1.4 KiB
1.4 KiB
go-decimal-to-rational
Go library to convert decimal (float64) to rational fraction with required precision
Relies on Continued Fraction algorythm.
It's sometimes more appropriate than default big.Rat SetString, because
you can get 2/3 from 0.6666 by specifiing required precision. In big.Rat SetString
you can only get 3333/50000, and have no way to manipulate than (as of go 1.11).
Example
func ExampleNewRatP() {
fmt.Println(NewRatP(0.6666, 0.01).String())
fmt.Println(NewRatP(0.981, 0.001).String())
fmt.Println(NewRatP(0.75, 0.01).String())
// Output:
// 2/3
// 981/1000
// 3/4
}
func ExampleNewRatI() {
fmt.Println(NewRatI(0.6667, 3).String())
fmt.Println(NewRatI(0.6667, 4).String())
// Output:
// 2/3
// 6667/10000
}
Docs
import dectofrac "github.com/av-elier/go-decimal-to-rational"
func NewRatI
func NewRatI(val float64, iterations int64) *big.Rat
NewRatI returns rational from decimal using iterations number of
iterations in Continued Fraction algorythm
func NewRatP
func NewRatP(val float64, stepPrecision float64) *big.Rat
NewRatP returns rational from decimal by going as mush iterations, until
next fraction is less than stepPrecision