From issues-return-14952-apmail-commons-issues-archive=commons.apache.org@commons.apache.org Wed Sep 01 23:37:34 2010 Return-Path: Delivered-To: apmail-commons-issues-archive@minotaur.apache.org Received: (qmail 73593 invoked from network); 1 Sep 2010 23:37:34 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 1 Sep 2010 23:37:34 -0000 Received: (qmail 31978 invoked by uid 500); 1 Sep 2010 23:37:34 -0000 Delivered-To: apmail-commons-issues-archive@commons.apache.org Received: (qmail 31747 invoked by uid 500); 1 Sep 2010 23:37:33 -0000 Mailing-List: contact issues-help@commons.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: issues@commons.apache.org Delivered-To: mailing list issues@commons.apache.org Received: (qmail 31739 invoked by uid 99); 1 Sep 2010 23:37:33 -0000 Received: from Unknown (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 01 Sep 2010 23:37:33 +0000 X-ASF-Spam-Status: No, hits=-2000.0 required=10.0 tests=ALL_TRUSTED X-Spam-Check-By: apache.org Received: from [140.211.11.22] (HELO thor.apache.org) (140.211.11.22) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 01 Sep 2010 23:37:15 +0000 Received: from thor (localhost [127.0.0.1]) by thor.apache.org (8.13.8+Sun/8.13.8) with ESMTP id o81NasE6025289 for ; Wed, 1 Sep 2010 23:36:54 GMT Message-ID: <20938791.128031283384214111.JavaMail.jira@thor> Date: Wed, 1 Sep 2010 19:36:54 -0400 (EDT) From: "William Rossi (JIRA)" To: issues@commons.apache.org Subject: [jira] Commented: (MATH-375) Elementary functions in JDK are slower than necessary and not as accurate as they could be. In-Reply-To: <25525697.36411276039695053.JavaMail.jira@thor> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 X-Virus-Checked: Checked by ClamAV on apache.org [ https://issues.apache.org/jira/browse/MATH-375?page=3Dcom.atlassian.j= ira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=3D129053= 14#action_12905314 ]=20 William Rossi commented on MATH-375: ------------------------------------ Thanks Jeff. I will take a look at your tests. As for my test, the last = number on the line shows the error in ULPs, so its just outside the thresho= ld. I may have set the tolerance a bit too tight. > Elementary functions in JDK are slower than necessary and not as accurate= as they could be. > -------------------------------------------------------------------------= ------------------ > > Key: MATH-375 > URL: https://issues.apache.org/jira/browse/MATH-375 > Project: Commons Math > Issue Type: New Feature > Environment: JDK 1.4 - 1.6 > Reporter: William Rossi > Fix For: 2.2 > > Attachments: atanpatch.txt.gz, FastMath.tar.gz, test_fastmath_wr.= zip > > > I would like to contribute improved versions on exp(), log(), pow(), etc.= to the project. Please refer to this discussion thread http://markmail.o= rg/message/zyeoguw6gwtofm62. > I have developed over the past year a set of elementary functions similar= to those in java.lang.Math, but with the following characteristics: > * Higher performance. > * Better accuracy. Results are accurate to slightly more that +/- 0.5 UL= P. > * Pure Java. The standard Math class is impleneted via JNI, and thus tak= es a performance hit. > Note that some functions such as exp are nearly twice as fast in my imple= mentation. =C2=A0 I've seen it 3 times faster on different processors. =C2= =A0 The preformance varies by the relative speed of calculation vs memory l= ookups. > The functions are implemented as tables of values in extra precision (app= rox 70 bits), and then interpolated with a minimax polynomial. --=20 This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.