comb

README

comb

This library provides the ability to split Slice elements into multiple groups.
The approach is to solve combinatorial optimization problems by minimizing the energy function.

Usage

The interface is similar to sort.Slice. It can be used as the following example.

target := []float64{1.0, 2.0, 3.0, 3.5, 4.0, 3.8}
score := func(ind []int) float64 {
	total := 0.0
	for _, i := range ind {
		total += target[i]
	}
	return total
}
energy := func(inds [][]int) float64 {
	var min, max float64
	for _, ind := range inds {
		s := score(ind)
		if min > s {
			min = s
		}
		if max < s {
			max = s
		}
	}
	return (max - min) * (max - min)
}
groups := comb.Slice(target, 4, energy)

for _, group := range groups {
	fmt.Printf("[")
	for _, i := range group {
		fmt.Printf(" %f ", target[i])
	}
	fmt.Printf("] => %f\n", score(group))
}
//Output:
//[ 1.000000  3.800000 ] => 4.800000
//[ 2.000000  3.000000 ] => 5.000000
//[ 3.500000 ] => 3.500000
//[ 4.000000 ] => 4.000000

Documentation

Index

• func Slice(slice interface{}, groupCount int, energy func(i [][]int) float64, ...) [][]int
• type Config
• type Option
  • func MaxIter(n int) Option
  • func Seed(n int64) Option

Examples

• Slice

Functions

func Slice

func Slice(slice interface{}, groupCount int, energy func(i [][]int) float64, options ...Option) [][]int

Example

package main

import (
	"fmt"

	"github.com/mashiike/comb"
)

func main() {
	target := []float64{1.0, 2.0, 3.0, 3.5, 4.0, 3.8}
	score := func(ind []int) float64 {
		total := 0.0
		for _, i := range ind {
			total += target[i]
		}
		return total
	}
	energy := func(inds [][]int) float64 {
		var min, max float64
		for _, ind := range inds {
			s := score(ind)
			if min > s {
				min = s
			}
			if max < s {
				max = s
			}
		}
		return (max - min) * (max - min)
	}
	groups := comb.Slice(target, 4, energy, comb.Seed(1))

	for _, group := range groups {
		fmt.Printf("[")
		for _, i := range group {
			fmt.Printf(" %f ", target[i])
		}
		fmt.Printf("] => %f\n", score(group))
	}
}

Output:

[ 1.000000  3.800000 ] => 4.800000
[ 2.000000  3.000000 ] => 5.000000
[ 3.500000 ] => 3.500000
[ 4.000000 ] => 4.000000

Types

type Config

type Config struct {
	// contains filtered or unexported fields
}

type Option

type Option func(*Config)

func MaxIter

func MaxIter(n int) Option

func Seed

func Seed(n int64) Option