array_sum

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didikdwi at gmail dot com
18-Jul-2007 01:48


This is a simple approach to subtract array, both indexed and associative.



  function array_sub($arr) {

    if (!is_array($arr) || count($arr) == 0) {

      return false;

    } else {

      // get first element

      $base = array_shift($arr);



      if (count($arr) == 1) {

        // If only one element, return its

        return $base;

      }



      foreach ($arr as $val) {

        $base -= $val;

      }



      return $base;

    }

  }



// example

$arr1 = array(3, 2, 3);

echo array_sub($arr1);   // Output: -2

$arr2 = array(3.5, 2, 3);

echo array_sub($arr2);   // Output: -1.5

$arr3 = array('a' => 3, 'b' => 2, 'c' => 3);

echo array_sub($arr3);   // Output: -2

herenvardo at gmail dot com
24-Nov-2006 11:28


I'm not sure if something similar already exists, but I needed it so I made it:

<?php

  /* Performs a pitagoric sum of the elements in $arr

   The pitagoric sum of a set of values is the square root of

   the sum of the sqare power of each value. So, for a, b, c

   it's sqrt(a^2 + b^2 + c^2) */

  /* If any element of $arr is an array itself, the array_sum

   will be used. Alternatively, the values could be used by

   recursion. Returns the integer part (floor) */

  function array_pitag_sum($arr) {

    if(is_array($arr) {

      $ret = 0;

      foreach($arr as $i) {

        if(is_array($i)) {

          $s = array_sum($i);

          $ret += $s*$s;

        } else {

          $ret += $i*$i;

        }

      }

      return floor(sqrt($ret));

    } else {

      return $arr;

    }

  }

?>

Tobias Schlemmer
28-Jul-2006 06:41


<?php

$array1 = array('1'=>'1','2'=>'2','3'=>'3');

$array2 = array(          '2'=>'1','3'=>'2','4'=>'3');

$array3 = array(                  '3'=>'1','4'=>'2','5'=>'3');

$array  = array_sum_values( $array1, $array2, $array3 );

print_r($array);



/**

 * Sums the values of the arrays be there keys (PHP 4, PHP 5) 

 * array array_sum_values ( array array1 [, array array2 [, array ...]] )

 */

function array_sum_values() {

    $return = array();

    $intArgs = func_num_args();

    $arrArgs = func_get_args();

    if($intArgs < 1) trigger_error('Warning: Wrong parameter count for array_sum_values()', E_USER_WARNING);

    

    foreach($arrArgs as $arrItem) {

        if(!is_array($arrItem)) trigger_error('Warning: Wrong parameter values for array_sum_values()', E_USER_WARNING);

        foreach($arrItem as $k => $v) {

            $return[$k] += $v;

        }

    }

    return $return;

}

/* result:

Array

(

    [1] => 1

    [2] => 3

    [3] => 6

    [4] => 5

    [5] => 3

)

*/

?>

jodymickey at yahoo dot com
01-Jun-2006 03:23


In reference to KageKonjou's array_mode function...



If you only want to know the value in the array that occurs most (and not the number of times it actually occured), you can use this short function.  It also suffers from the same problem in that if there is more than one mode, it will return only one.

<?php

    function array_mode($array)

    {

        if(!is_array($array)) return false;

        asort(array_count_values($array));

        return array_pop($array);

    }

?>

Moslehi[atsign]Gmail[dot]com
17-Mar-2006 11:13


A simple example for numeric values :



<?PHP 



function array_average($arr){

$sum = array_sum($arr);

$num = sizeof($arr);

echo $sum/$num;

}



$myarray = array(1,2,3,4);

array_average($myarray); // displays 2.5 as average of 1,2,3,4



?>



[Arash Moslehi]

darianlassan at yahoo dot de
04-Nov-2005 11:57


function array_avg(&$array)

{

  //**

    returns the average value of all array-values

    or false if no values in array (or not an array)

  **//



  if (!is_array($array) || count($array)==0) 

    return false;

  else

    return array_sum($array)/count($array);

} // array_avg()



Please add this function to PHP.

mroach at mroach dot com
27-Sep-2005 08:06


I ran into a situation where I only wanted to sum elements of an array for certain keys. For that, I wrote this function



<?



function array_sum_by_key()

{

    $args = func_get_args();

    

    $arr = array_shift($args);

            

    $to_sum = is_array($args[0]) ? $args[0] : $args;

    

    $sum = 0;



    foreach ( $arr as $k=>$v ) {

        if ( in_array($k, $to_sum) ) {

            $sum += $v;

        }

    }

    

    return $sum;

}



$arr = array (

    'dog' => 1,

    'cat' => 2,

    'rat' => 4,

    'mat' => 8,

    'bat' => 16

);



echo array_sum_by_key($arr, 'dog', 'mat');



// Result: 9



?>



Alternatively, you can pass the keys to sum as an array



<?



