Because CF need data to learn, small examples to illustrate adviserl are not easy to find. And thus the first “real” example is already a mis-use of adviserl: it uses the CF algorithm as an IR tool!

Anyway, here we go, I created a tag recommender with my delicious bookmarks (this is not new, delicious already display related tags, but this is just an application example toy).

This is done by considering each bookmark as a source (a user) and each tag as an item: each time a tag is associated with a bookmark, this is translated as “the bookmark rate the tag with a score of 1”. The complete code is this:
{ok, DeliciousPID} = deli_posts:start_link(),
gen_server:call(DeliciousPID, {login, User, Password}),
{ok, Posts, _Status} = gen_server:call(DeliciousPID, {get_posts, User, Options}, infinity),
io:format("Loading posts", []),
fun(#delipost{href=HRef,tags=Tags}) ->
io:format(".", []),
fun(Tag) -> adviserl:rate(HRef,Tag,{1,no_data}) end,
io:format("~n", []).
Getting a recommendation for few keywords is then:
Keywords = ["erlang", "concurrency"],
KeywordIDs = lists:map(fun(K) -> adv_items:id_from_key(K) end, Keywords),
Ratings = lists:map(fun(ID) -> {ID, 1} end, IDs),
Rec0 = adviserl:recommend_all(Ratings),
lists:map(fun({ID,_}) -> {ok,K} = adv_items:key_from_id(ID), K end, Rec0).

(lot of this code is about format and conversion, hopefully it will be done in next API release).

This delicious example toy can be run by in delicious example folder.

Yeah, I know, we can do the same more easily with few statistics (and R) and no CF … but (1) I needed a small example and (2) this could be extended to use different user accounts.

Hey! I should try to use citeUlike instead of delicious for the next example!