Use usort:

function cmp($a, $b) {
  if ($a->value == $b->value) {
    return 0;
  } else {
    return $a->value < $b->value : 1 : -1; // reverse order
  }
}

usort($arr, 'cmp');

function cmp($a, $b) {
    return $b->value - $a->value;
}

$ary[0] = usort($ary[0], "cmp");

In order to sort an array based on anything other than simple value or key, you need to use the usort function and supply your own comparison. Comparison functions must be defined such that if $a comes before $b, a positive value is returned and a negative one if $b comes before $a (or zero if they are equal). As you are comparing based on number values and you want a reverse sort, the simplest way of doing this is to subtract the 'value' of $a from the value of $b.

I could be wrong, but I believe I did something like this using asort() (or asort()). It was in a search function, where I needed to sort a two-dimensional array filled with indices and timestamps.

I'm not sure if it will work in your case, and I did it long ago. Maybe it will get you started though, good luck.