How to make an average of array values

Question

I have a database with multiple records. It is structured like this:

["data"]=>
  array(5) {
   [1]=>
    [2]=>
      array(11) {
        [0]=>
        string(1) "0"
        [1]=>
        string(8) "25000000"
        [2]=>
        string(3) "day"
        [3]=>
        string(5) "0.00%"
        [4]=>
        string(9) "404049904"
        [5]=>
        string(1) "0"
        [6]=>
        string(5) "0.00%"
        [7]=>
        string(1) "0"
        [8]=>
        string(1) "0"
        [9]=>
        string(1) "0"
        [10]=>
        string(3) "0.0"
      }

I need to fetch the 8th record and I do this by using

public static function($data)
        {
            $array = [];
            $path = $data->data[2];
            foreach($path as $key => $item)
                if($key > 1)
            {
                $array[] = [$item->data[8]];
            }

            return json_encode($array);
        }

This foreach takes all the 8th values from the array but I need to display a single number which is the average of all the 8th values. How can I do this?

the problem is, you put this $item->data[8]; into a new array. Put just $array[] = $item->data[8]; and the you can use the answers. — vaso123
– vaso123, Commented Jun 3, 2016 at 9:52

Dale · Accepted Answer · 2016-06-03 09:51:28Z

1

Once you've got your array containing all your data, simple sum the array and then divide by the size of the array.. something along these lines

$average = (array_sum($array) / count($array));

Of course you may want to check for count($array) being 0;

answered Jun 3, 2016 at 9:51

Dale

10.5k23 silver badges34 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

vaso123 Over a year ago

no good. because of: [$item->data[8]]; add element as array, not a value. array_sum will be 0.

Dale Over a year ago

Yes I'm just trying to impart the idea :)

vaso123 · Accepted Answer · 2016-06-03 09:57:43Z

0

Because you put your value into a new array, you can not use array_sum to sum the values, so you should store it.

$sum = 0;
foreach($path as $key => $item)
   if($key > 1)   {
      $array[] = [$item->data[8]];
      $sum += $item->data[8];
   }
}
$avg = ($sum / count($array); //the average
var_dump($avg);

If is it possible, just put it as a value:

$array[] = $item->data[8];  //no wrapping []

In this case, you can use $avg = array_sum($array) / count($array);

answered Jun 3, 2016 at 9:57

vaso123

12.4k4 gold badges38 silver badges68 bronze badges

Comments

Ali Zia · Accepted Answer · 2016-06-03 09:52:45Z

0

if (count($array)>0){
    $avg = array_sum($array) / count($array);
}

answered Jun 3, 2016 at 9:52

Ali Zia

3,8855 gold badges34 silver badges83 bronze badges

1 Comment

vaso123 Over a year ago

no good. because of: [$item->data[8]]; add element as array, not a value.

PieterLourens · Accepted Answer · 2016-06-03 10:07:54Z

0

I would personally do those calculations in the database before the data gets to your PHP script itself. See AVG().

If you can't for some reason use that I would output those values into a flat array and then just calculate the average. So something like :

function getAverage($data) {
  $flatArray = array();
  foreach ($data as $row) {
    if (!empty($row->8)) {
        $flatArray[] = $row->8;
    }
  }
  return (array_sum($flatArray)/count($flatArray));
}

EDIT: Moved to Object traversing on the data row, sorry, missed that initially and thought it was an array in all the nests.

edited Jun 3, 2016 at 10:07

answered Jun 3, 2016 at 9:58

PieterLourens

6212 bronze badges

Comments

Poiz · Accepted Answer · 2016-06-03 11:13:59Z

Since you have a loop within your static Method; why not do the calculation therein and return it or add it to the JSON Data if You need your Data in JSON Format? Here's what's implied by the above:

        public static function getAverageSum($data) {
            $array      = [];
            $path       = $data->data[2];
            $sumTotal   = 0.00;     //<== YOU COULD JUST SUM IT DIRECTLY WITHOUT USING AN ARRAY
            foreach($path as $key => $item) {
                if ($key > 1) {
                    $array[]    = $item->data[8];
                    $sumTotal  += floatval($item->data[8]);
                }
            }

            // IF YOU ARE ONLY INTERESTED IN THE AVERAGE SUM YOU COULD EVEN ADD IT IT TO THE $array AS AN EXTRA KEY
            // LIKE SO:
            $arrLen             = count($array);
            $array['avgSum']    = $sumTotal/$arrLen;


            // IF YOU NEED YOUR DATA IN JSON... THEN RETURN THE JSON ENCODED DATA WITH SUM AS PART OF THE DATA.
            // YOU'D HAVE NO NEED FOR array_sum() SINCE YOU DID YOUR PREP-WORK ALREADY...
            return json_encode($array);

            // ALTERNATIVELY; IF ALL YOU NEED IS JUST THE AVERAGE SUM; YOU COULD AS WELL DIRECTLY RETURN $sumTotal/$arrLen
            return ($sumTotal/$arrLen);

        }

Collectives™ on Stack Overflow

How to make an average of array values

5 Answers 5

2 Comments

Comments

1 Comment

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

2 Comments

Comments

1 Comment

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related