array sort extended

<?php
$arr= array("2" =>"ayam", "3" =>"ikan","4" =>"katak", "5" =>"burung", "8" => "itik", "9" => "rusa","10" => "sapi", "11" => "kerbau", "13" => "kancil", "14" => "buaya", "15" => "semut", "17" =>"lebah", "18" => "cacing","19" => "ulat", "20" => "lalat", "21" => "nyamuk", "26" => "kutu");
$min=4;
function sort_grouping($data,$limit){
$n=0;
foreach($data as $k=>$v){
$n=($n==0?$k-1:$n);
if(($k-$n)==1){
$temp_arr[$k]=$v;
}else{
if(count($temp_arr)>=$limit){
$new_arr[]=$temp_arr;
}
unset($temp_arr);
$temp_arr[$k]=$v;
}
$n=$k;
}
return $new_arr;
}
echo "<pre>";
print_r(sort_grouping($arr,4));
echo "</pre>";
?>