LeafNode.java

package edu.northwestern.cbits.purple_robot_manager.models.trees;

import java.util.HashMap;
import java.util.Map;

/**
 * Encapsulates a leaf node that returns a prediction.
 */

public class LeafNode extends TreeNode
{
    public static final String PREDICTION = "prediction";
    public static final String ACCURACY = "accuracy";

    private HashMap<String, Object> _prediction;

    /**
     * Construct a new leaf node and assign its prediction.
     * 
     * @param prediction
     *            Prediction containing at least a LeafNode.PREDICTION key-value
     *            pair as well as a LeafNode.ACCURACY estimate of the accuracy
     *            or confidence of this prediction. Parsers may add additional
     *            keys as needed.
     */

    public LeafNode(String name, HashMap<String, Object> prediction)
    {
        super(name);

        this._prediction = prediction;

        this._prediction.put(TreeNode.NAME, name);
    }

    public LeafNode(HashMap<String, Object> prediction)
    {
        super(null);

        this._prediction = prediction;
    }

    /**
     * Returns the prediction associated with this leaf node.
     * 
     * @see edu.northwestern.cbits.purple_robot_manager.models.trees.TreeNode#fetchPrediction(java.util.Map)
     */

    public Map<String, Object> fetchPrediction(Map<String, Object> features)
    {
        return this._prediction;
    }

    /**
     * Returns a representation of the leaf node in "PREDICTION (ACCURACY)"
     * format for human consumption.
     * 
     * @see edu.northwestern.cbits.purple_robot_manager.models.trees.TreeNode#toString(int)
     */

    public String toString(int indent)
    {
        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < indent; i++)
            sb.append("  ");

        sb.append(this._prediction.get(LeafNode.PREDICTION).toString());
        sb.append(" (");
        sb.append(_prediction.get(LeafNode.ACCURACY).toString());
        sb.append(")");

        return sb.toString();
    }
}