合并二维数组，并计算重复字段的平均值

<?php
$arrs = Array ( 
    Array ( 'rname' => '小麦', 'm1'=> 12.00 ,'m2'=> 33,'qq'=> 33  ) ,
    Array ( 'rname' => '小麦', 'm1' => 23.00,'m2'=> 44,'qq'=> 11 ) ,
    Array ( 'rname' => 'ccc', 'm1' => 11,'m2'=> 22,'qq'=> 12 ) 
);

//计算出重复字段出现的次数
$b=array();
foreach($arrs as $v){
    $b[]=$v['rname'];
}
$c=array_unique($b);
foreach($c as $v){
    $n=0;
    foreach($arrs as $t){
        if($v==$t['rname'])
            $n++;
    }
    $d[]['nn']=$n;
    
}

//合并数组中重复的值，并进行加计算
$tmpval=array();
$data=array();
$i=0;
//遍历原数据
foreach($arrs as $key=>$arr){
    
    if(!empty($tmpval) && array_key_exists($arr['rname'],$tmpval)){
        //存在
        $key=$tmpval[$arr['rname']];
       
        $data[$key]['m1']+=$arr['m1'];
        
        $data[$key]['m2']+=$arr['m2'];        
    }else{
        //不存在
        $tmpval[$arr['rname']]=$i;
        $data[$i++]=$arr;
    }
}

//把2个二维数组合并成一个二维数组
$zuizhong = array();
foreach($data as $k=>$r){
    $zuizhong[] = array_merge($r,$d[$k]);
}

//计算出平均值
$datas = array();
foreach($zuizhong as $key=>$arr){    
    $datas[$key]['rname'] = $arr['rname'];
    $datas[$key]['m1'] = $arr['m1']/$arr['nn'];    
    $datas[$key]['m2'] = $arr['m2']/$arr['nn'];
} 

echo "<pre>";
print_r($d);
print_r($data); 
print_r($zuizhong); 
print_r($datas); 

http://www.cnblogs.com/losesea/archive/2013/06/14/3134900.html