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1   /* ============================================================
2    * JRobin : Pure java implementation of RRDTool's functionality
3    * ============================================================
4    *
5    * Project Info:  http://www.jrobin.org
6    * Project Lead:  Sasa Markovic (saxon@jrobin.org);
7    *
8    * (C) Copyright 2003-2005, by Sasa Markovic.
9    *
10   * Developers:    Sasa Markovic (saxon@jrobin.org)
11   *
12   *
13   * This library is free software; you can redistribute it and/or modify it under the terms
14   * of the GNU Lesser General Public License as published by the Free Software Foundation;
15   * either version 2.1 of the License, or (at your option) any later version.
16   *
17   * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
18   * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
19   * See the GNU Lesser General Public License for more details.
20   *
21   * You should have received a copy of the GNU Lesser General Public License along with this
22   * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
23   * Boston, MA 02111-1307, USA.
24   */
25  
26  package org.jrobin.data;
27  
28  import org.jrobin.core.Util;
29  
30  import java.util.Arrays;
31  
32  class Normalizer {
33  	final private long[] timestamps;
34  	final int count;
35  	final long step;
36  
37  	Normalizer(long[] timestamps) {
38  		this.timestamps = timestamps;
39  		this.step = timestamps[1] - timestamps[0];
40  		this.count = timestamps.length;
41  	}
42  
43  	double[] normalize(long[] rawTimestamps, double[] rawValues) {
44  		int rawCount = rawTimestamps.length;
45  		long rawStep = rawTimestamps[1] - rawTimestamps[0];
46  		// check if we have a simple match
47  		if (rawCount == count && rawStep == step && rawTimestamps[0] == timestamps[0]) {
48  			return getCopyOf(rawValues);
49  		}
50  		// reset all normalized values to NaN
51  		double[] values = new double[count];
52  		Arrays.fill(values, Double.NaN);
53  		for (int rawSeg = 0, seg = 0; rawSeg < rawCount && seg < count; rawSeg++) {
54  			double rawValue = rawValues[rawSeg];
55  			if (!Double.isNaN(rawValue)) {
56  				long rawLeft = rawTimestamps[rawSeg] - rawStep;
57  				while (seg < count && rawLeft >= timestamps[seg]) {
58  					seg++;
59  				}
60  				boolean overlap = true;
61  				for (int fillSeg = seg; overlap && fillSeg < count; fillSeg++) {
62  					long left = timestamps[fillSeg] - step;
63  					long t1 = Math.max(rawLeft, left);
64  					long t2 = Math.min(rawTimestamps[rawSeg], timestamps[fillSeg]);
65  					if (t1 < t2) {
66  						values[fillSeg] = Util.sum(values[fillSeg], (t2 - t1) * rawValues[rawSeg]);
67  					}
68  					else {
69  						overlap = false;
70  					}
71  				}
72  			}
73  		}
74  		for (int seg = 0; seg < count; seg++) {
75  			values[seg] /= step;
76  		}
77  		return values;
78  	}
79  
80  	private static double[] getCopyOf(double[] rawValues) {
81  		int n = rawValues.length;
82  		double[] values = new double[n];
83  		System.arraycopy(rawValues, 0, values, 0, n);
84  		return values;
85  	}
86  }
87