GClasses
GClasses::GBagOfRecommenders Class Reference

Detailed Description

This class performs bootstrap aggregation with collaborative filtering algorithms.

#include <GRecommender.h>

Inheritance diagram for GClasses::GBagOfRecommenders:
GClasses::GCollaborativeFilter

Public Member Functions

 GBagOfRecommenders ()
 General-purpose constructor. More...
 
 GBagOfRecommenders (const GDomNode *pNode, GLearnerLoader &ll)
 Deserialization constructor. More...
 
virtual ~GBagOfRecommenders ()
 Destructor. More...
 
void addRecommender (GCollaborativeFilter *pRecommender)
 Add a filter to the bag. More...
 
void clear ()
 Delete all of the filters. More...
 
std::vector< GCollaborativeFilter * > & filters ()
 Returns the vector of filters. More...
 
virtual void impute (GVec &vec, size_t dims)
 See the comment for GCollaborativeFilter::impute. More...
 
virtual double predict (size_t user, size_t item)
 See the comment for GCollaborativeFilter::predict. More...
 
virtual GDomNodeserialize (GDom *pDoc) const
 See the comment for GCollaborativeFilter::serialize. More...
 
virtual void train (GMatrix &data)
 See the comment for GCollaborativeFilter::train. More...
 
- Public Member Functions inherited from GClasses::GCollaborativeFilter
 GCollaborativeFilter ()
 
 GCollaborativeFilter (const GDomNode *pNode, GLearnerLoader &ll)
 
virtual ~GCollaborativeFilter ()
 
void basicTest (double minMSE)
 Performs a basic unit test on this collaborative filter. More...
 
double crossValidate (GMatrix &data, size_t folds, double *pOutMAE=NULL)
 This randomly assigns each rating to one of the folds. Then, for each fold, it calls train with a dataset that contains everything except for the ratings in that fold. It predicts values for the items in the fold, and returns the mean-squared difference between the predictions and the actual ratings. If pOutMAE is non-NULL, it will be set to the mean-absolute error. More...
 
GMatrixprecisionRecall (GMatrix &data, bool ideal=false)
 This divides the data into two equal-size parts. It trains on one part, and then measures the precision/recall using the other part. It returns a three-column data set with recall scores in column 0 and corresponding precision scores in column 1. The false-positive rate is in column 2. (So, if you want a precision-recall plot, just drop column 2. If you want an ROC curve, drop column 1 and swap the remaining two columns.) This method assumes the ratings range from 0 to 1, so be sure to scale the ratings to fit that range before calling this method. If ideal is true, then it will ignore your model and report the ideal results as if your model always predicted the correct rating. (This is useful because it shows the best possible results.) More...
 
GRandrand ()
 Returns a reference to the pseudo-random number generator associated with this object. More...
 
double trainAndTest (GMatrix &train, GMatrix &test, double *pOutMAE=NULL)
 This trains on the training set, and then tests on the test set. Returns the mean-squared difference between actual and target predictions. More...
 
void trainDenseMatrix (const GMatrix &data, const GMatrix *pLabels=NULL)
 Train from an m-by-n dense matrix, where m is the number of users and n is the number of items. All attributes must be continuous. Missing values are indicated with UNKNOWN_REAL_VALUE. If pLabels is non-NULL, then the labels will be appended as additional items. More...
 

Static Public Member Functions

static void test ()
 Performs unit tests. Throws if a failure occurs. Returns if successful. More...
 
- Static Public Member Functions inherited from GClasses::GCollaborativeFilter
static double areaUnderCurve (GMatrix &data)
 Pass in the data returned by the precisionRecall function (unmodified), and this will compute the area under the ROC curve. More...
 

Protected Attributes

std::vector< GCollaborativeFilter * > m_filters
 
size_t m_itemCount
 
- Protected Attributes inherited from GClasses::GCollaborativeFilter
GRand m_rand
 

Additional Inherited Members

- Protected Member Functions inherited from GClasses::GCollaborativeFilter
GDomNodebaseDomNode (GDom *pDoc, const char *szClassName) const
 Child classes should use this in their implementation of serialize. More...
 

Constructor & Destructor Documentation

GClasses::GBagOfRecommenders::GBagOfRecommenders ( )

General-purpose constructor.

GClasses::GBagOfRecommenders::GBagOfRecommenders ( const GDomNode pNode,
GLearnerLoader ll 
)

Deserialization constructor.

virtual GClasses::GBagOfRecommenders::~GBagOfRecommenders ( )
virtual

Destructor.

Member Function Documentation

void GClasses::GBagOfRecommenders::addRecommender ( GCollaborativeFilter pRecommender)

Add a filter to the bag.

void GClasses::GBagOfRecommenders::clear ( )

Delete all of the filters.

std::vector<GCollaborativeFilter*>& GClasses::GBagOfRecommenders::filters ( )
inline

Returns the vector of filters.

virtual void GClasses::GBagOfRecommenders::impute ( GVec vec,
size_t  dims 
)
virtual
virtual double GClasses::GBagOfRecommenders::predict ( size_t  user,
size_t  item 
)
virtual
virtual GDomNode* GClasses::GBagOfRecommenders::serialize ( GDom pDoc) const
virtual
static void GClasses::GBagOfRecommenders::test ( )
static

Performs unit tests. Throws if a failure occurs. Returns if successful.

virtual void GClasses::GBagOfRecommenders::train ( GMatrix data)
virtual

Member Data Documentation

std::vector<GCollaborativeFilter*> GClasses::GBagOfRecommenders::m_filters
protected
size_t GClasses::GBagOfRecommenders::m_itemCount
protected