Matrix -> blocks division

Question

I want to load some matrix into my program and then I want to divide it into smaller blocks. What I want exactly can be seen on an image below:

http://postimg.org/image/aki19hjx9/ba463111/

In red squares are 3 examples of my "blocks" in which I would like to divide whole matrix. In this case each block should be (smaller) 3x3 matrix. I know how to load it into 2d array, but what should I do then?

Answer 1

int[][] bigMatrix = new int[9][9];
// initialize bigMatrix

int[][][] smallMatrices = new int[3][3][3];

for (int i = 0; i < 3; i++) {
    for (int j = 0; j < 3; j++) {
        for (int k = 0; k < 3; k++) {
            smallMatrices[i][j][k] = bigMatrix[3*i+j][3*i+k];
        }
    }
}

// The submatrices are now in smallMatrices[i], 0 <= i < 3