5 Star Rating formula

[slick101]

Hey does anyone know the formula for a 5 star rating system basically i have

.5 , 1 , 1.5 , 2 , 2.5 , 3 , 3.5 , 4, 4.5 , 5

Trying come up with a formula for the rating but i am having no luck.

[dagon]

explode in to an array
then use array_sum() and count()

[slick101]

dagon;10888510 wrote:

explode in to an array
then use array_sum() and count()

hey thanks for the reply the thing is though im storing the rating on the database.

so i have 2 fields called rating & vote_count.

the numbers I showed before i was justt writing what inputs could be sent in. 5 Stars rating.

so if someone voted now 5 i would guess the average, but maybe i was thinking this to much?

(input)5 / 1 (vote_count) = 5
then someone votes 3
(input)3 + (rating)5 / 2 = 4
then another vote 1.5
(input)1.5 + (rating)4 / 3 = 1.8
then another raitn 3.5
(input)3.5 + (Rating)1.8 / 4 = 1.3

so the average keeps going down. any idea?

[NogDog]

Assume the two fields in table "rating_table" are "rating" and "votes":

SELECT SUM( rating * votes ) / SUM( votes ) AS average_vote FROM rating_table

[slick101]

NogDog;10888514 wrote:

Assume the two fields in table "rating_table" are "rating" and "votes":

SELECT SUM( rating * votes ) / SUM( votes ) AS average_vote FROM rating_table

i was thinking to much, thanks got it working thank you 2.

[dagon]

woops :eek: