FloatCmppublic class FloatCmp extends Object | Floating-point comparisons. |
| Fields Summary |
|---|
| static final double | EPSILON |
| Methods Summary |
|---|
| public static boolean | equals(double a, double b, double eps)Compare two doubles within a given epsilon
if (a==b) return true;
// If the difference is less than epsilon, treat as equal.
return Math.abs(a - b) < eps;
| | public static boolean | equals(double a, double b)Compare two doubles, using default epsilon
if (a==b) return true;
// If the difference is less than epsilon, treat as equal.
return Math.abs(a - b) < EPSILON * Math.max(Math.abs(a), Math.abs(b));
| | public static void | main(java.lang.String[] argv)
double da = 3 * .3333333333;
double db = 0.99999992857;
// Compare two numbers that are expected to be close.
if (da == db) {
System.out.println("Java considers " + da + "==" + db);
// else compare with our own equals method
} else if (equals(da, db, 0.0000001)) {
System.out.println("True within epsilon " + EPSILON);
} else {
System.out.println(da + " != " + db);
}
// Show that comparing two NaNs is not a good idea:
double d1 = Double.NaN;
double d2 = Double.NaN;
if (d1 == d2)
System.err.println("Comparing two NaNs incorrectly returns true.");
if (!new Double(d1).equals(new Double(d2)))
System.err.println("Double(NaN).equal(NaN) incorrectly returns false.");
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