apriori algorithm (example - not finished)

<?php
//-------------------
function combination($member,$num){
  $n = count($member);
  //jumlah total kombinasi yang mungkin
  $total = pow(2, $n);
  $list =array();
  //Loop untuk setiap kombinasi yang mungkin
  $k=0;
  for ($i = 0; $i < $total; $i++) {
    $list[$k]=array();
    //Untuk setiap kombinasi, dicek untuk setiap bit
    for ($j = 0; $j < $total; $j++) {
       //apakah data bit $j ada pada bit $i?
        if ((pow(2, $j) & $i)) $list[$k][]=$member[$j];
    }
    if(count($list[$k])==$num){
      //jika jumlah anggota sama dengan jumlah yang diinginkan increment $k
      $k++;
    }else{
      //jika tidak sesuai, hapus array $list[$k]
      unset($list[$k]);
    }
  }
  return $list;
}
//-------------------
function array_composition($list){
  $r=$list[0];
  for($i=1;$i<count($list);$i++){
    $r=array_merge($r,$list[$i]);
  }
  $r=array_values(array_unique($r));
  sort($r);
  return $r;
}
//--------------------
function build_candidate($data,$level){
  $result=combination($data,$level);
  sort($result);
  return $result;
}
//-----------------------
function join_step($source,$data){
  $n=count($data[0]);
  for($i=0;$i<count($data);$i++){
    for($j=0;$j<count($source);$j++){
      $freq=array_intersect($source[$j],$data[$i]);
      $support[$i]=(count($freq)==count($data[$i])?(isset($support[$i])?$support[$i]+1:1):(isset($support[$i])?$support[$i]:0));
    }
  }
  $result=array($data,$support);
  return $result;
}
//-----------------------
function prune_data($data,$min_support){
  $result=array();
  foreach ($data[1] as $key=>$value){
    if($value<=$min_support){
      unset($data[0][$key]);
      unset($data[1][$key]);
    }else{
      $result[0][]=$data[0][$key];
      $result[1][]=$data[1][$key];
    }
  }
  return $result;
}
//-----------------------
function print_transaction($data,$title=NULL){
  echo (isset($title)?"<h2>Transaction for ".$title."</h2>\n":"");
  echo "<div class=\"table\">\n"
      ."<span><div class=\"header\">Trans No</div><div class=\"header\">Items</div></span>\n";
  for($i=0;$i<count($data);$i++){
    echo "<span><div class=\"cell\">".($i+1)."</div><div class=\"cell\">{";
    for($j=0;$j<count($data[$i]);$j++){
      echo ($j==0?"":",").$data[$i][$j];
    }
    echo "}</div></span>\n";
  }
  echo "</div><br>\n";
}
//-----------------------
function print_itemset($data,$level,$title=NULL){
  echo (isset($title)?"<h2>Candidate C-".$level."</h2>\n":"");
  echo "<div class=\"table1\">\n"
      ."<span><div class=\"header\">".$level."-Itemset</div></span>\n";
  for($i=0;$i<count($data);$i++){
    echo "<span><div class=\"cell\">{";
    for($j=0;$j<count($data[$i]);$j++){
      echo ($j==0?"":",").$data[$i][$j];
    }
    echo "}</div></span>\n";
  }
  echo "</div><br>\n";
}
//-----------------------
function print_support($data,$level,$title=NULL){
  echo (isset($title)?"<h2>".$title." ".$level."</h2>\n":"");
  if(!empty($data)){
    echo "<div class=\"table\">\n"
        ."<span><div class=\"header\">".$level."-Itemset</div><div class=\"header\">Count</div></span>\n";
    for($i=0;$i<count($data[0]);$i++){
      echo "<span><div class=\"cell\">{";
      for($j=0;$j<count($data[0][$i]);$j++){
        echo ($j==0?"":",").$data[0][$i][$j];
      }
      echo "}</div><div class=\"cell\">".$data[1][$i]."</div></span>\n";
    }
    echo "</div><br>\n";
  }
}
/***************************/
function apriori($data,$title=NULL){
  echo isset($title)?"<h1>".$title."</h1>":"";
  //echo "<pre>";print_r($data);echo "</pre>";
  print_transaction($data,$title);
  $result[0]=$data;
  $step=1;
  $frequent_item=array(array(),array());
  do{
    $c=array_composition($result[0]);
    //echo "<pre>c-->";print_r($c);echo "</pre>";
    $bl=build_candidate($c,$step);
    //echo "<pre>b_$step-->";print_r($bl);echo "</pre>";
    print_itemset($bl,$step,1);
    $jo=join_step($data,$bl);
    //echo "<pre>j_$step-->";print_r($jo);echo "</pre>";
    print_support($jo,$step,"Join C-");
    $result=prune_data($jo,MIN_SUPPORT);
    $frequent_item[0]=array_merge($frequent_item[0],$result[0]);
    $frequent_item[1]=array_merge($frequent_item[1],$result[1]);
    //echo "<pre>p_$step-->";print_r($result);echo "</pre>";
    print_support($result,$step,"Prune L-");
    $step++;
  }while(!empty($result) && count($result[0])>1);
  //echo "<pre>frequent_item-->";print_r($frequent_item);echo "</pre>";
}
?>
<!doctype html>
<head>
<title>Apriori Algorithm</title>
<style type="text/css">
span.row {
 width:100%;
 display: table-row;
}
div.table{
 border:solid 1px #999;
 width:200px;
 text-align:center;
 padding:2px;
}
div.table1{
 border:solid 1px #999;
 width:100px;
 text-align:center;
 padding:2px;
}
div.header{
 border:solid 1px #999;
 color:#eee;
 background-color:#333;
 font-weight:bold;
 text-align:center;
 width:100px;
 height:20px;
 display: table-cell;
 padding:2px;
}
div.cell {
 border:dashed 1px #eee;
 text-align:center;
 width:100px;
 height:20px;
 display: table-cell;
 padding:2px;
}
</style>
<body>
<div class="container">
<?php
/************************/
define('MIN_SUPPORT',1);
//-------- EXAMPLE -------
$data1=array(
       array('a','c','d'),
       array('b','c','e'),
       array('a','b','c','e'),
       array('b','e')
      );
apriori($data1,'Example #1');
$data2=array(
       array(1,3,4),
       array(2,3,5),
       array(1,2,5),
       array(2,5)
      );
apriori($data2,'Example #2');
?>
</div>
</body>
</html>