An example of roundoff error in linear scaling

gistfile1.txt

public class Calibration {

  private static double m = 0.235;
	private static double b = 0.33;

	private static double calibrated(double rawValue) {
		return m * rawValue + b;
	}

	private static double scale(double raw1, double raw2) {
		return (calibrated(raw2) - calibrated(raw1)) / (raw2 - raw1);
	}

	public static void run() {
		System.out.println(scale(0, 1));	// prints 0.23499999999999993
		System.out.println(scale(0.1, 1.1));	// prints 0.235
		System.out.println(scale(0, 499));	// prints 0.23499999999999996
	}

	public static void main(String[] args) {
		run();
	}
}