I'm creating a digg-like site using Ruby on Rails that ranks the item (based on this algorithm). I'm using the will-paginate gem list the items in pages. The problem is, will-paginate only allows me to insert ':order =' based on the table data. I would like to make will-paginate to sort by a number which is calculated using a function based on different fields on the table (e.g number of votes, age hours). How can I do that?