine print2   
    end interface

    call print2(c_loc(a),3)
end program linkFwithC

我是连接这两个文件的方式是通过创建C函数静态库并建立的.lib文件。一旦文件.LIB建立我将它添加到FORTRAN项目并运行该Fortran项目。在code没有错误运行，并正确显示n值;然而，显示数组值都是错误的。

The way I am linking both files is by creating a static library for the C function and build the .lib file. Once the .lib file is built I add it to the fortran project and run the fortran project. The code runs with no errors and the n value is displayed correctly; However,the array values displayed are all wrong.

请帮帮忙！

谢谢，
阿纳斯

Thanks, Anas

推荐答案

进一步研究后，我能找到解决这个作品如下：

After further research I was able to find a work around this as follow:

以下是我的C函数：

#include <stdio.h>
  void print2(void *p, int n)
  {
     printf("Array from C is \n");
     double *dptr;
     dptr = (double *)p;
     for (int i = 0; i < n; i++)
     {
        for (int j = 0; j<n; j++)
            printf("%.6g \t",dptr[i*n+j]);

        printf("\n");
     }
  }

以下是我的Fortran code：

The following is my Fortran code:

        program linkFwithC
        use iso_c_binding
        implicit none 
        interface
          subroutine my_routine(p,r) bind(c,name='print2')
            import :: c_ptr
            import :: c_int
            type(c_ptr), value :: p
            integer(c_int), value :: r
          end subroutine
        end interface


        integer,parameter ::n=3
        real (c_double), allocatable, target :: xyz(:,:)
        real (c_double), target :: abc(3,3)
        type(c_ptr) :: cptr
        allocate(xyz(n,n))
        cptr = c_loc(xyz(1,1))

        !Inputing array valyes

        xyz(1,1)= 1
        xyz(1,2)= 2
        xyz(1,3)= 3
        xyz(2,1)= 4
        xyz(2,2)= 5
        xyz(2,3)= 6
        xyz(3,1)= 7
        xyz(3,2)= 8
        xyz(3,3)= 9


        call my_routine(cptr,n)
        deallocate(xyz)
      pause
      end program linkFwithC

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