Modify hypotenuse scaling formula for x^2+y^2 in log().
The modification change uses the method from FastMath.hypot().
diff --git a/commons-numbers-complex/src/main/java/org/apache/commons/numbers/complex/Complex.java b/commons-numbers-complex/src/main/java/org/apache/commons/numbers/complex/Complex.java
index 7a4dd6c..8987031 100644
--- a/commons-numbers-complex/src/main/java/org/apache/commons/numbers/complex/Complex.java
+++ b/commons-numbers-complex/src/main/java/org/apache/commons/numbers/complex/Complex.java
@@ -94,8 +94,8 @@
private static final double HALF = 0.5;
/** {@code sqrt(2)}. */
private static final double ROOT2 = Math.sqrt(2);
- /** The number of bits of precision of the mantissa of a {@code double} + 1: {@code 54}. */
- private static final double PRECISION_1 = 54;
+ /** Half the number of bits of precision of the mantissa of a {@code double} rounded up: {@code 27}. */
+ private static final double HALF_PRECISION = 27;
/** The bit representation of {@code -0.0}. */
private static final long NEGATIVE_ZERO_LONG_BITS = Double.doubleToLongBits(-0.0);
/** Exponent offset in IEEE754 representation. */
@@ -2340,7 +2340,9 @@
// Do scaling
final int expx = Math.getExponent(x);
final int expy = Math.getExponent(y);
- if (2 * (expx - expy) > PRECISION_1) {
+ // Hull et al: 2 * (expx - expy) > precision + 1
+ // Modified to use the pre-computed half precision
+ if ((expx - expy) > HALF_PRECISION) {
// y can be ignored
re = log.apply(x);
} else {
