Author: tn
Date: Sun May 12 15:57:50 2013
New Revision: 1481590
URL: http://svn.apache.org/r1481590
Log:
Improve gray code calculation.
Modified:
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/random/SobolSequenceGenerator.java
Modified:
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/random/SobolSequenceGenerator.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math3/random/SobolSequenceGenerator.java?rev=1481590&r1=1481589&r2=1481590&view=diff
==============================================================================
---
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/random/SobolSequenceGenerator.java
(original)
+++
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/random/SobolSequenceGenerator.java
Sun May 12 15:57:50 2013
@@ -277,7 +277,7 @@ public class SobolSequenceGenerator impl
Arrays.fill(x, 0);
} else {
final int i = index - 1;
- final long grayCode = i ^ (i / 2);
+ final long grayCode = i ^ (i >> 1); // compute the gray code of i
= i XOR floor(i / 2)
for (int j = 0; j < dimension; j++) {
long result = 0;
for (int k = 1; k <= BITS; k++) {
