PHP - merging 2D array by keys - php

Question

How can I merge these array together?
Array
(
[0] => Array
(
[type] => Person
[relevance] => 0.700000
[count] => 300
[text] => Chris
)
)
Array
(
[0] => Array
(
[type] => Person
[relevance] => 0.900000
[count] => 400
[text] => Chris
)
[1] => Array
(
[type] => Person
[relevance] => 0.500000
[count] => 200
[text] => Tom
)
)
or array like this:
Array
(
[0] => Array
(
[type] => Person
[relevance] => 0.700000
[count] => 300
[text] => Chris
)
[1] => Array
(
[type] => Person
[relevance] => 0.900000
[count] => 400
[text] => Chris
)
[2] => Array
(
[type] => Person
[relevance] => 0.500000
[count] => 200
[text] => Tom
)
)
The expected result is:
Array
(
[0] => Array
(
[type] => Person
[relevance] => 0.800000
[count] => 700
[text] => Chris
)
[1] => Array
(
[type] => Person
[relevance] => 0.500000
[count] => 200
[text] => Tom
)
)
[relevance] value is an average number
[count] value is an incremental number
The merging of these array should base on [text] value.
How can I do this with php in a fast way?
Thanks for helping.

Answer 1

If this is the array
$array = Array(
Array(
'type' => 'Person',
'relevance' => .7,
'count' => 300,
'text' => 'Chris'
),
Array(
'type' => 'Person',
'relevance' => .9,
'count' => 400,
'text' => 'Chris'
),
Array(
'type' => 'Person',
'relevance' => .5,
'count' => 200,
'text' => 'Tom'
),
);
then:
$tmp = Array();
foreach($array as $obj) {
if(!isset($tmp[$obj['text']])) {
$tmp[$obj['text']] = array_merge(Array('total_count'=>1),$obj);
continue;
}
$tmp[$obj['text']]['count'] += $obj['count'];
$tmp[$obj['text']]['relevance'] += $obj['relevance'];
$tmp[$obj['text']]['total_count']++; // useful for average calculation
}
$result = Array();
foreach($tmp as $key=>$obj) {
$obj['relevance'] = $obj['relevance']/$obj['total_count'];
unset($obj['total_count']); // useless now
$result[] = $obj;
}
print_r($result);

Answer 2

Something like this maybe:
$newArray = array();
foreach ($oldArray as $item) {
if (!array_key_exists($item['text'], $newArray)) {
$newArray[$item['text']] = $item;
$newArray[$item['relevance_values']] = array();
} else {
$newArray[$item['text']]['count'] += $item['count'];
$newArray[$item['relevance_values']][] = $item['relevance'];
}
}
foreach ($newArray as $item) {
$relevance = 0;
foreach ($item['relevance_values'] as $value) {
$relevance += $value;
}
$item['relevance'] = $relevance / count($item['relevance_values']);
}

Answer 3

Try this:
function mergeOnText($array){
$results = array();
foreach($array as $person){
$found = -1;
foreach($results as $i => $res)
if($res['text'] == $person['text']){
$found = $i;
break;
}
if($found > -1){
$results[$found]['relevance'][] = $person['relevance'];
$results[$found]['count'] += $person['count'];
} else {
$results[] = $person;
}
}
foreach($results as $i => $res)
$results[$i]['relevance'] = array_sum($res['relevance']) / count($res['relevance']);
return $results;
}