RatioMapping.java

package edu.brown.mappings;


public class RatioMapping extends AbstractMapping {
    private int num_equal = 0;
    

    /**
     * Constructor
     */
    public RatioMapping() {
        // Nothing for now...
    }

    /**
     * Remove all entries in this RatioCorrelation instance
     */
    public void clear() {
        super.clear();
        this.num_equal = 0;
    }
    
    /**
     * Add two values to be correlated with each other
     * 
     * @param x
     * @param y
     */
    public synchronized <K extends Number, V extends Number> void addOccurrence(K x, V y) {
        if (x == null) return;
        if (x.equals(y)) {
            this.num_equal++;
        }
//        else {
//            System.err.printf("%s[%s] != %s[%s]\n",
//                              x, x.getClass().getSimpleName(),
//                              y, y.getClass().getSimpleName());
//        }
        this.num_entries++;
        this.last_calculation = null;
    }

    /**
     * 
     */
    public synchronized Double calculate() {
        if (this.last_calculation != null || this.num_entries == 0) return (this.last_calculation);
        this.last_calculation = this.num_equal / (double)this.num_entries;
        return (this.last_calculation);
    }
}