github.com/beorn7/perks v1.0.1: quantile.NewHighBiased

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify github.com/beorn7/perks/quantile.NewHighBiased in pkg:golang/github.com/beorn7/perks@v1.0.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/beorn7/perks@v1.0.1
Demonstrate these symbols/APIs:
  - github.com/beorn7/perks/quantile.NewHighBiased

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

package sample

import (
	"math"
	"testing"
)

func TestContractHighBiased(t *testing.T) {
	// 1. quantile.NewHighBiased initializes a quantile Stream with relative error guarantees for high rank quantiles
	epsilon := 0.01
	stream := NewHighBiasedStream(epsilon)
	if stream == nil {
		t.Fatal("expected non-nil stream from NewHighBiasedStream")
	}
	if count := stream.Count(); count != 0 {
		t.Fatalf("expected initial count 0, got %d", count)
	}

	// 2. quantile.Stream.Insert inserts float64 observations into the high-biased stream and increments Count
	n := 1000
	values := make([]float64, n)
	for i := 0; i < n; i++ {
		values[i] = float64(i + 1)
	}
	InsertValues(stream, values)

	if count := stream.Count(); count != n {
		t.Fatalf("expected count %d after insertions, got %d", n, count)
	}

	// 3. quantile.Stream.Query computes approximate high rank quantiles within relative error bounds
	p50 := QueryQuantile(stream, 0.50)
	expectedP50 := 500.0
	if math.Abs(p50-expectedP50) > 25.0 {
		t.Fatalf("expected p50 within [475, 525], got %f", p50)
	}

	p90 := QueryQuantile(stream, 0.90)
	expectedP90 := 900.0
	if math.Abs(p90-expectedP90) > 15.0 {
		t.Fatalf("expected p90 within [885, 915], got %f", p90)
	}

	p99 := QueryQuantile(stream, 0.99)
	expectedP99 := 990.0
	if math.Abs(p99-expectedP99) > 10.0 {
		t.Fatalf("expected p99 within [980, 1000], got %f", p99)
	}

	// 4. quantile.Stream.Reset clears high-biased stream observations and resets Count to 0
	ResetStream(stream)
	if count := stream.Count(); count != 0 {
		t.Fatalf("expected count 0 after reset, got %d", count)
	}
}

{"case":{"caseId":"case:sha256:61a35e824368c23ce0d6619d3e8eccfc4ea586f6659397e4a0fb6d94a9f40ab0","contract":["quantile.NewHighBiased initializes a quantile Stream with relative error guarantees for high rank quantiles","quantile.Stream.Insert inserts float64 observations into the high-biased stream and increments Count","quantile.Stream.Query computes approximate high rank quantiles within relative error bounds","quantile.Stream.Reset clears high-biased stream observations and resets Count to 0"],"goal":"verify github.com/beorn7/perks/quantile.NewHighBiased in pkg:golang/github.com/beorn7/perks@v1.0.1","kind":"HOW","packages":["pkg:golang/github.com/beorn7/perks@v1.0.1"],"schemaVersion":1,"symbols":["github.com/beorn7/perks/quantile.NewHighBiased"]},"contractCommand":["go","test","./..."],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/beorn7/perks@v1.0.1"],"schemaVersion":1,"subject":"pkg:golang/github.com/beorn7/perks@v1.0.1","symbols":["github.com/beorn7/perks/quantile.NewHighBiased"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.26.6

require github.com/beorn7/perks v1.0.1

github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=

package sample

import (
	"github.com/beorn7/perks/quantile"
)

// NewHighBiasedStream creates a new Stream targeting high-biased quantiles with relative error epsilon.
func NewHighBiasedStream(epsilon float64) *quantile.Stream {
	return quantile.NewHighBiased(epsilon)
}

// InsertValues inserts a slice of float64 data points into the quantile stream.
func InsertValues(stream *quantile.Stream, values []float64) {
	for _, v := range values {
		stream.Insert(v)
	}
}

// QueryQuantile queries the estimated value for a given quantile q (0.0 <= q <= 1.0).
func QueryQuantile(stream *quantile.Stream, q float64) float64 {
	return stream.Query(q)
}

// ResetStream clears all recorded data from the stream.
func ResetStream(stream *quantile.Stream) {
	stream.Reset()
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/beorn7/perks/quantile.NewHighBiased in pkg:golang/github.com/beorn7/perks@v1.0.1",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/beorn7/perks@v1.0.1"
  ],
  "symbols": [
    "github.com/beorn7/perks/quantile.NewHighBiased"
  ]
}