goext/mathext/statistics.go

97 lines
1.9 KiB
Go
Raw Normal View History

2022-10-27 16:00:57 +02:00
package mathext
2024-07-12 16:33:42 +02:00
import (
"gogs.mikescher.com/BlackForestBytes/goext/exerr"
"gogs.mikescher.com/BlackForestBytes/goext/langext"
)
2022-10-27 17:03:30 +02:00
func Sum[T langext.NumberConstraint](v []T) T {
total := T(0)
2022-10-27 16:00:57 +02:00
for _, v := range v {
total += v
}
return total
}
2022-10-27 17:03:30 +02:00
func Mean[T langext.FloatConstraint](v []T) T {
return Sum(v) / T(len(v))
2022-10-27 16:00:57 +02:00
}
2022-10-27 17:03:30 +02:00
func Median[T langext.FloatConstraint](v []T) T {
2022-10-27 16:00:57 +02:00
if len(v)%2 == 1 {
return v[len(v)/2]
} else {
2022-10-27 17:03:30 +02:00
return (v[len(v)/2-1] + v[len(v)/2]) / T(2)
2022-10-27 16:00:57 +02:00
}
}
2022-10-27 17:03:30 +02:00
func ArrMin[T langext.OrderedConstraint](v []T) T {
2022-10-27 16:00:57 +02:00
r := v[0]
for _, val := range v {
if val < r {
r = val
}
}
return r
}
2022-10-27 17:03:30 +02:00
func ArrMax[T langext.OrderedConstraint](v []T) T {
2022-10-27 16:00:57 +02:00
r := v[0]
for _, val := range v {
if val > r {
r = val
}
}
return r
}
2024-07-12 16:33:42 +02:00
func MustPercentile[T langext.NumberConstraint](rawdata []T, percentile float64) T {
v, err := Percentile(rawdata, percentile)
if err != nil {
panic(err)
}
return v
}
func Percentile[T langext.NumberConstraint](rawdata []T, percentile float64) (T, error) {
v, err := FloatPercentile(rawdata, percentile)
if err != nil {
return T(0), err
}
return T(v), nil
}
func FloatPercentile[T langext.NumberConstraint](rawdata []T, percentile float64) (float64, error) {
if len(rawdata) == 0 {
return 0, exerr.New(exerr.TypeAssert, "no data to calculate percentile").Any("percentile", percentile).Build()
}
if percentile < 0 || percentile > 100 {
return 0, exerr.New(exerr.TypeAssert, "percentile out of range").Any("percentile", percentile).Build()
}
data := langext.ArrCopy(rawdata)
langext.Sort(data)
idxFloat := float64(len(data)-1) * (percentile / float64(100))
idxInt := int(idxFloat)
// exact match on index
if idxFloat == float64(idxInt) {
return float64(data[idxInt]), nil
}
// linear interpolation
v1 := data[idxInt]
v2 := data[idxInt+1]
weight := idxFloat - float64(idxInt)
valFloat := (float64(v1) * (1 - weight)) + (float64(v2) * weight)
return valFloat, nil
}