我想学习如何从主机内存复制一个3维数组到设备内存中。 可以说我有一个三维数组，它包含的数据。例如 INT HOST_DATA [256] [256] [256]; 我要复制的数据到dev_data（一个元件阵列）以这样的方式，以便 HOST_DATA [X] [Y] [Z] = dev_data [X] [Y] [Z]。 我怎样才能做到这一点？而我怎么来访问设备的dev_data阵列？ 一个简单的例子是非常有益的。

I want to learn how can i copy a 3 dimensional array from host memory to device memory. Lets say i have a 3d array which contains data. For example int host_data[256][256][256]; I want to copy that data to dev_data (a device array) in such a way so host_data[x][y][z]=dev_data[x][y][z]; How can i do it? and how am i supposed to access the dev_data array in the device? A simple example would be very helpfull.

推荐答案

的常用方法是变平的阵列（使其一维）。然后，你就必须做一些计算，从地图（X，Y，Z）三到一个数字 - 在一个扁平的一维数组的位置。

The common way is to flatten an array (make it one-dimensional). Then you'll have to make some calculations to map from (x,y,z) triple to one number - a position in a flattened one-dimensional array.

例2D：

int data[256][256];
int *flattened = data;
data[x][y] == fattened[x * 256 + y];

例如3D：

int data[256][256][256];
int *flattened = data;
data[x][y][z] == flattened[x * 256 * 256 + y * 256 + z];

或使用包装：

or use a wrapper:

__host__ __device___ inline int index(const int x, const int y, const int z) {
     return x * 256 * 256 + y * 256 + z;
}

知道了，你可以分配一个与cudaMalloc线性阵列，像往常一样，然后用首页函数访问设备code对应的元素。

Knowing that, you can allocate a linear array with cudaMalloc, as usual, then use an index function to access corresponding element in device code.

更新： 的作者this问题声称已经找到了更好的解决方案（至少在2D），你可能想看看。

Update: The author of this question claims to have found a better solution (at least for 2D), you might want to have a look.