note 101392 added to function.exp

PHP does not have the following math function in any extensions: frexp() - Extract Mantissa and Exponent of the Floating-Point Value I've digged many C source codes, and found the simplest implementation as follows: <?php function frexp ( $float ) { $exponent = ( floor(log($float, 2)) + 1 ); $mantissa = ( $float * pow(2, -$exponent) ); return( array($mantissa, $exponent) ); } print_r(frexp(0.0345)); print_r(frexp(21.539)); ?> Array ( [0] => 0.552 [1] => -4 ) Array ( [0] => 0.67309375 [1] => 5 ) I have compared the results using a lot of floats against C's frexp function - they are the same. Note that C and PHP uses different float precisions, for example "4619.3" gives: C: 0.56387939453125, 13 PHP: 0.563879394531, 13 /Assuming default configurations./ ---- Server IP: 212.124.37.9 Probable Submitter: 80.77.114.203 ---- Manual Page -- http://www.php.net/manual/en/function.exp.php Edit -- https://master.php.net/note/edit/101392 Del: integrated -- https://master.php.net/note/delete/101392/integrated Del: useless -- https://master.php.net/note/delete/101392/useless Del: bad code -- https://master.php.net/note/delete/101392/bad+code Del: spam -- https://master.php.net/note/delete/101392/spam Del: non-english -- https://master.php.net/note/delete/101392/non-english Del: in docs -- https://master.php.net/note/delete/101392/in+docs Del: other reasons-- https://master.php.net/note/delete/101392 Reject -- https://master.php.net/note/reject/101392 Search -- https://master.php.net/manage/user-notes.php