question: public RFF_RBF ( int featurSize , double sigma , int dim , Random rand , boolean inMemory ) { this ( sigma , dim , inMemory ) ; if ( featurSize <= 0 ) throw new IllegalArgumentException ( "The number of numeric features must be positive, not " + featurSize ) ; if ( sigma <= 0 || Double . isInfinite ( sigma ) || Double . isNaN ( sigma ) ) throw new IllegalArgumentException ( "The sigma parameter must be positive, not " + sigma ) ; if ( dim <= 1 ) throw new IllegalArgumentException ( "The target dimension must be positive, not " + dim ) ; transform = new RandomMatrixRFF_RBF ( Math . sqrt ( 0.5 / ( sigma * sigma ) ) , featurSize , dim , rand . nextLong ( ) ) ; offsets = new RandomVectorRFF_RBF ( dim , rand . nextLong ( ) ) ; if ( inMemory ) { transform = transform . add ( 0.0 ) ; offsets = new DenseVector ( offsets ) ; } }
target:  Creates a new RFF RBF object