001// --- BEGIN LICENSE BLOCK ---
002/* 
003 * Copyright (c) 2009, Mikio L. Braun
004 * All rights reserved.
005 * 
006 * Redistribution and use in source and binary forms, with or without
007 * modification, are permitted provided that the following conditions are
008 * met:
009 * 
010 *     * Redistributions of source code must retain the above copyright
011 *       notice, this list of conditions and the following disclaimer.
012 * 
013 *     * Redistributions in binary form must reproduce the above
014 *       copyright notice, this list of conditions and the following
015 *       disclaimer in the documentation and/or other materials provided
016 *       with the distribution.
017 * 
018 *     * Neither the name of the Technische Universität Berlin nor the
019 *       names of its contributors may be used to endorse or promote
020 *       products derived from this software without specific prior
021 *       written permission.
022 * 
023 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
024 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
025 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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035// --- END LICENSE BLOCK ---
036
037/*
038 * To change this template, choose Tools | Templates
039 * and open the template in the editor.
040 */
041
042package org.jblas.ranges;
043
044import org.jblas.*;
045
046/**
047 * Range which varies over pre-specified indices.
048 * 
049 * For example,
050 * <pre>
051 *     int[] indices = new int[] { 1, 1, 2, 3, 5, 8, 13 };
052 *     Range r = new IndicesRange(indices);</pre>
053 * ranges over the first few Fibonacci numbers.
054 */
055public class IndicesRange implements Range {
056    private int[] indices;
057    private int counter;
058        
059    /** Initialize from integer array. */
060    public IndicesRange(int[] is) {
061        indices = is;
062    }
063    
064    public void init(int l, int u) {
065        counter = 0;
066    }
067    
068    /** 
069     * Initialize from DoubleMatrix. Entries are converted to integers
070     * by truncation.
071     */
072    public IndicesRange(DoubleMatrix is) {
073        this(is.toIntArray());
074    }
075    
076    public int length() {
077        return indices.length;
078    }
079    
080    public void next() {
081        counter++;
082    }
083    
084    public int index() {
085        return counter;
086    }
087
088    public int value() {
089        return indices[counter];
090    }
091    
092    public boolean hasMore() {
093        return counter < indices.length;
094    }
095}