calculating the percentile in java code example
Example 1: calculating the percentile in java
public static long[] percentiles(long[] latencies, double... percentiles) {
Arrays.sort(latencies, 0, latencies.length);
long[] values = new long[percentiles.length];
for (int i = 0; i < percentiles.length; i++) {
int index = (int) (percentiles[i] * latencies.length);
values[i] = latencies[index];
}
return values;
}
Example 2: calculating the percentile in java
for (i=0, sum=0; i<n; i++) sum += Number[i];
tot = sum;
for (i=0, sum=0; i<n && sum < 0.95*tot; i++) sum += Number[i];
// i is about it
Example 3: calculating the percentile in java
/**
* A simple method to log 95th percentile information
*/
private static void logPercentileInfo() {
double total = 0;
for (Map.Entry<Long, Long> entry : CassandraTimer.histogram.entrySet()) {
long value = entry.getKey() * entry.getValue();
total += value;
}
double sum = 0.95*total;
double totalSum = 0;
SortedSet<Long> keys = new TreeSet<Long>(CassandraTimer.histogram.keySet());
for (long key : keys) {
totalSum += CassandraTimer.histogram.get(key);
if(totalSum >= sum) {
//this is the 95th percentile I guess
System.out.println(key);
}
}
}