[Resolved] Need some help

xarnet

I was just wondering how I would go about displaying an average of three different variables. Like say for example I have 3 fields with 3 numbers (all are out of 10), so say like 8,9,8. How would I go about having it calculated and then having the average displayed in the form of 0.0 ?? So for the 8,9,8 it would display: 8.3

Once again any help on this issue would be much appreciated.

BeastRider

So...

Are you wondering about:

a) the arithmetic aspect of this problem?
b) the html aspect of this problem?
c) the php aspect of this problem?
d) the mysql aspect of this problem?

It just doesn't seem like much of a problem.

xarnet

Well the three different fiels will be from my database so I have no problem having them pulled from the database:
$data->field1
$data->field2
$data->field3

But I need the avarage to be $overall, but I just don't know how to do it (in terms of the PHP). So yes my issue is a PHP problem nothing else really. Well I guess it's also partially an arithmetic problem, although I know to get the average you need to add the three fields and divide by the total number of fields(3).

xarnet

I did the following:

<?php
$overall = (($data->field1 + $data->field2 + $data->field3)/ 3)
echo $overall
?>

And it seemed to work just great. Although I now run into another problem. You see there will be around 2-10 rows and I want to also be able to have an average between all the $overall. Is there anyway for this to be accomplished?

leatherback

Hi,

You could do something like

select statement

$total = 0;
$i = 0;

while ($row = mysql_fetch_array($result))
{
$total = $total + $row[value];
i = i+1;
}

$average = $total / $i;

echo $average;

xarnet

So how would I got about implementing that into my code:

<?php
$query = @mysql_query("SELECT * FROM animereview WHERE animeid = '$id' ORDER BY id");
while ($data = @mysql_fetch_object($query)) {
?>
<table width="100%" cellpadding="1" cellspacing="0" border="0" id="con">
<tr>
<td width="90%"><b>Field 2:</b></td>
<td width="10%"><?PHP echo $data->field2;?></td>
</tr>
<tr>
<td width="90%"><b>Field 3:</b></td>
<td width="10%"><?PHP echo $data->field3;?></td>
</tr>
<tr>
<td width="90%"><b>Overall:</b></td>
<td width="10%"><?PHP
$overall = (($data->field1 + $data->field2 + $data->field3)/ 3);
echo $overall;
?>/td>
</tr>
</table>
<br>
<?php
}
?>

Thanks again ^_

laserlight

Why not try?
For 1 decimal place,

<?php
$query = @mysql_query("SELECT * FROM animereview WHERE animeid = '$id' ORDER BY id");
while ($data = @mysql_fetch_object($query)) {
?>
<table width="100%" cellpadding="1" cellspacing="0" border="0" id="con">
<tr>
<td width="90%"><b>Field 2:</b></td>
<td width="10%"><?php echo $data->field2; ?></td>
</tr>
<tr>
<td width="90%"><b>Field 3:</b></td>
<td width="10%"><?php echo $data->field3; ?></td>
</tr>
<tr>
<td width="90%"><b>Overall:</b></td>
<td width="10%"><?php
	$overall = $data->field1 + $data->field2 + $data->field3;
	echo round($overall / 3, 1);
?></td>
</tr>
</table>
<br>
<?php
}
?>

xarnet

Ok I will try that, but say for example I had 4 rows, how would I make it so that all the $overall would be added together and then divied by the amount of rows. Also note that the amount of rows will vary. Once again thanks in advance.

leatherback

Hi,

What are your rows / fields etc?

A row = a row in a database? Or are they actually colums in your database?

