package org.rrd4j.graph;
import org.rrd4j.core.Util;
import java.util.Arrays;
class Normalizer {
private final double[] timestamps;
final int count;
final double step;
Normalizer(long tStart, long tEnd, int count) {
this.count = count;
this.step = (tEnd - tStart) / (count - 1);
this.timestamps = new double[count];
for (int i = 0; i < count; i++) {
this.timestamps[i] = tStart + ((double) i / (double) (count - 1)) * (tEnd - tStart);
}
}
double[] getTimestamps() {
return timestamps;
}
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++) {
double left = timestamps[fillSeg] - step;
double t1 = Math.max(rawLeft, left);
double 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;
}
}