hadoop-common-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Tsz Wo (Nicholas), SZE (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HADOOP-5819) Check in the codes that compute the 10^15+1st bit of π
Date Wed, 20 May 2009 07:42:45 GMT

    [ https://issues.apache.org/jira/browse/HADOOP-5819?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12711048#action_12711048
] 

Tsz Wo (Nicholas), SZE commented on HADOOP-5819:
------------------------------------------------

Computed the following table for the bits of &pi;:
|| || Position || &pi; bits (in hex) ||
|  0 |                     1 | 243F6A8885A3 |
|  1 |                    11 | FDAA22168C23 |
|  2 |                   101 | 3707344A409  |
|  3 |                 1,001 | 574E69A458F  |
|  4 |                10,001 | 44EC5716F2B  |
|  5 |               100,001 | 944F7A204    |
|  6 |             1,000,001 | 6FFFA4103    |
|  7 |            10,000,001 | 6CFDD54E3    |
|  8 |           100,000,001 | A306CFA7     |
|  9 |         1,000,000,001 | 3E08FF2B     |
| 10 |        10,000,000,001 | 0A8BD8C0     |
| 11 |       100,000,000,001 | B2238C1      |
| 12 |     1,000,000,000,001 | 0FEE563      |
| 13 |    10,000,000,000,001 | 896DC3       |
| 14 |   100,000,000,000,001 | C216EC       |
| 15 | 1,000,000,000,000,001 | 6216B06      |

- For each position n, except the first and the last, also computed &pi; bits at position
n-4 and n+4 for correctness checking.

- Row 0 to Row 7 were run in a single computer.  A single run of Row 7 took several seconds.

- Row 8 to Row 14 were run in a 7600-cpu-core cluster.  A single run of Row 14 took 27 hours.

- Row 15 is the result reported in [the YDN blog|http://developer.yahoo.net/blogs/hadoop/2009/05/hadoop_computes_the_10151st_bi.html].

> Check in the codes that compute the 10^15+1st bit of π
> ------------------------------------------------------
>
>                 Key: HADOOP-5819
>                 URL: https://issues.apache.org/jira/browse/HADOOP-5819
>             Project: Hadoop Core
>          Issue Type: Improvement
>          Components: examples
>            Reporter: Tsz Wo (Nicholas), SZE
>            Assignee: Tsz Wo (Nicholas), SZE
>         Attachments: 1e15log.zip, 5819_20090515.patch
>
>
> We have an improved version of the current BaileyBorwinPlouffe example, which able to
compute at least the10^15+1st bit of π.  See also http://developer.yahoo.net/blogs/hadoop/2009/05/hadoop_computes_the_10151st_bi.html

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message