Extract value from row in csv and sum it

Question

I'm getting a csv file in input, that is a example of the content:

TIME,Value
2010,77.77046
2010,60.32812
2010Q1,63.33447
2010Q2,61.29888
2010Q3,59.06448
2010Q4,57.62415
2011,60.75586
2011Q1,60.97929
2011Q2,61.36082
2011Q3,59.88779
2011Q4,60.79407

That is the code i use to take the csv, read the content and put it into an array.

if (($handle = fopen("csvExtractTor.csv", "r")) !== FALSE) {
 # Set the parent multidimensional array key to 0.
    $nn = 0;
    while (($data = fgetcsv($handle, 1000, ",")) !== FALSE) {
        # Count the total keys in the row.
        $c = count($data);
        # Populate the multidimensional array.
        for ($x=0;$x<$c;$x++)
        {
            $brim[$nn][$x] = $data[$x];
        }
        $nn++;
    }
    # Close the File.
    fclose($handle);
};

What i need, is to take the values of each quarters​​, for example, 2010Q1, 2010Q2, 2010Q3, 2010Q4, sum it and divided / 4 for the medium and save the operation to a unique value in 2010, into the csv or in a variable. I've tried lots of solutions but none works good. I tried the method strpos(), i was able to read only a value per time, but after that i cannot do other things. Does anyone have an advise to solve my problem?

kind regards

Answer 1

$brim = array();
$years = array();
while (($data = fgetcsv($handle, 1000, ",")) !== FALSE) {
    $brim[] = $data;
    if (preg_match('/^(\d{4})Q(\d)/', $data[0], $match)) {
      $years[$match[1]][$match[2]] = $data[1];
    }
}
foreach ($years as &$year) {
  $year['avg'] = $avg = array_sum($year)/count($year);
}

After this, $years[2010]['avg'] will contain the average of each quarter in 2010.

print_r($years);

Array
(
    [2010] => Array
        (
            [1] => 63.33447
            [2] => 61.29888
            [3] => 59.06448
            [4] => 57.62415
            [avg] => 60.330495
        )

    [2011] => Array
        (
            [1] => 60.97929
            [2] => 61.36082
            [3] => 59.88779
            [4] => 60.79407
            [avg] => 60.7554925
        )

)

Answer 2

This should do the job:

// $csv = file_get_contents('file.csv');
$csv = 'TIME,Value
2010,77.77046
2010,60.32812
2010Q1,63.33447
2010Q2,61.29888
2010Q3,59.06448
2010Q4,57.62415
2011,60.75586
2011Q1,60.97929
2011Q2,61.36082
2011Q3,59.88779
2011Q4,60.79407';
$array = array();

preg_replace_callback('/((\d{4})Q\d),(\d+(?:\.\d+))/', function($matches) use(&$array){
    if(isset($array[$matches[2]])){
        $array[$matches[2]] += ($matches[3]/4);
    }else{
        $array[$matches[2]] = ($matches[3]/4);
    }
    return($matches[1]);
},$csv);
print_r($array);

Output:

Array
(
    [2010] => 60.330495
    [2011] => 60.7554925
)

Online demo.