/*******************************************************************************
* Copyright (c) 2001-2005 Sasa Markovic and Ciaran Treanor.
* Copyright (c) 2011 The OpenNMS Group, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*******************************************************************************/
package org.jrobin.data;
import org.jrobin.core.Util;
import java.util.Arrays;
class Normalizer {
final private long[] timestamps;
final int count;
final long step;
Normalizer(long[] timestamps) {
this.timestamps = timestamps;
this.step = timestamps[1] - timestamps[0];
this.count = timestamps.length;
}
double[] normalize(long[] rawTimestamps, double[] rawValues) {
int rawCount = rawTimestamps.length;
long rawStep = rawTimestamps[1] - rawTimestamps[0];
// check if we have a simple match
if (rawCount == count && rawStep == step && rawTimestamps[0] == timestamps[0]) {
return getCopyOf(rawValues);
}
// reset all normalized values to NaN
double[] values = new double[count];
Arrays.fill(values, Double.NaN);
for (int rawSeg = 0, seg = 0; rawSeg < rawCount && seg < count; rawSeg++) {
double rawValue = rawValues[rawSeg];
if (!Double.isNaN(rawValue)) {
long rawLeft = rawTimestamps[rawSeg] - rawStep;
while (seg < count && rawLeft >= timestamps[seg]) {
seg++;
}
boolean overlap = true;
for (int fillSeg = seg; overlap && fillSeg < count; fillSeg++) {
long left = timestamps[fillSeg] - step;
long t1 = Math.max(rawLeft, left);
long t2 = Math.min(rawTimestamps[rawSeg], timestamps[fillSeg]);
if (t1 < t2) {
values[fillSeg] = Util.sum(values[fillSeg], (t2 - t1) * rawValues[rawSeg]);
}
else {
overlap = false;
}
}
}
}
for (int seg = 0; seg < count; seg++) {
values[seg] /= step;
}
return values;
}
private static double[] getCopyOf(double[] rawValues) {
int n = rawValues.length;
double[] values = new double[n];
System.arraycopy(rawValues, 0, values, 0, n);
return values;
}
}