pkg/stats: split out pkg/stats/sample

This will reduce the number of dependencies needed for the main
syzkaller tools.

1 files changed, 0 insertions, 73 deletions

diff --git a/pkg/stats/sample.go b/pkg/stats/sample.go
deleted file mode 100644
index 668675fc1..000000000
--- a/pkg/stats/sample.go
+++ /dev/null
@@ -1,73 +0,0 @@
-// Copyright 2021 syzkaller project authors. All rights reserved.
-// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
-
-// Package stats provides various statistical operations and algorithms.
-package stats
-
-import (
-	"math"
-	"sort"
-)
-
-// Sample represents a single sample - set of data points collected during an experiment.
-type Sample struct {
-	Xs     []float64
-	Sorted bool
-}
-
-func (s *Sample) Percentile(p float64) float64 {
-	s.Sort()
-	// The code below is taken from golang.org/x/perf/internal/stats
-	// Unfortunately, that package is internal and we cannot just import and use it.
-	N := float64(len(s.Xs))
-	n := 1/3.0 + p*(N+1/3.0) // R8
-	kf, frac := math.Modf(n)
-	k := int(kf)
-	if k <= 0 {
-		return s.Xs[0]
-	} else if k >= len(s.Xs) {
-		return s.Xs[len(s.Xs)-1]
-	}
-	return s.Xs[k-1] + frac*(s.Xs[k]-s.Xs[k-1])
-}
-
-func (s *Sample) Median() float64 {
-	return s.Percentile(0.5)
-}
-
-// Remove outliers by the Tukey's fences method.
-func (s *Sample) RemoveOutliers() *Sample {
-	if len(s.Xs) < 4 {
-		// If the data set is too small, we cannot reliably detect outliers anyway.
-		return s.Copy()
-	}
-	s.Sort()
-	Q1 := s.Percentile(0.25)
-	Q3 := s.Percentile(0.75)
-	minValue := Q1 - 1.5*(Q3-Q1)
-	maxValue := Q3 + 1.5*(Q3-Q1)
-	xs := []float64{}
-	for _, value := range s.Xs {
-		if value >= minValue && value <= maxValue {
-			xs = append(xs, value)
-		}
-	}
-	return &Sample{
-		Xs:     xs,
-		Sorted: s.Sorted,
-	}
-}
-
-func (s *Sample) Copy() *Sample {
-	return &Sample{
-		Xs:     append([]float64{}, s.Xs...),
-		Sorted: s.Sorted,
-	}
-}
-
-func (s *Sample) Sort() {
-	if !s.Sorted {
-		sort.Slice(s.Xs, func(i, j int) bool { return s.Xs[i] < s.Xs[j] })
-		s.Sorted = true
-	}
-}