For now in Joomla Book Library
if admin set Book rating in admin arrea. Book Library - will show that reating.
If admin set rating == 0, rating will cpollect from all reviews for this book.
If you need some other algorithm
We may propose to you order this as "customization service".
Please write to OrdaSoft contact form (ordasoft.com/contact-us-form
) with full details description, how all must look and work, and we will give to you quota.