http://bugs.freedesktop.org/show_bug.cgi?id=6748
------- Comment #7 from [EMAIL PROTECTED] 2007-08-26 23:57 PST ------- Created an attachment (id=11287) --> (http://bugs.freedesktop.org/attachment.cgi?id=11287&action=view) Test program demonstrating instability of Shan Hao Bo's algorithm This code demonstrates a matrix inverse on a matrix with some near-zero elements. The result is shown for three inverse functions: 1) The pre-2006 Mesa implementation 2) The post-2006 implementation from Shan Hao Bo 3) A proposed replacement for both from me. As you can see, methods 1 and 3 agree on the answer, but 2 differs. It also shows timing characteristics for all three. Here is the output when run on my machine: Starting with matrix: -0.000000, -1.420000, 0.000000, 0.000000 1.710000, -0.000000, 0.302000, -0.000000 0.174000, -0.000000, -0.985000, 49.800000 0.174000, -0.000000, -0.985000, 50.000000 Inverse using original pre-2006 Mesa function: 0.000000, 0.567103, 43.468298, -43.294425 -0.704225, -0.000000, -0.000000, 0.000000 0.000000, 0.100179, -246.128443, 245.143929 0.000000, 0.000000, -5.000000, 5.000000 Inverse using Shan Hao Bo function (2006 onward): -4.000000, 0.567103, 43.468298, -43.294425 -0.704225, -0.000000, -0.000000, 0.000000 0.000000, 0.100179, -246.128443, 245.143929 0.000000, 0.000000, -5.000000, 5.000000 Inverse using Moore's proposed function: -0.000000, 0.567103, 43.468298, -43.294425 -0.704225, -0.000000, -0.000000, 0.000000 0.000000, 0.100179, -246.128443, 245.143929 0.000000, -0.000000, -5.000000, 5.000000 old function: 59094 ticks Shan Hao Bo function: 51597 ticks Moore function: 32796 ticks -- Configure bugmail: http://bugs.freedesktop.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug, or are watching the assignee. ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Mesa3d-dev mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mesa3d-dev
