2D fluid height field

Wave.java

public class Wavey {
	private static int DELTA_T = 1;
	private static float speed = 0.01F;
	
	private float[] u = new float[20];
	private float[] v = new float[u.length];
	private float h = 0.1F;
	private int frame = 0;
	
	private float damping = 0.99F;
	
	public static void main(String[] args) {
		new Wavey();
	}
	
	private void render() {
		float[] u_new = new float[u.length]; 
		
		for (int i = 0; i < u.length; i++) {
			float f = speed * speed * (u(i - 1) + u(i + 1) - 2 * u(i)) / (h * h);
			v[i] = damping * v[i] + f * DELTA_T;
			u_new[i] = u[i] + v[i] * DELTA_T;
		}
		u = u_new;
		
		clear();
		draw();
		waitForNextFrame();
		render();
	}
	
	private float u(int i) {
		int boundIndex = Math.min(
				Math.max(i, 0), 
				u.length - 1);
		return u[boundIndex];
	}
	
	
	
	private void draw() {
		StringBuilder s = new StringBuilder();
		for(float level = 1.0F; level >= 0.0; level -= 0.1) {
			for (int i = 0; i < u.length; i++) {
				if (u[i] >= level) {
					s.append("#");
				} else {
					s.append(" ");
				}
			}
			s.append(System.lineSeparator());
		}
		s.append("(Frame: " + frame + ")");
		System.out.println(s);
	}

	public Wavey() {
		for (int i = 0; i < u.length; i++) {
			u[i] = 0.5F;
		}
		u[4] = 0.7F;
		u[5] = 0.8F;
		u[6] = 0.7F;
		draw();
		render();
	}

	private void clear() {  
		for (int i = 0; i < 50; ++i) System.out.println();
	}

	private void waitForNextFrame() {
		try {
			Thread.sleep(33);
			frame++;
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}  
}