Basically I\'m just trying to switch my current sql statement which finds averages to do the same, but omit outliers. Here\'s my first one:
"SELECT a.*, AVG(b.rating) as rating FROM rand_thoughts a, ratings b WHERE b.rid=a.id GROUP BY b.rid ORDER BY rating DESC"
Works fine, but say you have the set of votes (from 1-10)
7
7
7
8
6
1
The outlier would obviously be one, and it would throw the voting. So I remembered finding the IQR in math class (I was so shocked that I was using something I actually learned, I\'ll have to tell my math teacher) to calculate the outliers after you\'ve found the 25th and 75th quartiles. But the problem is with the sql statement, this is what I\'ve come up with.
"SELECT a.id, b.rating FROM rand_thoughts a, ratings b WHERE b.rid=a.id && (b.rating > (AVG(b.rating)-STD(b.rating))) && (b.rating < (AVG(b.rating)+STD(b.rating) * .675)) GROUP BY b.rid"
I\'m pretty sure the logic works, but my problem is it gives me an error. This is the error from mysql_error():
Invalid use of group function
I\'ve searched google and all the programming forums that I know of, that\'s part of how I initially came up with finding the standard deviance to check for outliers.
Anyway, any help or suggestions would be great.
Thanks.