note 97369 added to function.stats-standard-deviation

If you don't have the stat package you can use these functions: <?php // Function to calculate square of value - mean function sd_square($x, $mean) { return pow($x - $mean,2); } // Function to calculate standard deviation (uses sd_square) function sd($array) { // square root of sum of squares devided by N-1 return sqrt(array_sum(array_map("sd_square", $array, array_fill(0,count($array), (array_sum($array) / count($array)) ) ) ) / (count($array)-1) ); } ?> ---- Server IP: 83.137.20.135 Probable Submitter: 145.18.152.143 ---- Manual Page -- http://www.php.net/manual/en/function.stats-standard-deviation.php Edit -- https://master.php.net/note/edit/97369 Del: integrated -- https://master.php.net/note/delete/97369/integrated Del: useless -- https://master.php.net/note/delete/97369/useless Del: bad code -- https://master.php.net/note/delete/97369/bad+code Del: spam -- https://master.php.net/note/delete/97369/spam Del: non-english -- https://master.php.net/note/delete/97369/non-english Del: in docs -- https://master.php.net/note/delete/97369/in+docs Del: other reasons-- https://master.php.net/note/delete/97369 Reject -- https://master.php.net/note/reject/97369 Search -- https://master.php.net/manage/user-notes.php