lancet/docs/mathutil.md

Mathutil

Package mathutil implements some functions for math calculation.

Source:

https://github.com/duke-git/lancet/blob/main/mathutil/mathutil.go

Example:

import (
    "github.com/duke-git/lancet/mathutil"
)

Index

• Exponent
• Fibonacci
• Factorial
• Percent
• RoundToFloat
• RoundToString
• TruncRound

Documentation

Exponent

Calculate x to the nth power.

Signature:

func Exponent(x, n int64) int64

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/mathutil"
)

func main() {
	fmt.Println(mathutil.Exponent(10, 0)) //1
	fmt.Println(mathutil.Exponent(10, 1)) //10
	fmt.Println(mathutil.Exponent(10, 2)) //100
}

Fibonacci

Calculate the nth number of fibonacci sequence.

Signature:

func Fibonacci(first, second, n int) int

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/mathutil"
)

func main() {
	fmt.Println(mathutil.Fibonacci(1, 1, 1)) //1
	fmt.Println(mathutil.Fibonacci(1, 1, 2)) //1
	fmt.Println(mathutil.Fibonacci(1, 1, 3)) //2
	fmt.Println(mathutil.Fibonacci(1, 1, 4)) //3
	fmt.Println(mathutil.Fibonacci(1, 1, 5)) //5
}

Factorial

Calculate the factorial of x.

Signature:

func Factorial(x uint) uint

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/mathutil"
)

func main() {
	fmt.Println(mathutil.Factorial(0)) //1
	fmt.Println(mathutil.Factorial(1)) //1
	fmt.Println(mathutil.Factorial(2)) //2
	fmt.Println(mathutil.Factorial(3)) //6
}

Percent

calculate the percentage of val to total, retain n decimal places.

Signature:

func Percent(val, total float64, n int) float64

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/mathutil"
)

func main() {
	fmt.Println(mathutil.Percent(1, 2, 2)) //1
	fmt.Println(mathutil.Percent(0.1, 0.3, 2)) //33.33
}

RoundToFloat

Round float up to n decimal places.

Signature:

func RoundToFloat(x float64, n int) float64

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/mathutil"
)

func main() {
	fmt.Println(mathutil.RoundToFloat(0, 0)) //0
	fmt.Println(mathutil.RoundToFloat(0, 1)) //0
	fmt.Println(mathutil.RoundToFloat(0.124, 2)) //0.12
	fmt.Println(mathutil.RoundToFloat(0.125, 2)) //0.13
	fmt.Println(mathutil.RoundToFloat(0.125, 3)) //0.125
}

RoundToString

Round float up to n decimal places. will return string.

Signature:

func RoundToString(x float64, n int) string

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/mathutil"
)

func main() {
	fmt.Println(mathutil.RoundToString(0, 0)) //"0"
	fmt.Println(mathutil.RoundToString(0, 1)) //"0.0:
	fmt.Println(mathutil.RoundToString(0.124, 2)) //"0.12"
	fmt.Println(mathutil.RoundToString(0.125, 2)) //"0.13"
	fmt.Println(mathutil.RoundToString(0.125, 3)) //"0.125"
}

TruncRound

Round float off n decimal places.

Signature:

func TruncRound(x float64, n int) float64

Example:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/mathutil"
)

func main() {
	fmt.Println(mathutil.TruncRound(0, 0)) //0
	fmt.Println(mathutil.TruncRound(0, 1)) //0
	fmt.Println(mathutil.TruncRound(0.124, 2)) //0.12
	fmt.Println(mathutil.TruncRound(0.125, 2)) //0.12
	fmt.Println(mathutil.TruncRound(0.125, 3)) //0.125
}