Averaging

[caspergmf]

I am trying to average a string of numbers. I've tryed everything and just don't seem to get it.

After a mysql query I get the result of the of answer choices numbers of a survey. Example:(commas added by me for readability) 52,52,52,52,52,52,52,52,54,54,55,55,55,56,56,56.

I then convert these into a 1 through 4 value which gives me the following result string. Example:(commas added by me for readability)1,1,1,1,1,1,1,1,2,2,3,3,3,4,4,4.

I would like to average this string out which would be 2.0265

 

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[Pikachu2000]

The way you appear to be going about this makes very little sense to me. Why are you not just storing the answers in the database in the correct form (i.e. as 1, 2, 3 or 4) to begin with? Then you could simply SELECT AVG().

[sasa]

try

<?php
        // connect to the database
        $dbLink = mysql_connect("Blah",
                                "Blah",
                                "blah");
        if (!$dbLink) {
                print "Could not connect: ".mysql_error();
                exit(0);
        }

        if (!mysql_select_db("answerchoice", $dbLink)) {
                print "Could not select database: ".mysql_error();
                exit(0);
        }

$query= "SELECT AID FROM answer WHERE (QID = 18) AND UID IN (SELECT UID FROM answer WHERE Answer = 33) ORDER BY AID ASC";
$result = mysql_query($query, $dbLink);
//this query returns data base answer choice numbers (commas added by me for readability) 52,52,52,52,52,52,52,52,54,54,55,55,55,56,56,56
$i = 0;
$tmp = -1;
$ans = array();
while($row = mysql_fetch_array($result)){
    if($row['AID'] > $tmp){
        $i++;
        $tmp = $row['AID'];
        $ans[$i]=0;
    }
   $ans[$i]++;
//$i now holds the answer numbers converted into a 1-4 value (commas added by me for readability)1,1,1,1,1,1,1,1,2,2,3,3,3,4,4,4 I would like to average this string which would be 2.0265
}
foreach ($ans as $v => $c){
    $tot += $v * $c;
    $cnt += $c;
}
if($cnt ) $ave = $tot / $cnt; else $ave = 0;
echo 'average = ',$ave;
?>

[caspergmf]

I think that did it. Thank you sasa.

I believe I will look into Pikachu2000 suggestion for a more streamlined solution.