Comments on: Sorting PHP arrays with substrings http://www.codediesel.com/php/sorting-arrays-with-value-substrings-in-php/ /* PHP & MySQL Journal */ Fri, 27 Jan 2012 16:39:42 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: eleg http://www.codediesel.com/php/sorting-arrays-with-value-substrings-in-php/comment-page-1/#comment-1638 eleg Mon, 18 Jan 2010 22:31:05 +0000 http://www.codediesel.com/?p=2141#comment-1638 please strip the line: <code> $b.($b?":":"_") .str_pad($a,10,"_",STR_PAD_LEFT);'); </code> >:-[ please strip the line:


$b.($b?":":"_")
.str_pad($a,10,"_",STR_PAD_LEFT);');

>:-[

]]> By: eleg http://www.codediesel.com/php/sorting-arrays-with-value-substrings-in-php/comment-page-1/#comment-1637 eleg Mon, 18 Jan 2010 22:28:12 +0000 http://www.codediesel.com/?p=2141#comment-1637 oops (^Z) corrected to: <code> $max = array_reduce($valeurs,create_function('$a,$b', 'return (strlen($a)<strlen($b)?$b:$a);')); $max=strlen($max); $f1 = create_function('$v', 'global $max; list($a,$b)=explode(":",$v);return $b.($b?":":"_").str_pad($a,$max,"_",STR_PAD_LEFT);'); $b.($b?":":"_").str_pad($a,10,"_",STR_PAD_LEFT);'); $f2 = create_function('$v', 'list($a,$b)=explode(":",$v);return ltrim($b,"_").($b?":".$a:ltrim($a,"_"));'); $valeurs = array_map($f1,$valeurs); sort($valeurs); $valeurs = array_map($f2,$valeurs); </code> -> 4.84191417694 (still better, probably not optimal) oops (^Z)

corrected to:

$max = array_reduce($valeurs,create_function('$a,$b', 'return (strlen($a)<strlen($b)?$b:$a);'));
$max=strlen($max);
$f1 = create_function('$v', 'global $max; list($a,$b)=explode(":",$v);return $b.($b?":":"_").str_pad($a,$max,"_",STR_PAD_LEFT);');
$b.($b?":":"_").str_pad($a,10,"_",STR_PAD_LEFT);');
$f2 = create_function('$v', 'list($a,$b)=explode(":",$v);return ltrim($b,"_").($b?":".$a:ltrim($a,"_"));');

$valeurs = array_map($f1,$valeurs);

sort($valeurs);

$valeurs = array_map($f2,$valeurs);

-> 4.84191417694 (still better, probably not optimal)

]]> By: eleg http://www.codediesel.com/php/sorting-arrays-with-value-substrings-in-php/comment-page-1/#comment-1636 eleg Mon, 18 Jan 2010 21:57:52 +0000 http://www.codediesel.com/?p=2141#comment-1636 <code> $f1 = create_function('$v', 'list($a,$b)=explode(":",$v);return $b.($b?":":"_").$a;'); $f2 = create_function('$v', 'list($a,$b)=explode(":",$v);return $b.($b?":".$a:ltrim($a,"_"));'); $valeurs = array_map($f,$valeurs); sort($valeurs); $valeurs = array_map($f,$valeurs); </code> array of 3000 items : yours = 1.96446013451 this = 0.0130748748779 ~30000 items : 26.4119880199 0.182013988495 seems coherent results. I don't even know why I have imagined such a solution! or why it looks like more efficient!
$f1 = create_function('$v', 'list($a,$b)=explode(":",$v);return $b.($b?":":"_").$a;');
$f2 = create_function('$v', 'list($a,$b)=explode(":",$v);return $b.($b?":".$a:ltrim($a,"_"));');

$valeurs = array_map($f,$valeurs);

sort($valeurs);

$valeurs = array_map($f,$valeurs);

array of 3000 items :
yours = 1.96446013451
this = 0.0130748748779

~30000 items :
26.4119880199
0.182013988495

seems coherent results.

I don’t even know why I have imagined such a solution! or why it looks like more efficient!

]]> By: jeichhor http://www.codediesel.com/php/sorting-arrays-with-value-substrings-in-php/comment-page-1/#comment-1562 jeichhor Wed, 16 Dec 2009 21:51:17 +0000 http://www.codediesel.com/?p=2141#comment-1562 if you have plenty of RAM you could give this a try: <code> <?php $values = array("66345:CDF", "61179:HGT", "64146:ABA", "68768:BNG", "68015:ZCZ", "80231:LPO", "64146:QWP", "68736:HHB", "86801:MNV", "80178:OIU", "80178:ASE", "88178:BRT", "801782OIU", "801378ASE", "881578BRT"); //get more values for longer experience for ($z1=0;$z1sizeof($values) ,"time to beat"=>$t1-$t0 ,"time took"=>$t2-$t1 ) ); ?> 22.43:je@8@booster:~ $ /usr/local/php5/bin/php /var/www/test.php array(3) { ["number of items to sort:"]=> int(15360) ["time to beat"]=> float(6.2945919036865) ["time took"]=> float(2.0644869804382) } 22.47:je@8@booster:~ </code> if you have plenty of RAM you could give this a try:

<?php

$values = array("66345:CDF", "61179:HGT", "64146:ABA",
"68768:BNG", "68015:ZCZ", "80231:LPO",
"64146:QWP", "68736:HHB", "86801:MNV",
"80178:OIU", "80178:ASE", "88178:BRT",
"801782OIU", "801378ASE", "881578BRT");

//get more values for longer experience
for ($z1=0;$z1sizeof($values)
,"time to beat"=>$t1-$t0
,"time took"=>$t2-$t1
) );

?>

22.43:je@8@booster:~
$ /usr/local/php5/bin/php /var/www/test.php
array(3) {
["number of items to sort:"]=>
int(15360)
["time to beat"]=>
float(6.2945919036865)
["time took"]=>
float(2.0644869804382)
}
22.47:je@8@booster:~

]]>