recpack.algorithms.KUNN
- class recpack.algorithms.KUNN(Ku: int = 100, Ki: int = 100)
Unified Nearest Neighbour algorithm combining user and item neighbourhood methods.
KUNN Algorithm as described in ‘Unifying Nearest Neighbors Collaborative Filtering’ Verstrepen et al. (10.1145/2645710.2645731)
Computes the item KNN model and stores training interactions at fitting time. Computes the user KNN model between test and training users at prediction time.
Scores are computed as a sum of item and user similarity.
user KNN are computed using
\[sim(u,v) = \sum_{i \in I} { \frac{ R_{ui} R_{vi}}{\sqrt{c(u) c(v) c(i)}}}\]item KNN are computed as
\[sim(i,j) = \sum_{u \in U} { \frac{ R_{ui} R_{vi}}{\sqrt{c(i) c(u) c(j)}}}\]Similarity is computed as
\[sim(u, i) = S_U(u, i) + S_I(u, i)\]Where user similarity is computed as
\[S_U(u, i) = \sum_{v \in KNN(u)} \frac{R_{vi} * sim(u,v)}{\sqrt{c(i)}}\]and item similarity is computed as
\[S_I(u, i) = \sum_{j \in KNN(i)} \frac{R_{uj} * sim(i, j)}{\sqrt{c(u)}}\]- Parameters
Ku (int, optional) – How many neighbours to keep in the user similarity matrix. Defaults to 100.
Ki (int, optional) – How many items to keep as neighbours in the item similarity matrix. Defaults to 100.
Methods
fit
(X)Fit the model to the input interaction matrix.
Get metadata routing of this object.
get_params
([deep])Get parameters for this estimator.
predict
(X)Predicts scores, given the interactions in X
set_params
(**params)Set the parameters of the estimator.
Attributes
Name of the object.
Name of the object's class.
- fit(X: Union[recpack.matrix.interaction_matrix.InteractionMatrix, scipy.sparse._csr.csr_matrix]) recpack.algorithms.base.Algorithm
Fit the model to the input interaction matrix.
After fitting the model will be ready to use for prediction.
This function will handle some generic bookkeeping for each of the child classes,
The fit function gets timed, and this will get printed
Input data is converted to expected type using call to
_transform_predict_input()
The model is trained using the
_fit()
method_check_fit_complete()
is called to check fitting was succesful
- Parameters
X (Matrix) – The interactions to fit the model on.
- Returns
self, fitted algorithm
- Return type
- get_metadata_routing()
Get metadata routing of this object.
Please check User Guide on how the routing mechanism works.
- Returns
routing – A
MetadataRequest
encapsulating routing information.- Return type
MetadataRequest
- get_params(deep=True)
Get parameters for this estimator.
- Parameters
deep (bool, default=True) – If True, will return the parameters for this estimator and contained subobjects that are estimators.
- Returns
params – Parameter names mapped to their values.
- Return type
dict
- property identifier
Name of the object.
Name is made by combining the class name with the parameters passed at construction time.
Constructed by recreating the initialisation call. Example:
Algorithm(param_1=value)
- property name
Name of the object’s class.
- predict(X: Union[recpack.matrix.interaction_matrix.InteractionMatrix, scipy.sparse._csr.csr_matrix]) scipy.sparse._csr.csr_matrix
Predicts scores, given the interactions in X
Recommends items for each nonzero user in the X matrix.
This function is a wrapper around the
_predict()
method, and performs checks on in- and output data to guarantee proper computation.Checks that model is fitted correctly
checks the output using
_check_prediction()
function
- Parameters
X (Matrix) – interactions to predict from.
- Returns
The recommendation scores in a sparse matrix format.
- Return type
csr_matrix
- set_params(**params)
Set the parameters of the estimator.
- Parameters
params (dict) – Estimator parameters