Multi-array idea php

There's most likely a more elegant solution, but anyway

<?php
$dataset = [
    [ 'buyer'=>"ACME", 'fees1'=>"100", 'seller'=>"XYZ plc", 'fees2'=>"200", 'item'=>"Bricks" ],
    [ 'buyer'=>"ACME", 'fees1'=>"110", 'seller'=>"XYZ plc", 'fees2'=>"220", 'item'=>"Bricks" ],
    [ 'buyer'=>"XYZ plc", 'fees1'=>"200", 'seller'=>"ACME", 'fees2'=>"300", 'item'=>"Cement" ],
    /* and so on and on */
];

$columns = array_unique(array_column($dataset, 'item'));
//sort($columns);

// create a template with all possible items (as key) and value 0
$template = array_combine(
    $columns,
    array_pad( array(), count($columns), 0)
);


$result = [];
foreach( $dataset as $row ) {
    // if we haven't seen this seller before
    if ( !isset($result[ $row['seller'] ]) ) {
        // create a template with all possible items but each having 0-value
        $result[ $row['seller'] ] = $template;
    }
    // same for buyer
    if ( !isset($result[ $row['buyer'] ]) ) {
        $result[ $row['buyer'] ] = $template;
    }


    // now comes the tricky part
    // remember: $result[$row['seller']] === array('Bricks'=>sumFeeBricks, 'Cemtent'=>sumFeeCement)
    // i.e. $result[$row['seller']]['Cemtent'] += <something> increases sumFeeCement in the array representing the seller in $result
    // $row['item'] tells you which element within $result[$row['seller']] you want to increase
    // ==> $result[$row['seller']][$row['item']] += ....

    // increase sumFee of the sold item by fee2 for the seller
    $result[$row['seller']][ $row['item'] ] += $row['fees2'];

    // increase sumFee of the sold item by fee1 for the buyer
    $result[$row['buyer']][ $row['item'] ] += $row['fees1'];
}
var_export($result);

Just iterate over the array creating a new multidimensional one. No need to translate the givven array directly to the desired output.

I came with an idea of solving it, if you don't have such a function like array_column (i.e. PHP 5.4.10)

<?php
// we assume, the data is organised in such a way: first buyer/seller/whatever then fees1/fees2/etc, item can be at the end or beginning
$a1 = [
    [ 'buyer'=>"ACME", 'fees1'=>"100", 'seller'=>"XYZ plc", 'fees2'=>"200", 'item'=>"Bricks" ],
    [ 'buyer'=>"ACME", 'fees1'=>"110", 'seller'=>"XYZ plc", 'fees2'=>"220", 'item'=>"Bricks" ],
    [ 'buyer'=>"XYZ Plc", 'fees1'=>"200", 'seller'=>"ACME", 'fees2'=>"300", 'item'=>"Cement" ],
    /* and so on and on */
];
function process($obj, $arr){ // we process a single row of $a1
        $data = array(); // first we create an indexed array for storing a single key and its value
        foreach($obj as $key=>$val){
                $key = strtolower($key);
                $val = strtolower($val);
                $data[] = array($key=>$val);
        }
        for($i=0;$i<sizeof($data);$i++){ // we iterate over this array
                $key = array_pop(array_keys($data[$i])); // we've got current key
                $val = $data[$i][$key]; // we've got current value, company
                if(preg_match("/buyer|seller/", $key)){ // if it's seller or buyer or whatever we want just edit
                        $next_key = array_pop(array_keys($data[$i+1])); // we take the next element of $data which is $key=>$value, next key i.e. fees1
                        $next_val = $data[$i+1][$next_key]; // we take its value e.g. 100
                        $arr[$val]+=$next_val; // we put the money for company, and adding them up
                }
        }
        return $arr; // the end of processing a single row of $a1
}
$data = array(); // first we create the data split into items buckets
foreach($a1 as $obj){
        foreach($obj as $key=>$val){
                $key = strtolower($key); // ACME or AcMe, no difference
                $val = strtolower($val);
                if(preg_match("/item/", $key)){
                        $data[$val][] = $obj;
                }
        }
}
print_r($data);
$final = array(); // we store the result for items
foreach($data as $item=>$obj){ // we iterate over items
        $arr = array(); // variable for one item, for next we'll start  from empty array
        foreach($obj as $val){ // we process each row for item
                $arr = process($val, $arr);
        }
        $final[$item] = $arr; // we put processed data to key which is item
}
$total = array(); // we store the total result
foreach($final as $val){
        foreach($val as $key=>$prize){
                    $total[$key]+=$prize; // we add up all money for a single company
        }
}

print_r($final);
print_r($total);
?>