lancet/docs/mathutil.md

Mathutil

Package mathutil implements some functions for math calculation.

Source:

https://github.com/duke-git/lancet/blob/v1/mathutil/mathutil.go

Example:

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

Index

• Exponent
• Fibonacci
• Factorial
• Percent
• RoundToFloat
• RoundToString
• TruncRound
• AngleToRadian
• RadianToAngle
• PointDistance
• IsPrime

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
}

AngleToRadian

Converts angle value to radian value.

Signature:

func AngleToRadian(angle float64) float64

Example:

package main

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

func main() {
    result1 := mathutil.AngleToRadian(45)
    result2 := mathutil.AngleToRadian(90)
    result3 := mathutil.AngleToRadian(180)

    fmt.Println(result1)
    fmt.Println(result2)
    fmt.Println(result3)

    // Output:
    // 0.7853981633974483
    // 1.5707963267948966
    // 3.141592653589793
}

RadianToAngle

Converts radian value to angle value.

Signature:

func RadianToAngle(radian float64) float64

Example:

package main

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

func main() {
    result1 := mathutil.RadianToAngle(math.Pi)
    result2 := mathutil.RadianToAngle(math.Pi / 2)
    result3 := mathutil.RadianToAngle(math.Pi / 4)

    fmt.Println(result1)
    fmt.Println(result2)
    fmt.Println(result3)

    // Output:
    // 180
    // 90
    // 45
}

PointDistance

Caculates two points distance.

Signature:

func PointDistance(x1, y1, x2, y2 float64) float64

Example:

package main

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

func main() {
    result1 := mathutil.PointDistance(1, 1, 4, 5)

    fmt.Println(result1)

    // Output:
    // 5
}

IsPrime

Checks if number is prime number.

Signature:

func IsPrime(n int) bool

Example:

package main

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

func main() {
    result1 := mathutil.IsPrime(-1)
	result2 := mathutil.IsPrime(0)
	result3 := mathutil.IsPrime(1)
	result4 := mathutil.IsPrime(2)

	fmt.Println(result1)
	fmt.Println(result2)
	fmt.Println(result3)
	fmt.Println(result4)

	// Output:
	// false
	// false
	// false
	// true
}