package org.openjdk.jmh.util;
import org.apache.commons.math3.stat.descriptive.rank.Percentile;
import java.util.AbstractMap;
import java.util.Arrays;
import java.util.Iterator;
import java.util.Map;
public class ListStatistics extends AbstractStatistics {
private static final long serialVersionUID = -90642978235578197L;
private double[] values;
private int count;
public ListStatistics() {
values = new double[0];
count = 0;
}
public ListStatistics(double[] samples) {
this();
for (double d : samples) {
addValue(d);
}
}
public ListStatistics(long[] samples) {
this();
for (long l : samples) {
addValue((double) l);
}
}
public void addValue(double d) {
if (count >= values.length) {
values = Arrays.copyOf(values, Math.max(1, values.length << 1));
}
values[count] = d;
count++;
}
@Override
public double getMax() {
if (count > 0) {
double m = Double.NEGATIVE_INFINITY;
for (int i = 0; i < count; i++) {
m = Math.max(m, values[i]);
}
return m;
} else {
return Double.NaN;
}
}
@Override
public double getMin() {
if (count > 0) {
double m = Double.POSITIVE_INFINITY;
for (int i = 0; i < count; i++) {
m = Math.min(m, values[i]);
}
return m;
} else {
return Double.NaN;
}
}
@Override
public long getN() {
return count;
}
@Override
public double getSum() {
if (count > 0) {
double s = 0;
for (int i = 0; i < count; i++) {
s += values[i];
}
return s;
} else {
return Double.NaN;
}
}
@Override
public double getPercentile(double rank) {
if (count == 0) {
return Double.NaN;
}
if (rank == 0) {
return getMin();
}
values = Arrays.copyOf(values, count);
Percentile p = new Percentile();
return p.evaluate(values, rank);
}
@Override
public int[] getHistogram(double[] levels) {
if (levels.length < 2) {
throw new IllegalArgumentException("Expected more than two levels");
}
double[] vs = Arrays.copyOf(values, count);
Arrays.sort(vs);
int[] result = new int[levels.length - 1];
int c = 0;
values: for (double v : vs) {
while (levels[c] > v || v >= levels[c + 1]) {
c++;
if (c > levels.length - 2) break values;
}
result[c]++;
}
return result;
}
@Override
public Iterator<Map.Entry<Double, Long>> getRawData() {
return new ListStatisticsIterator();
}
@Override
public double getVariance() {
if (count > 1) {
double v = 0;
double m = getMean();
for (int i = 0; i < count; i++) {
v += Math.pow(values[i] - m, 2);
}
return v / (count - 1);
} else {
return Double.NaN;
}
}
private class ListStatisticsIterator implements Iterator<Map.Entry<Double, Long>> {
private int currentIndex = 0;
@Override
public boolean hasNext() {
return currentIndex < count;
}
@Override
public Map.Entry<Double, Long> next() {
return new AbstractMap.SimpleImmutableEntry<>(values[currentIndex++], 1L);
}
@Override
public void remove() {
throw new UnsupportedOperationException("Element cannot be removed.");
}
}
}