If they are colums in a specific row (So individual field of that record) you need a different setup then when you look at one colum, for different records.

xarnet

Basically it's a review system, where each row is a different review by a different staff member. In each row there will be the three colulmns (fields) that will go to make each person's overall score for the particular show. The code I was currently using works fine for that, but what I need is to have all the overall scores from the reviewers averaged for the a new Overall score, so say the overall for the first row came to 9, the 2nd row came to 10 and the third 9, I would want a script to calculate the Total Overall as 9.3 ((9+10+9)/3).

laserlight

Well, if you mean columns, since your columns arent dynamically written to the page, you can easily modify the code when you modidy the columns.

laserlight

You could set a $total = 0 outside the while loop
then use $total += $overall within the loop
after the loop exits, divide $total by the result of mysql_num_rows($query)

of course it would probably be good practice to check that the query returns at least 1 result, otherwise you'll get a division by 0 runtime error.

leatherback

Hi Xarnet,

sorry. I do not see the problem. You can calculate the average per row? And now you need the average of multiple rows? Why not use the code I suggested above?

I am a bit confused with your used of field1, field2, field3 however. It suggests you are using colums instead of rows..?

xarnet

Ok the 3 fiels are columns, Animation, Plot and Characters, now the poeple give a score out of ten for each of these then the average of the scores are put together to get their overall score of the Anime. Now if only one person reviews teh anime there will only be one row, however if say 3 people review it there will be 3. So I wanted to know a way to figure out the total average, like say the first reviews average is 10, the 2nd was 9 and the third was 9 then I would want the total Overall score to be 9.3.

Now my problem is more the fact that I am very new to PHP and thus I do not understand how to implement the script you are talking about to get what I need accomplished. (that being implemented into the script I currently have below):

<?php
$query = @mysql_query("SELECT * FROM animereview WHERE animeid = '$id' ORDER BY id");
while ($data = @mysql_fetch_object($query)) {
?>
<table width="100%" cellpadding="1" cellspacing="0" border="0" id="con">
<tr>
<td width="90%"><b>Field 2:</b></td>
<td width="10%"><?php echo $data->field2; ?></td>
</tr>
<tr>
<td width="90%"><b>Field 3:</b></td>
<td width="10%"><?php echo $data->field3; ?></td>
</tr>
<tr>
<td width="90%"><b>Overall:</b></td>
<td width="10%"><?php
    $overall = $data->field1 + $data->field2 + $data->field3;
    echo round($overall / 3, 1);
?></td>
</tr>
</table>
<br>
<?php
}
?>

Also a way to inplement was Lightsaber mentioned would also be helpful as I would like it to display a result of 0 if no one has reviewed the anime.

leatherback

Tr this:


$query = @mysql_query("SELECT * FROM animereview WHERE animeid = '$id' ORDER BY id");
$i = 0;
$total = 0;

while ($data = @mysql_fetch_object($query)) {
?>
<table width="100%" cellpadding="1" cellspacing="0" border="0" id="con">
<tr>
<td width="90%"><b>Field 2:</b></td>
<td width="10%"><?php echo $data->field2; ?></td>
</tr>
<tr>
<td width="90%"><b>Field 3:</b></td>
<td width="10%"><?php echo $data->field3; ?></td>
</tr>
<tr>
<td width="90%"><b>Overall:</b></td>
<td width="10%"><?php
    $overall = $data->field1 + $data->field2 + $data->field3;
    $overall = round($overall / 3, 1);
    echo $overall;
    $total = $total + $overall;
    $i = $i + 1;

?></td>
</tr>
</table>
<br>
<?php
}
$overallscore = round($total / $i, 1);
echo $overallscore;
?>

xarnet

Ok that worked perfectly for what I needed although there is still a slight problem.. How do I get passed the fact that if there are 0 reviews and thus there would be 0 rows I get an error "Warning: Division by zero" which I assume is the $i = 0.

BeastRider

Originally posted by xarnet
Ok that worked perfectly for what I needed although there is still a slight problem.. How do I get passed the fact that if there are 0 reviews and thus there would be 0 rows I get an error "Warning: Division by zero" which I assume is the $i = 0.

Hmmm.... errr.... uhhhh.... well.... ahem.... ehhhhh.... toughie... not...

if ($i != 0)
{
// do your division thing
}
else
{
// plug a zero value
}

xarnet

Thanks to everyone that helped out, it's finally working...

/me realises he needs to study PHP a lot more..

I appreciate all the help and comments, I don't know what i would have done had you guys not been so helpful. So thanks again ^_