Author: luc
Date: Wed May 30 09:22:58 2012
New Revision: 1344166
URL: http://svn.apache.org/viewvc?rev=1344166&view=rev
Log:
Yet another attempt at computing hash for OrederedTuple.
JIRA: MATH-793
Modified:
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/geometry/partitioning/utilities/OrderedTuple.java
Modified:
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/geometry/partitioning/utilities/OrderedTuple.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math3/geometry/partitioning/utilities/OrderedTuple.java?rev=1344166&r1=1344165&r2=1344166&view=diff
==============================================================================
---
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/geometry/partitioning/utilities/OrderedTuple.java
(original)
+++
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/geometry/partitioning/utilities/OrderedTuple.java
Wed May 30 09:22:58 2012
@@ -301,10 +301,23 @@ public class OrderedTuple implements Com
/** {@inheritDoc} */
@Override
public int hashCode() {
- return Arrays.hashCode(components) * offset * (lsb << 7) +
- ((posInf ? 43422 : 875342) *
- (negInf ? 86535631 : 632442767) *
- (nan ? 51108941 : 64234));
+ // the following constants are arbitrary small primes
+ final int multiplier = 37;
+ final int trueHash = 97;
+ final int falseHash = 71;
+
+ // hash fields and combine them
+ // (we rely on the multiplier to have different combined weights
+ // for all int fields and all boolean fields)
+ int hash = Arrays.hashCode(components);
+ hash = hash * multiplier + offset;
+ hash = hash * multiplier + lsb;
+ hash = hash * multiplier + (posInf ? trueHash : falseHash);
+ hash = hash * multiplier + (negInf ? trueHash : falseHash);
+ hash = hash * multiplier + (nan ? trueHash : falseHash);
+
+ return hash;
+
}
/** Get the components array.
