How to add an offset to simplex noise?

I am working on a small summer project and this project got me into procedurally generated terrain for the first time. So I found this code online and it worked pretty well.

Code: `

import java.util.Random;

public class SimplexNoise {

/** Source of entropy */
private Random rand_;

/** Amount of roughness */
float roughness_;

/** Plasma fractal grid */
private float[][] grid_;

private int Xoffset_, Yoffset_;

/**
 * Generate a noise source based upon the midpoint displacement fractal.
 * 
 * @param rand
 *            The random number generator
 * @param roughness
 *            a roughness parameter
 * @param width
 *            the width of the grid
 * @param height
 *            the height of the grid
 */
public SimplexNoise(Random rand, float roughness, int width, int height) {
    roughness_ = roughness / width;
    grid_ = new float[width][height];
    rand_ = (rand == null) ? new Random() : rand;
}

public void initialise() {
    int xh = grid_.length - 1;
    int yh = grid_[0].length - 1;

    // set the corner points
    grid_[0][0] = rand_.nextFloat() - 0.5f;
    grid_[0][yh] = rand_.nextFloat() - 0.5f;
    grid_[xh][0] = rand_.nextFloat() - 0.5f;
    grid_[xh][yh] = rand_.nextFloat() - 0.5f;

    // generate the fractal
    generate(0, 0, xh, yh);
}

// Add a suitable amount of random displacement to a point
private float roughen(float v, int l, int h) {
    return v + roughness_ * (float) (rand_.nextGaussian() * (h - l));
}

// generate the fractal
private void generate(int xl, int yl, int xh, int yh) {
    int xm = (xl + xh) / 2;
    int ym = (yl + yh) / 2;
    if ((xl == xm) && (yl == ym))
        return;

    grid_[xm][yl] = 0.5f * (grid_[xl][yl] + grid_[xh][yl] );
    grid_[xm][yh] = 0.5f * (grid_[xl][yh] + grid_[xh][yh] );
    grid_[xl][ym] = 0.5f * (grid_[xl][yl] + grid_[xl][yh]) ;
    grid_[xh][ym] = 0.5f * (grid_[xh][yl] + grid_[xh][yh]) ;

    float v = roughen(0.5f * (grid_[xm][yl] + grid_[xm][yh]), xl + yl, yh + xh);
    grid_[xm][ym] = v;
    grid_[xm][yl] = roughen(grid_[xm][yl], xl, xh);
    grid_[xm][yh] = roughen(grid_[xm][yh], xl, xh);
    grid_[xl][ym] = roughen(grid_[xl][ym], yl, yh);
    grid_[xh][ym] = roughen(grid_[xh][ym], yl, yh);

    generate(xl, yl, xm, ym);
    generate(xm, yl, xh, ym);
    generate(xl, ym, xm, yh);
    generate(xm, ym, xh, yh);
}

/**
 * Dump out as a CSV
 */
public void printAsCSV() {
    for (int i = 0; i < grid_.length; i++) {
        for (int j = 0; j < grid_[0].length; j++) {
            System.out.print(grid_[i][j]);
            System.out.print(",");
        }
        System.out.println();
    }
}

/**
 * Convert to a Boolean array
 * 
 * @return the boolean array
 */
public boolean[][] toBooleans() {
    int w = grid_.length;
    int h = grid_[0].length;
    boolean[][] ret = new boolean[w][h];
    for (int i = 0; i < w; i++) {
        for (int j = 0; j < h; j++) {
            ret[i][j] = grid_[i][j] < 0;
        }
    }
    return ret;
}

public float[][] getGrid_() {
    return grid_;
}




}`

But then I wanted to generate the next chunk so I thought I will have to add some kind of offset somewhere in the noise generation to create the float[][] that would be next to my initial Chunk. Each Chunk has an xID and a yID those tell the renderer where to draw the tiles that are in the chunk. So when the xID and the yID are 0 the tiles will draw from X = 0,Y = 0 till X = 3200, Y = 3200. (Each chunk is 100*100 tiles and each tile is 32*32 pixel). I think the Offset would be the location of the chunk I want to generate so when I want to generate Chunk(1, 0) it would be offsetX = (1 * 3200) and offsetY = (0 * 3200). But where should I add this values? I thought here at first but after re thinking it I saw that it would not work cause that wil cause an ArrayOutOfBounds Exception.

here: int xm = (xl + xh) / 2 + offsetX; int ym = (yl + yh) / 2 + offsetY;

Here are some of my notes (I know my handwriting is awful)ABCD is my initial chunk and BEDF is the chunk that I want to generate.

Notes

So can anyone explain to me how I am going to do this?

(English is not my main language).