/*******************************************************************************
* 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.ConsolFuns;
import org.jrobin.core.Util;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
class Aggregator implements ConsolFuns {
private long timestamps[], step;
private double[] values;
Aggregator(long[] timestamps, double[] values) {
assert timestamps.length == values.length: "Incompatible timestamps/values arrays (unequal lengths)";
assert timestamps.length >= 2: "At least two timestamps must be supplied";
this.timestamps = timestamps;
this.values = values;
this.step = timestamps[1] - timestamps[0];
}
Aggregates getAggregates(long tStart, long tEnd) {
Aggregates agg = new Aggregates();
int cnt = 0;
int lslstep = 0;
boolean firstFound = false;
double SUMx, SUMy, SUMxy, SUMxx, SUMyy;
SUMx = 0.0;
SUMy = 0.0;
SUMxy = 0.0;
SUMxx = 0.0;
SUMyy = 0.0;
for (int i = 0; i < timestamps.length; i++) {
long left = Math.max(timestamps[i] - step, tStart);
long right = Math.min(timestamps[i], tEnd);
long delta = right - left;
// delta is only >= 0 when the timestamp for a given buck is within the range of tStart and tEnd
if (delta >= 0) {
double value = values[i];
agg.min = Util.min(agg.min, value);
agg.max = Util.max(agg.max, value);
if (!firstFound) {
agg.first = value;
firstFound = true;
agg.last = value;
} else if (delta >= step) { // an entire bucket is included in this range
agg.last = value;
/*
* Algorithmically, we're only updating last if it's either the first
* bucket encountered, or it's a "full" bucket.
if ( !isInRange(tEnd, left, right) ||
(isInRange(tEnd, left, right) && !Double.isNaN(value))
) {
agg.last = value;
}
*/
}
if (!Double.isNaN(value)) {
cnt++;
SUMx += lslstep;
SUMxx += lslstep * lslstep;
SUMy = Util.sum(SUMy, value);
SUMxy = Util.sum(SUMxy, lslstep * value);
SUMyy = Util.sum(SUMyy, value * value);
}
lslstep ++;
}
}
agg.average = cnt > 0 ? (SUMy / cnt) : Double.NaN;
// Work on STDEV
if (cnt > 0) {
double stdevSum = 0.0;
for (int i = 0; i < timestamps.length; i++) {
long left = Math.max(timestamps[i] - step, tStart);
long right = Math.min(timestamps[i], tEnd);
long delta = right - left;
// delta is only >= 0 when the timestamp for a given buck is within the range of tStart and tEnd
if (delta >= 0) {
double value = values[i];
if (!Double.isNaN(value)) {
stdevSum = Util.sum(stdevSum, Math.pow((value - agg.average), 2.0));
}
}
}
agg.stdev = Math.pow(stdevSum / cnt, 0.5);
/* Bestfit line by linear least squares method */
agg.lslslope = (SUMx * SUMy - cnt * SUMxy) / (SUMx * SUMx - cnt * SUMxx);
agg.lslint = (SUMy - agg.lslslope * SUMx) / cnt;
agg.lslcorrel =
(SUMxy - (SUMx * SUMy) / cnt) /
Math.sqrt((SUMxx - (SUMx * SUMx) / cnt) * (SUMyy - (SUMy * SUMy) / cnt));
}
agg.total = SUMy * step;
return agg;
}
double getPercentile(long tStart, long tEnd, double percentile) {
return getPercentile(tStart, tEnd, percentile, false);
}
double getPercentile(long tStart, long tEnd, double percentile, boolean includenan) {
List<Double> valueList = new ArrayList<Double>();
// create a list of included datasource values (different from NaN)
for (int i = 0; i < timestamps.length; i++) {
long left = Math.max(timestamps[i] - step, tStart);
long right = Math.min(timestamps[i], tEnd);
if (right > left && (!Double.isNaN(values[i]) || includenan)) {
valueList.add(values[i]);
}
}
// create an array to work with
int count = valueList.size();
if (count > 1) {
double[] valuesCopy = new double[count];
for (int i = 0; i < count; i++) {
valuesCopy[i] = valueList.get(i);
}
// sort array
Arrays.sort(valuesCopy);
// skip top (100% - percentile) values
double topPercentile = (100.0 - percentile) / 100.0;
count -= (int) Math.ceil(count * topPercentile);
// if we have anything left...
if (count > 0) {
return valuesCopy[count - 1];
}
}
// not enough data available
return Double.NaN;
}
}