source: branches/ralph/src/main/java/de/ugoe/cs/autoquest/tasktrees/alignment/pal/tree/Tree.java @ 1612

// Tree.java
//
// (c) 1999-2001 PAL Development Core Team
//
// This package may be distributed under the
// terms of the Lesser GNU General Public License (LGPL)


package de.ugoe.cs.autoquest.tasktrees.alignment.pal.tree;



/**
 * Interface for a phylogenetic or genealogical tree.
 *
 * @version $Id: Tree.java,v 1.17 2001/11/20 03:44:49 alexi Exp $
 *
 * @author Alexei Drummond
 */
public interface Tree {

        /**
         * @return the root node of this tree.
         */
        Node getRoot();

        /**
         * This method constructs a tree from the given root node.
         * @param root the root node of the tree to construct.
         */
        void setRoot(Node root);

        /**
         * @return a count of the number of external nodes (tips) in this
         * tree.
         */
        int getExternalNodeCount();
        
        /**
         * @return a count of the number of internal nodes (and hence clades)
         * in this tree.
         */
        int getInternalNodeCount();

        /**
         * @return the ith external node in the tree.
         */
        Node getExternalNode(int i);
        
        /**
         * @return the ith internal node in the tree.
         */
        Node getInternalNode(int i);

        /**
         * This method is called to ensure that the calls to other methods
         * in this interface are valid.
         */
        void createNodeList();


}