search for: latitude_string

Hi all, I''m trying to figure out how to add a filter into a search. I''ve created the filter, basically copying the location filter from http://blog.tourb.us/archives/ferret-and-location-based-searches. But when I try to call Index.search and pass the filter in a hash with the key :filter, I get back that it is expecting type Data, and so I''m at a loss to figure out