Bugs item #9360, was opened at 2007-03-18 23:41 You can respond by visiting: http://rubyforge.org/tracker/?func=detail&atid=1698&aid=9360&group_id=426 Category: Standard Library Group: 1.8.6 Status: Open Resolution: None Priority: 3 Submitted By: Stefan Mühlebach (muehlebach) Assigned to: Nobody (None) Summary: Matrix inverse problem Initial Comment: There is a problem with the Matrix.inverse method. Given the following matrix m = Matrix[[0.417787968829298, 0.542037605627772, 0.729142268138943], [0.0, 6.12303176911189e-17, 1.0], [-0.542037605627772, 0.417787968829298, -2.55812900589452e-17]] the result of m.inverse * m is [[1.0, 0.0, 0.650423523448542], [5.55111512312578e-17, 1.0, 0.84385869292008], [0.0, 9.24446373305873e-33, 1.0]] but it should be [[1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]] or close to this! ---------------------------------------------------------------------- You can respond by visiting: http://rubyforge.org/tracker/?func=detail&atid=1698&aid=9360&group_id=426