Struct oozie::recommender::KNNItemRecommender

pub struct KNNItemRecommender<'a, D: DataHandler + 'a> { /* fields omitted */ }

An item based nearest neighbors recommender

Methods

impl<'a, D: DataHandler + 'a> KNNItemRecommender<'a, D>

fn new(
    data_handler: &mut D,
    k: usize,
    similarity: fn(_: &HashMap<usize, f64>, _: &HashMap<usize, f64>, _: usize) -> f64
) -> KNNItemRecommender<D>

Initializes a new recommender from a data handler, computes and stores the similarities between items

fn add_user(&mut self, user_id: ID) -> bool

Adds an user to the data handler

fn add_item(&mut self, item_id: ID) -> bool

Adds an item to the data handler

fn add_rating(&mut self, user_id: ID, item_id: ID, rating: f64) -> bool

Adds a rating to the data handler, it computes the similarities for the item which had a new rating

Trait Implementations

impl<'a, D: DataHandler + 'a> Recommender for KNNItemRecommender<'a, D>

fn predict(&self, user_id: ID, item_id: ID) -> f64

Predicts a rating given an user and an item.

fn recommend(&self, user_id: ID) -> Vec<(ID, f64)>

Generates a sorted vector of item IDs by a predicted rating which is computed in the same way that the predict method. It ignores items that have a predicted rating of -1.0