[RESOLVED] X Y Sorting (Multidimensional Array)

[Kudose]

Hello all. I am trying to sort a multidimensional array based on 2 criteria. This is a new one for me, so forgive me if it's something simple.

I have a 2D array with 3 indices. 0 is the y coordinate, 1 is x, and 2 is reserved for something else.

I need to sort on indice 1, then 0. I need to preserve the first sorts place.

i.e.

    [9] => Array
        (
            [0] => 625
            [1] => 1410
            [2] => 64_2000_BMW_740_c.jpg
        )
    [8] => Array
        (
            [0] => 625
            [1] => 1502
            [2] => 69_2000_BMW_740_k.jpg
        )

[10] => Array
    (
        [0] => 795
        [1] => 1502
        [2] => 70_2000_BMW_740_i.jpg
    )

Here is the code I am using from the web:

function compare($x, $y){
         if ( $x[1] == $y[1] )
          return 0;
         else if ( $x[1] < $y[1] )
          return -1;
         else
          return 1;
        }
/** get images array (in "y x" format **/
        $images = $_POST['images'];
        /** explode images array into y x cords **/
        foreach($images as $key => $value){
          $images[$key] = explode("\x20", $value);
          /** put image name into 3rd element **/
          $images[$key][] = $listingImages[$key];
        }

    /** sort values by x, then y **/
    /** x = $images[1] & y = $images[0] **/
    usort($images, 'compare');

    echo '<pre>'; print_r($images); echo '</pre>';

Obvisouly, this sorts based on X and nothing else.

Any help would be appreciated.

[Installer]

Something like this should do it:

foreach ($array as $key => $val) {
    $tmp_0[$key] = $val[0];
    $tmp_1[$key] = $val[1];
}
array_multisort($tmp_1, SORT_ASC, $tmp_0, SORT_ASC, $array);

[Kudose]

Perfect. Didn't even know that function existed.

Thanks much. 🙂

[Weedpacket]

As an aside, the usort() method still works: compare index 1 of the two elements. If they compare different you have their relative ordering and can return it; if they compare the same, then compare index 0. (It's like comparing dates: if the years are different it's obvious which one comes first. If the years are the same then you look at the months. If both dates refer to the same month, then you look to see if they refer to the same day....)