Details

Type: Improvement

Status: Closed

Priority: Minor

Resolution: Fixed

Affects Version/s: None

Fix Version/s: 0.20.0

Component/s: None

Labels:None

Hadoop Flags:Reviewed
Description
Currently, PiEstimator uses java.util.Random to generate random 2dpoints for estimating pi. The numbers generated by java.util.Random are uniformly distributed. The 2dpoints generated tense to have clump and gap. So the accuracy of the estimated pi is low. The accuracy can be improved by using a quasiMonte Carlo (qMC) sequence.
Issue Links
 is related to

MAPREDUCE638 Eliminate floating point arithmetic in PiEstimator
 Open
4437_20081019.patch: replace java.util.Random with Halton sequence.
Try totally 100000000 samples
Job Finished in 22.422 seconds
Estimated value of PI is 3.14145832
Job Finished in 13.375 seconds
Estimated value of PI is 3.14159256000000000000