Remember we have copy-on-write in PHP.
Beat this :P :
<?php
$timeArray = array(/* your string time data */);
function timeStamps($ar) {
$stamps = array();
foreach ($ar as $timeString) {
$stamps[strtotime($timeString)] = $timeString;
}
return $stamps;
}
function sortTime(&$ar) {
$timeStampAr = timeStamps($ar);
ksort($timeStampAr); // since the keys are integers, timestamps ksort
would do the right thing
$ar = array_values($timeStampAr);
return $ar; //dont really need this but just in case someone prefers to
use
//it differently or needs a copy
}
sortTime($timeArray);
/* this way the strtotime function is only applied once to each time string
which is probably the most expensive. And ksort uses the sort algorithm that
the PHP core programmers regard as the most efficient. I believe quick sort.
CODE NOT TESTED :P might have minor mistakes but i doubt it :P.*/
?>
Tim-Hinnerk Heuer
http://www.ihostnz.com
Fred Allen - "California is a fine place to live - if you happen to be an
orange."
2009/2/16 Jochem Maas <jochem@xxxxxxxxxxxxx>
> Shawn McKenzie schreef:
> > Shawn McKenzie wrote:
>
> ...
>
> >>> Not tested:
>
> no shit.
>
> >>> function time_sort($a, $b)
> >>> {
> >>> if (strtotime($a) == strtotime($b)) {
> >>> return 0;
> >>> }
> >>> return (strtotime($a) < strtotime($b) ? -1 : 1;
> >>> }
> >>>
> >>> usort($time, "time_sort");
> >>>
> >> Well, I just thought, since the strtotime() uses the current timestamp
> >> to calculate the new timestamp, if you only give it a time then the
> >> returned timestamp is today's date with the new time you passed. If you
> >> had a large array and the callback started at 23:59:59 then you could
> >> end up with some times from the date it started and some from the next
> >> day, which of course would not be sorted correctly with respect to times
> >> only. So, this might be better (not tested):
> >>
>
> ditto (as in nice syntax error).
>
> >>
> >> function time_sort($a, $b)
> >> {
> >> static $now = time();
> >>
> >> if (strtotime($a, $now) == strtotime($b, $now)) {
> >> return 0;
> >> }
> >> return (strtotime($a, $now) < strtotime($b, $now) ? -1 : 1;
> >> }
> >>
> >>
> > Your best bet above.
>
> and G.W.Bush is a socialist.
>
> >
>
> I did a little test, the ultra-fast version offered by McKenzie
> is really great as long as your array of time strings aren't ever
> going to be longer than say 3-4 items (with the caveat that you
> don't use a second argument to strtotime() ... if you do then
> even with 3 items it's substantially slower).
>
> for any reasonable number of items my tests show tedd's version
> pisses on McKenzies from a great height (note that I actually
> optimized Mckenzies variant by halfing the number of calls to
> strtotime()).
>
> I added a third variant, as a sort of control, which runs pretty
> much on par with tedd's version but uses rather less LOC
> (tedd you might like it as a little example of using array_multisort(),
> i.e. a way of avoiding writing the double foreach loop in this case)
>
> tedd's variant: sortTime1()
> McKenzie's variant: sortTime2()
> my variant: sortTime3()
>
> sample output from one of my test runs:
> ===============================================================
> ===============================================================
> No. of array items = 3, no of iterations = 10000
> -------
> timeSort1() ran for 1.306011 seconds
> timeSort2() ran for 1.337358 seconds
> timeSort3() ran for 1.742724 seconds
>
> No. of array items = 6, no of iterations = 10000
> -------
> timeSort1() ran for 2.647697 seconds
> timeSort2() ran for 2.475791 seconds
> timeSort3() ran for 7.268916 seconds
>
> No. of array items = 9, no of iterations = 10000
> -------
> timeSort1() ran for 3.891894 seconds
> timeSort2() ran for 3.960463 seconds
> timeSort3() ran for 18.440713 seconds
>
>
>
>
> the test script:
> ===============================================================
> ===============================================================
> <?php
> // TEST
> ini_set("date.timezone", "Europe/Amsterdam");
>
> $iter = 10000;
> $time = array(
> array("1:30pm", "7:30am", "12:30pm"),
> array("1:30pm", "7:30am", "12:30pm", "4:45pm", "8:15am", "11:00pm"),
> array("1:30pm", "7:30am", "12:30pm", "4:45pm", "8:15am", "11:00pm",
> "4:30am", "6:45am", "12:00pm"),
> );
>
> foreach ($time as $t)
> testIt($t, $iter);
>
>
> // FUNCS
>
> function sortTime1($in_times)
> {
> $time = array();
> foreach ($in_times as $t)
> $time[] = strtotime($t);
>
> sort($time);
>
> $sort_time = array();
> foreach ($time as $t)
> $sort_time[] = date("g:ia", $t);
>
> return $sort_time;
> }
>
> function timeSort2($in)
> {
> static $time = null;
>
> if (!$time)
> $time = time();
>
> $now = array_fill(0, count($in), $time);
> $out = array_map("strtotime", $in, $now);
> array_multisort($out, SORT_NUMERIC, SORT_ASC, $in);
>
> return $in;
> }
>
> function timeSort3($a, $b)
> {
> static $now = null;
>
> if (!$now)
> $now = time();
>
> $a = strtotime($a, $now);
> $b = strtotime($b, $now);
> if ($a == $b)
> return 0;
>
> return $a < $b ? -1 : 1;
> }
>
> function testIt($time, $iter)
> {
> echo "\nNo. of array items = ", count($time), ", no of iterations =
> $iter\n-------\n";
>
> $s = microtime(true);
> for ($i = 0; $i < $iter; $i++)
> timeSort2($time);
> $e = microtime(true);
> echo "timeSort1() ran for ".round($e-$s, 6)." seconds \n";
>
> $s = microtime(true);
> for ($i = 0; $i < $iter; $i++)
> timeSort2($time);
> $e = microtime(true);
> echo "timeSort2() ran for ".round($e-$s, 6)." seconds \n";
>
> $s = microtime(true);
> for ($i = 0; $i < $iter; $i++)
> usort($time, "timeSort3");
> $e = microtime(true);
> echo "timeSort3() ran for ".round($e-$s, 6)." seconds \n";
> }
>
> --
> PHP General Mailing List (http://www.php.net/)
> To unsubscribe, visit: http://www.php.net/unsub.php
>
>
