Question

我在FORTRAN 90中编写了一个小型测试用例程序，用于初始化切片中的3d数组。可以在C中轻松复制同样的行为吗？

  program fortranEngine

  real(4) , dimension(10,10) :: tmp
  real(4) , dimension(10,10,3) :: p    

  tmp = RESHAPE( [  0.973, 1.053, 0,     0,     0,     0,     0,     0,     0,     0, &
                    1.053, 1.080, 0,     0,     0,     0,     0,     0,     0,     0, &
                    1.010, 0.408, 0.442, 0,     0,     0,     0,     0,     0,     0, &
                    1.119, 0.900, 0.399, 0.762, 0,     0,     0,     0,     0,     0, &
                    1.211, 0.975, 0.845, 0.952, 1.105, 0,     0,     0,     0,     0, &
                    1.248, 1.016, 0.485, 0.000, 0.000, 1.110, 0,     0,     0,     0, &
                    1.225, 1.123, 1.056, 0.000, 0.000, 0.949, 0.832, 0,     0,     0, &
                    1.138, 1.232, 1.089, 1.050, 0.930, 0.402, 0.789, 0.774, 0,     0, &
                    1.149, 1.406, 1.201, 1.052, 0.416, 0.878, 0.896, 0.431, 1.144, 0, &
                    1.351, 1.255, 1.290, 1.358, 1.240, 1.228, 1.257, 1.140, 1.123, 1.228] &
                    , [10,10] )    

    p(:,:,1) = tmp    

    ...

    end program fortranEngine

Answer 1

您可以在C99或C2011中或多或少地执行此操作，但它不如Fortran中那么方便。当心initialization订单; Fortran以一个顺序（column-major）执行，C在另一个（row-major）中执行。忽略这一点，你可以这样做：

float tmp[10][10] =
{
    { 0.973, 1.053, 0,     0,     0,     0,     0,     0,     0,     0,    },
    { 1.053, 1.080, 0,     0,     0,     0,     0,     0,     0,     0,    },
    { 1.010, 0.408, 0.442, 0,     0,     0,     0,     0,     0,     0,    },
    { 1.119, 0.900, 0.399, 0.762, 0,     0,     0,     0,     0,     0,    },
    { 1.211, 0.975, 0.845, 0.952, 1.105, 0,     0,     0,     0,     0,    },
    { 1.248, 1.016, 0.485, 0.000, 0.000, 1.110, 0,     0,     0,     0,    },
    { 1.225, 1.123, 1.056, 0.000, 0.000, 0.949, 0.832, 0,     0,     0,    },
    { 1.138, 1.232, 1.089, 1.050, 0.930, 0.402, 0.789, 0.774, 0,     0,    },
    { 1.149, 1.406, 1.201, 1.052, 0.416, 0.878, 0.896, 0.431, 1.144, 0,    },
    { 1.351, 1.255, 1.290, 1.358, 1.240, 1.228, 1.257, 1.140, 1.123, 1.228 },
};
float p[3][10][10];    

for (int i = 0; i < 3; i++)
    memmove(p[i], tmp, sizeof(tmp));

请注意，我将维度[3]从声明的末尾移动到声明的开头。另外一种方式在C语言中没有多大意义。因此，符号或多或少可用，但存储管理的细节使得如何实现你想要的东西并不明显。

Answer 2

这很容易吗？

for(int i = 0 ; i < 10 ; ++i) 
    for(int j = 0 ; j < 10 ; ++j )
        p[0][i][j] = tmp[i][j] ;

在C中初始化一个类似于Fortran的多维数组

2 个答案: