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The math behind rating scripts

Hey,
Maths obviously isnt my strong point and i need some help in making a simple rating script, well i need to know the basics.

For example lets say i have an option of 1 - 5, a user can select a rating. Now this is where i get stuck.

The rating inputted into the database has to be between 1 & 5. lets say these are the values

PHP:

<?php

$current_rating = 3; // the rating from the database

$submitted_rating = 5; // submited by the user

$total_rates  = 23; // the total amount of votes taken from the db

//This is the thing i cant get my damn head around
$the_equasion = ?;

?>

So i hope i made it clear, anyone with any help would be apprechiated.

Thanks
Code

___________________

evolvedbb

Total rating number/number of times rated.

___________________

Fomerly known as lasnaranjas. Holler.

so that would be:

PHP:

<?php

$new_rating = $current_rating / $total_rates;

?>

but it gives the answer:
0.115625

where i want the answer to be between 1 and 5.

Correct me if im wrong (im real bad at things like this)

___________________

evolvedbb

Quote:

Originally posted by Code
so that would be:

PHP:

<?php

$new_rating = $current_rating / $total_rates;

?>

but it gives the answer:
0.115625

where i want the answer to be between 1 and 5.

Correct me if im wrong (im real bad at things like this)

say a user has n votes

vote_a = 3
vote_b = 5
vote_c =1;

in this case, n would be three

You'd want that to be

(vote_a + vote_b + vote_c)/ n

___________________

Fomerly known as lasnaranjas. Holler.

hmmm confusing :S

___________________

evolvedbb

its clicked in my head now, i understand how to do it

___________________

evolvedbb

this is kind of scary

___________________

Neverside Development Director
PHP Snippets
BigToach.com - IT WORKS, TOACHY!

Quote:

Originally posted by Code
so that would be:

PHP:

<?php

$new_rating = $current_rating / $total_rates;

?>

but it gives the answer:
0.115625

where i want the answer to be between 1 and 5.

Correct me if im wrong (im real bad at things like this)

wouldn;t it be...

[php]
$current_rating = ($current_rating + $new_rating) / $total_rates;
[php]

so it adds the new rating first then divids by the total...

[QUOTE]Originally posted by Natural
[B]wouldn;t it be...

[php]
$current_rating = ($current_rating + $new_rating) / $total_rates;
[php]

so it adds the new rating first then divids by the total... [/B][/QUOTE]

no you'd be averaging on an averge.

___________________

Fomerly known as lasnaranjas. Holler.

PHP:

<?php

$new_rating = (($current_rating * $total_rates) + $submitted_rating) / $total_rates + 1;
$new_total = $total_rates + 1;

?>

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