$to_sum = array('dog', 'bat');



echo array_sum_by_key($arr, $to_sum);



// Result: 17



?>

KageKonjou at GMail dot com
12-Aug-2005 04:22


Not sure where else to put this, but I added something that determines the most commonly occuring item in an array.  Known Bugs: It will always return the first value if no mode are found, and the first mode found if more are found of same or lesser count.



<?php

function array_mode($array) {

 $count = array();

 foreach ($array as $item) {

  $count[$item]++;

 }

 $mostcommon = "";

 $iter = 0;

 foreach ($count as $k => $v) {

  if ($v > $iter) {

   $mostcommon = $k;

   $iter = $v;

  }

 }

 return array("mode" => $mostcommon, "count" => $count[$mostcommon]);

}

?>

punchto at hotmail dot com
16-Mar-2005 03:06


Microsoft Excel - SUMIF()



function sumif($array,$criteria,$sum_array){ 

  if(is_array($array) && is_array($sum_array) && trim($criteria)!= ""){ 

    $array_count = (count($array) < count($sum_array)) ? count($array):count($sum_array);

    for($i=0;$i<$array_count;$i++){

      if(ereg("^<",$criteria)){

        $value = ereg_replace("^<","",$criteria);

        $result += $array[$i] < $value ? $sum_array[$i]:0; 

      }

      elseif(ereg("^>",$criteria)){ 

        $value = ereg_replace("^>","",$criteria);

        $result += $array[$i] > $value ? $sum_array[$i]:0;

      }

      else{

        $value = $criteria;

        $result += $array[$i] == $value ? $sum_array[$i]:0;

      }

      

    }

    return $result ? $result:0;

  }

}

adam at laural dot com dot au
02-Mar-2005 12:37


Here's a function to return the sum of a portion of an array:



function array_partial_sum($array, $start, $length){

    $new_array = array_slice($array, $start, $length);

    return array_sum($new_array);

}



$array = array(1, 2, 3, 4, 5);

print array_partial_sum($array, 0, 3);  // prints 6

ncheung at maine dot rr dot com
08-Feb-2005 02:02


For clarity, array indices containing boolean values such as TRUE and FALSE are added up as though they are 1 and 0 respectively.

info at sgonda dot de
07-Dec-2003 11:54


Don't use number_format() before array_sum()...it won't work correctly, if you have a summary...

mucello NOO SPAM @ weatherimages dOt org
22-Oct-2003 10:44


If you want to find the AVERAGE of the values in your array, use the sum and count functions together.  For example, let's say your array is $foo and you want the average...





<?php


$average_of_foo = array_sum($foo) / count($foo);


?>

mcrm at NOTNEEDIT dot freemal dot it
13-Aug-2003 04:40


Hi people, if someone is searching a function that works also with multimension array, i suggest this :





<?php


function cw_array_count($a) {


  if(!is_array($a)) return $a;


  foreach($a as $key=>$value) 


     $totale += cw_array_count($value);


  return $totale;


}





$a[0][E][PS][P][a1]=1;


$a[0][E][PS][P][a2]=2;


$a[0][E][PJ][P][a2]=2;


$a[1][E][PS][E][a3]=3;





echo cw_array_count($a[0]);


// or


echo cw_array_count($a[0][E]);


?>





Bye, Bye.


R.Martina

drverieevil at REMOVEMEasenne dot org
30-Jul-2003 10:14


If some array elements arent integers, function will change them to integers (content of array will not change) type and then sum them.



Example:

<?php

$foo[] = "12";

$foo[] = 10;

$foo[] = "bar";

$foo[] = "summer";

echo array_sum ($foo); //same as echo "22";

?>

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