CUDA矩阵加法块、线程与数组间的理解

global void MatAdd(float A[N][N], float B[N][N], float C[N][N]) {

int i = blockIdx.x * blockDim.x + threadIdx.x;

int j = blockIdx.y * blockDim.y + threadIdx.y;

if (i < N && j < N)

C[i][j] = A[i][j] + B[i][j];

}

图中blockDim.x=4,blockDim.y=3
代码中用block(1,1)和thread(1,1)求出的i=5,j=4代表什么意思？刚学这块，不是很懂

http://blog.csdn.net/qq_25819827/article/details/51956774