Re: [PHP] Middle Number

[Rick Widmer]

At 07:05 PM 12/7/02 -0500, Stephen wrote:

Wouldn't this only work for an even ammount of numbers? Like 1, 2, 3, 4 has
4 numbers...

Did you try it? I'd hate to think I've done more work to solve your problem than you have...



Even:

$List = array( 1,2,3,4,5,6 );
$Middle = ( count( $List ) - 1 ) / 2;
2.5 = ( 6 - 1 ) / 2

$median = ( $List[ floor( $Middle ) ] + $List[ ceil( $Middle ) ] ) / 2;

( $List[ 2 ] + $List[ 3 ] ) / 2

3.5 = 3 + 4 /2




Odd:

$List = array( 1,2,3,4,5 );
$Middle = ( count( $List ) - 1 ) / 2;
2 = ( 5 - 1 ) / 2

$median = ( $List[ floor( $Middle ) ] + $List[ ceil( $Middle ) ] ) / 2;

( $List[ 2 ] + $List[ 2 ] ) / 2

3 = ( 3 + 3 ) / 2


It looks like it works to me. For details see:

http://mathforum.org/library/drmath/view/57598.html

>
>
>
>

> At 09:45 PM 12/6/02 -0500, Stephen wrote:
> >How can you find the meadian (or middle number) of a list of numbers? If
> >there is an even amount of numbers, how would I still find it?
>
>
> load the list into an array, in numeric order...
>
> then:
>
> $List = array( 1,2,3,4,5,6 );
>
> $Middle = ( count( $List ) - 1 ) / 2;
>
> $median = ( $List[ floor( $Middle ) ] + $List[ ceil( $Middle ) ] ) / 2;
>


--
PHP General Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php

--
PHP General Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php