cvs: pear /Math_Matrix Matrix.php

jmcastagnetto Tue May 28 05:27:07 2002 EDT Modified files: /pear/Math_Matrix Matrix.php Log: Added trace() method. TODO: add Gauss-Jordan determinant algorithm, good for big matrices. Index: pear/Math_Matrix/Matrix.php diff -u pear/Math_Matrix/Matrix.php:1.3 pear/Math_Matrix/Matrix.php:1.4 --- pear/Math_Matrix/Matrix.php:1.3 Tue May 28 05:12:53 2002 +++ pear/Math_Matrix/Matrix.php Tue May 28 05:27:07 2002 @@ -18,7 +18,7 @@ // // Matrix definition and manipulation package // -// $Id: Matrix.php,v 1.3 2002/05/28 09:12:53 jmcastagnetto Exp $ +// $Id: Matrix.php,v 1.4 2002/05/28 09:27:07 jmcastagnetto Exp $ // require_once 'PEAR.php'; @@ -201,6 +201,17 @@ return $this->_data[$row][$col]; }/*}}}*/ + function trace() { + if ($this->isEmpty()) + return PEAR::raiseError('Matrix has not been populated'); + if (!$this->isSquare()) + return PEAR::raiseError('Trace undefined for non-square matrices'); + $trace = 0; + for ($i=0; $i < $this->_nrows; $i++) + $trace += $this->getElement($i, $i); + return $trace; + } + function determinant() { if ($this->isEmpty()) return PEAR::raiseError('Matrix has not been populated');