SqrtDemo.java

package foo.ndkdemo;


public class SqrtDemo {

	public static final double EPSILON = 0.05d;

	public static native double sqrtC(double d);

	public static double sqrtJava(double d) {
		double x0 = 10.0, x1 = d, diff;
		do {
			x1 = x0 - (((x0 * x0) - d) / (x0 * 2));
			diff = x1 - x0;
//			Log.d("Java", 
//				String.format("x0=%12.8f, x1=%12.8f, diff=%12.8f\n", 
//					x0, x1, diff));
			x0 = x1;
		} while (Math.abs(diff) > EPSILON);
		return x1;
	}
}