pkg/stat: rename package name to singular form

Go package names should generally be singular form:

https://go.dev/blog/package-names
https://rakyll.org/style-packages
https://groups.google.com/g/golang-nuts/c/buBwLar1gNw

3 files changed, 0 insertions, 159 deletions

diff --git a/pkg/stats/sample/pvalue.go b/pkg/stats/sample/pvalue.go
deleted file mode 100644
index acfff4bc4..000000000
--- a/pkg/stats/sample/pvalue.go
+++ /dev/null
@@ -1,20 +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 sample
-
-// TODO: I didn't find the substitution as of Feb 2023. Let's keep it as is while it works.
-import "golang.org/x/perf/benchstat" // nolint:all
-
-// Mann-Whitney U test.
-func UTest(old, new *Sample) (pval float64, err error) {
-	// Unfortunately we cannot just invoke MannWhitneyUTest from x/perf/benchstat/internal/stats,
-	// so we first wrap the data in Metrics.
-	mOld := benchstat.Metrics{
-		RValues: old.Xs,
-	}
-	mNew := benchstat.Metrics{
-		RValues: new.Xs,
-	}
-	return benchstat.UTest(&mOld, &mNew)
-}
diff --git a/pkg/stats/sample/sample.go b/pkg/stats/sample/sample.go
deleted file mode 100644
index 740f9aefe..000000000
--- a/pkg/stats/sample/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 sample provides various statistical operations and algorithms.
-package sample
-
-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
-	}
-}
diff --git a/pkg/stats/sample/sample_test.go b/pkg/stats/sample/sample_test.go
deleted file mode 100644
index ac7845ccf..000000000
--- a/pkg/stats/sample/sample_test.go
+++ /dev/null
@@ -1,66 +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 sample
-
-import (
-	"reflect"
-	"testing"
-)
-
-func TestMedian(t *testing.T) {
-	tests := []struct {
-		input     []float64
-		minMedian float64
-		maxMedian float64
-	}{
-		{
-			input:     []float64{1, 2, 3},
-			minMedian: 1.99, // we cannot do exact floating point equality comparison
-			maxMedian: 2.01,
-		},
-		{
-			input:     []float64{0, 1, 2, 3},
-			minMedian: 1.0,
-			maxMedian: 2.0,
-		},
-	}
-	for _, test := range tests {
-		sample := Sample{Xs: test.input}
-		median := sample.Median()
-		if median < test.minMedian || median > test.maxMedian {
-			t.Errorf("sample %v, median got %v, median expected [%v;%v]",
-				test.input, median, test.minMedian, test.maxMedian)
-		}
-	}
-}
-
-func TestRemoveOutliers(t *testing.T) {
-	// Some tests just to check the overall sanity of the method.
-	tests := []struct {
-		input  []float64
-		output []float64
-	}{
-		{
-			input:  []float64{-20, 1, 2, 3, 4, 5},
-			output: []float64{1, 2, 3, 4, 5},
-		},
-		{
-			input:  []float64{1, 2, 3, 4, 25},
-			output: []float64{1, 2, 3, 4},
-		},
-		{
-			input:  []float64{-10, -5, 0, 5, 10, 15},
-			output: []float64{-10, -5, 0, 5, 10, 15},
-		},
-	}
-	for _, test := range tests {
-		sample := Sample{Xs: test.input}
-		result := sample.RemoveOutliers()
-		result.Sort()
-		if !reflect.DeepEqual(result.Xs, test.output) {
-			t.Errorf("input: %v, expected no outliers: %v, got: %v",
-				test.input, test.output, result.Xs)
-		}
-	}
-}