note 99788 added to ref.gmp

From: Date: Tue, 07 Sep 2010 03:02:06 +0000
Subject: note 99788 added to ref.gmp
Groups: php.notes 
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I made a function that can be used for converting numbers to any base you wish.. instead of returning a string of pre-defined index of characters (i.e. 0-9a-z) you could simply make your own of any length using the array of indexes it returns. I looked around and didn't see anybody made one, I needed one for a simple compression algorithm with only numbers, I've not actually made it yet but this was an initial idea. <?php // ConvertBase function explained: // we add an array item $Input%$Base floored and divide $Input by $Base floored. // repeat until $Input is no longer above 0. function ConvertBase($Input,$Base=10) { $Input=gmp_init($Input); $Result=array(); for($i=0;$i<1||gmp_sign($Input)==1;$i++) { $Result[]=gmp_intval(gmp_mod($Input,$Base)); $Input=gmp_div_q($Input,$Base); } $Result=array_reverse($Result); return($Result); } // an example how gmp_strval($.., 36); could be achieved: // the funny emergency number from The IT Crowd // (leading zeroes aren't liked in gmp_init though) $Input = '1189998819991197253'; // our example 36 characters used in gmp_strval($.., 36); $Chars = '0123456789abcdefghijklmnopqrstuvwxyz'; // count the $Chars so they're all used // or use your own number less than the length of $Chars $Base = strlen($Chars); // perform $Result = ConvertBase($Input,$Base); // replace the resulting index with the corrosponding characters of the index in $Chars for($i=0;$i<count($Result);$i++) $Result[$i]=$Chars{$Result[$i]}; // compare printf("gmp_strval: %s\r\n",gmp_strval($Input,36)); printf("BaseConvert: %s\r\n",implode($Result)); /* OUTPUT: gmp_strval: 91h7dixfq6h1 BaseConvert: 91h7dixfq6h1 */ ?> The example shows a familiar result of course, but the idea of this function was so that you can use whatever base you wish, and display entirely your own output to represent any number of choice. Have fun, Nitrogen. ---- Server IP: 69.147.83.197 Probable Submitter: 86.154.84.89 ---- Manual Page -- http://www.php.net/manual/en/ref.gmp.php Edit -- https://master.php.net/note/edit/99788 Del: integrated -- https://master.php.net/note/delete/99788/integrated Del: useless -- https://master.php.net/note/delete/99788/useless Del: bad code -- https://master.php.net/note/delete/99788/bad+code Del: spam -- https://master.php.net/note/delete/99788/spam Del: non-english -- https://master.php.net/note/delete/99788/non-english Del: in docs -- https://master.php.net/note/delete/99788/in+docs Del: other reasons-- https://master.php.net/note/delete/99788 Reject -- https://master.php.net/note/reject/99788 Search -- https://master.php.net/manage/user-notes.php

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