use kahan for avg_over_time

Signed-off-by: darshanime <deathbullet@gmail.com>
This commit is contained in:
darshanime 2021-10-25 18:02:25 +05:30
parent 0a9deb9597
commit a905354da3

View File

@ -367,7 +367,7 @@ func aggrOverTime(vals []parser.Value, enh *EvalNodeHelper, aggrFn func([]Point)
// === avg_over_time(Matrix parser.ValueTypeMatrix) Vector ===
func funcAvgOverTime(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) Vector {
return aggrOverTime(vals, enh, func(values []Point) float64 {
var mean, count float64
var mean, count, c float64
for _, v := range values {
count++
if math.IsInf(mean, 0) {
@ -387,9 +387,13 @@ func funcAvgOverTime(vals []parser.Value, args parser.Expressions, enh *EvalNode
continue
}
}
mean += v.V/count - mean/count
mean, c = kahanSummationIter(v.V/count-mean/count, mean, c)
}
return mean
if math.IsInf(mean, 0) {
return mean
}
return mean + c
})
}