// We don't compute fractional MutableDistribution, it's either whole or none.
internal override void Combine(MutableAggregation other, double fraction)
{
MutableDistribution mutableDistribution = other as MutableDistribution;
if (mutableDistribution == null)
{
throw new ArgumentException("MutableDistribution expected.");
}
if (Math.Abs(1.0 - fraction) > TOLERANCE)
{
return;
}
if (!(this.BucketBoundaries.Equals(mutableDistribution.BucketBoundaries)))
{
throw new ArgumentException("Bucket boundaries should match.");
}
// Algorithm for calculating the combination of sum of squared deviations:
// https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance#Parallel_algorithm.
if (this.Count + mutableDistribution.Count > 0)
{
double delta = mutableDistribution.Mean - this.Mean;
this.SumOfSquaredDeviations =
this.SumOfSquaredDeviations
+ mutableDistribution.SumOfSquaredDeviations
+ Math.Pow(delta, 2)
* this.Count
* mutableDistribution.Count
/ (this.Count + mutableDistribution.Count);
}
this.Count += mutableDistribution.Count;
this.Sum += mutableDistribution.Sum;
this.Mean = this.Sum / this.Count;
if (mutableDistribution.Min < this.Min)
{
this.Min = mutableDistribution.Min;
}
if (mutableDistribution.Max > this.Max)
{
this.Max = mutableDistribution.Max;
}
long[] bucketCounts = mutableDistribution.BucketCounts;
for (int i = 0; i < bucketCounts.Length; i++)
{
this.BucketCounts[i] += bucketCounts[i];
}
}
private static void Sum(MutableAggregation combined, IAggregationData data)
{
data.Match <object>(
(arg) =>
{
MutableSum sum = combined as MutableSum;
if (sum != null)
{
sum.Add(arg.Sum);
}
return(null);
},
(arg) =>
{
MutableSum sum = combined as MutableSum;
if (sum != null)
{
sum.Add(arg.Sum);
}
return(null);
},
(arg) =>
{
MutableCount count = combined as MutableCount;
if (count != null)
{
count.Add(arg.Count);
}
return(null);
},
(arg) =>
{
MutableMean mean = combined as MutableMean;
if (mean != null)
{
mean.Count = mean.Count + arg.Count;
mean.Sum = mean.Sum + (arg.Count * arg.Mean);
if (arg.Min < mean.Min)
{
mean.Min = arg.Min;
}
if (arg.Max > mean.Max)
{
mean.Max = arg.Max;
}
}
return(null);
},
(arg) =>
{
MutableDistribution dist = combined as MutableDistribution;
if (dist != null)
{
// Algorithm for calculating the combination of sum of squared deviations:
// https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance#Parallel_algorithm.
if (dist.Count + arg.Count > 0)
{
double delta = arg.Mean - dist.Mean;
dist.SumOfSquaredDeviations =
dist.SumOfSquaredDeviations
+ arg.SumOfSquaredDeviations
+ Math.Pow(delta, 2)
* dist.Count
* arg.Count
/ (dist.Count + arg.Count);
}
dist.Count += arg.Count;
dist.Sum += (arg.Mean * arg.Count);
dist.Mean = dist.Sum / dist.Count;
if (arg.Min < dist.Min)
{
dist.Min = arg.Min;
}
if (arg.Max > dist.Max)
{
dist.Max = arg.Max;
}
IList <long> bucketCounts = arg.BucketCounts;
for (int i = 0; i < bucketCounts.Count; i++)
{
dist.BucketCounts[i] += bucketCounts[i];
}
}
return(null);
},
(arg) =>
{
MutableLastValue lastValue = combined as MutableLastValue;
if (lastValue != null)
{
lastValue.initialized = true;
if (Double.IsNaN(lastValue.LastValue))
{
lastValue.LastValue = arg.LastValue;
}
else
{
lastValue.LastValue += arg.LastValue;
}
}
return(null);
},
(arg) =>
{
MutableLastValue lastValue = combined as MutableLastValue;
if (lastValue != null)
{
lastValue.initialized = true;
if (Double.IsNaN(lastValue.LastValue))
{
lastValue.LastValue = arg.LastValue;
}
else
{
lastValue.LastValue += arg.LastValue;
}
}
return(null);
},
(arg) =>
{
throw new ArgumentException();
});
}
