summary

README

Summary

summary is a lightweight Go library for computing summary statistics from numeric collections and streams.

It provides an API inspired by Java's IntSummaryStatistics and DoubleSummaryStatistics, while following idiomatic Go design.

Features

• Generic support for integer and floating-point slices
• Read numbers directly from any io.Reader
• Configurable tokenization using bufio.SplitFunc
• bufio.ScanWords is used by default when no split function is provided
• Computes:
  • Count
  • Sum
  • Average
  • Minimum
  • Maximum
• Invalid tokens are ignored when reading streams
• Dependency-free

Installation

go get github.com/marcelo-sjr/summary_statistics

Usage

Slice

stats := summary.Ints(10, 20, 30, 40)

fmt.Println(stats.Count)
fmt.Println(stats.Sum)
fmt.Println(stats.Avg)
fmt.Println(stats.Min)
fmt.Println(stats.Max)

Floating-point slice

stats := summary.Floats(1.5, 2.5, 3.5)

fmt.Println(stats.Count)
fmt.Println(stats.Sum)
fmt.Println(stats.Avg)
fmt.Println(stats.Min)
fmt.Println(stats.Max)

Reading from streams

ReadInts and ReadFloats accept any io.Reader.

By default, input is tokenized using bufio.ScanWords. You may provide a custom bufio.SplitFunc when different tokenization is required.

Default behavior

file, err := os.Open("numbers.txt")
if err != nil {
	log.Fatal(err)
}
defer file.Close()

stats, err := summary.ReadInts(file, nil)
if err != nil {
	log.Fatal(err)
}

Input:

10 20 30 40

---

One value per line

stats, err := summary.ReadInts(file, bufio.ScanLines)

Input:

10
20
30
40

---

Space-separated values

stats, err := summary.ReadInts(file, bufio.ScanWords)

Input:

10 20 30 40

---

Mixed input

Invalid tokens are ignored.

10
20
hello
30
40 foo
50

Only numeric tokens are included in the statistics.

API

Slice functions

summary.Ints[T integer](values ...T) IntSummary
summary.Floats[T float](values ...T) FloatSummary

Reader functions

summary.ReadInts(r io.Reader, split bufio.SplitFunc) (IntSummary, error)
summary.ReadFloats(r io.Reader, split bufio.SplitFunc) (FloatSummary, error)

License

MIT License.

Documentation

Index

• type FloatSummary
  • func Floats[T float](t ...T) FloatSummary
  • func ReadFloats(r io.Reader, split bufio.SplitFunc) (FloatSummary, error)
• type IntSummary
  • func Ints[T integer](t ...T) IntSummary
  • func ReadInts(r io.Reader, split bufio.SplitFunc) (IntSummary, error)

Types

type FloatSummary

type FloatSummary struct {
	Count int
	Sum   float64
	Avg   float64
	Min   float64
	Max   float64
}

func Floats

func Floats[T float](t ...T) FloatSummary

Floats computes summary statistics for a collection of floating-point values. If the input is float32, the returned statistics are promoted to float64.

func ReadFloats

func ReadFloats(r io.Reader, split bufio.SplitFunc) (FloatSummary, error)

ReadFloats reads floating-point numbers from r and computes summary statistics.

Input can be tokenized using the provided bufio.SplitFunc. If split is nil, bufio.ScanWords is used. Each token is parsed using strconv.ParseFloat with the bitSize=64. Tokens that cannot be parsed are ignored.

ReadFloats does not close r; the caller is responsible for closing it, if necessary.

If the scanner encounters an I/O error, an empty FloatSummary and the corresponding error are returned.

type IntSummary

type IntSummary struct {
	Count int
	Sum   int64
	Avg   float64
	Min   int64
	Max   int64
}

func Ints

func Ints[T integer](t ...T) IntSummary

Ints computes summary statistics for a collection of integer values. The average is returned as a float64.

func ReadInts

func ReadInts(r io.Reader, split bufio.SplitFunc) (IntSummary, error)

ReadInts reads integers from r and computes summary statistics.

Input can be tokenized using the provided bufio.SplitFunc. If split is nil, bufio.ScanWords is used. Each token is parsed as an integer using strconv.Atoi. Tokens that cannot be parsed are ignored.

ReadInts does not close r; the caller is responsible for closing it, if necessary.

If the scanner encounters an I/O error, an empty IntSummary and the corresponding error are returned.