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Mathutil ​

Package mathutil implements some functions for math calculation.

Source: ​

Example: ​

go
import (
    "github.com/duke-git/lancet/v2/mathutil"
)

Index ​

Documentation ​

Average ​

Return average value of numbers. Maybe call RoundToFloat to round result.

Signature:

go
func Average[T constraints.Integer | constraints.Float](numbers ...T) float64

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Average(1, 2)

    avg := mathutil.Average(1.2, 1.4)
    result2 := mathutil.RoundToFloat(avg, 1)

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

    // Output:
    // 1.5
    // 1.3
}

Exponent ​

Calculate x to the nth power.

Signature:

go
func Exponent(x, n int64) int64

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Exponent(10, 0)
    result2 := mathutil.Exponent(10, 1)
    result3 := mathutil.Exponent(10, 2)

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

    // Output:
    // 1
    // 10
    // 100
}

Fibonacci ​

Calculate the nth number of fibonacci sequence.

Signature:

go
func Fibonacci(first, second, n int) int

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Fibonacci(1, 1, 1)
    result2 := mathutil.Fibonacci(1, 1, 2)
    result3 := mathutil.Fibonacci(1, 1, 5)

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

    // Output:
    // 1
    // 1
    // 5
}

Factorial ​

Calculate the factorial of x.

Signature:

go
func Factorial(x uint) uint

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Factorial(1)
    result2 := mathutil.Factorial(2)
    result3 := mathutil.Factorial(3)

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

    // Output:
    // 1
    // 2
    // 6
}

Max ​

Return max value of numbers.

Signature:

go
func Max[T constraints.Integer | constraints.Float](numbers ...T) T

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Max(1, 2, 3)
    result2 := mathutil.Max(1.2, 1.4, 1.1, 1.4)

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

    // Output:
    // 3
    // 1.4
}

MaxBy ​

Return the maximum value of a slice using the given comparator function.

Signature:

go
func MaxBy[T any](slice []T, comparator func(T, T) bool) T

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.MaxBy([]string{"a", "ab", "abc"}, func(v1, v2 string) bool {
        return len(v1) > len(v2)
    })

    result2 := mathutil.MaxBy([]string{"abd", "abc", "ab"}, func(v1, v2 string) bool {
        return len(v1) > len(v2)
    })

    result3 := mathutil.MaxBy([]string{}, func(v1, v2 string) bool {
        return len(v1) > len(v2)
    })

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

    // Output:
    // abc
    // abd
    //
}

Min ​

Return the minimum value of numbers.

Signature:

go
func Min[T constraints.Integer | constraints.Float](numbers ...T) T

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Min(1, 2, 3)
    result2 := mathutil.Min(1.2, 1.4, 1.1, 1.4)

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

    // Output:
    // 1
    // 1.1
}

MinBy ​

Return the minimum value of a slice using the given comparator function.

Signature:

go
func MinBy[T any](slice []T, comparator func(T, T) bool) T

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.MinBy([]string{"a", "ab", "abc"}, func(v1, v2 string) bool {
        return len(v1) < len(v2)
    })

    result2 := mathutil.MinBy([]string{"ab", "ac", "abc"}, func(v1, v2 string) bool {
        return len(v1) < len(v2)
    })

    result3 := mathutil.MinBy([]string{}, func(v1, v2 string) bool {
        return len(v1) < len(v2)
    })

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

    // Output:
    // a
    // ab
    //
}

Percent ​

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

Signature:

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

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Percent(1, 2, 2)
    result2 := mathutil.Percent(0.1, 0.3, 2)
    result3 := mathutil.Percent(-30305, 408420, 2)

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

    // Output:
    // 50
    // 33.33
    // -7.42
}

RoundToFloat ​

Round float up to n decimal places.

Signature:

go
func RoundToFloat[T constraints.Float | constraints.Integer](x T, n int) float64

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.RoundToFloat(0.124, 2)
    result2 := mathutil.RoundToFloat(0.125, 2)
    result3 := mathutil.RoundToFloat(0.125, 3)

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

    // Output:
    // 0.12
    // 0.13
    // 0.125
}

RoundToString ​

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

Signature:

go
func RoundToString[T constraints.Float | constraints.Integer](x T, n int) string

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.RoundToString(0.124, 2)
    result2 := mathutil.RoundToString(0.125, 2)
    result3 := mathutil.RoundToString(0.125, 3)

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

    // Output:
    // 0.12
    // 0.13
    // 0.125
}

TruncRound ​

Round float off n decimal places.

Signature:

go
func TruncRound[T constraints.Float | constraints.Integer](x T, n int) T

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.TruncRound(0.124, 2)
    result2 := mathutil.TruncRound(0.125, 2)
    result3 := mathutil.TruncRound(0.125, 3)

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

    // Output:
    // 0.12
    // 0.12
    // 0.125
}

CeilToFloat ​

Round float up n decimal places.

Signature:

go
func CeilToFloat[T constraints.Float | constraints.Integer](x T, n int) float64

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.CeilToFloat(3.14159, 1)
    result2 := mathutil.CeilToFloat(3.14159, 2)
    result3 := mathutil.CeilToFloat(5, 4)

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

    // Output:
    // 3.2
    // 3.15
    // 5
}

CeilToString ​

Round float up n decimal places.

Signature:

go
func CeilToString[T constraints.Float | constraints.Integer](x T, n int) string

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.CeilToString(3.14159, 1)
    result2 := mathutil.CeilToString(3.14159, 2)
    result3 := mathutil.CeilToString(5, 4)

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

    // Output:
    // 3.2
    // 3.15
    // 5.0000
}

FloorToFloat ​

Round float down n decimal places.

Signature:

go
func FloorToFloat[T constraints.Float | constraints.Integer](x T, n int) float64

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.FloorToFloat(3.14159, 1)
    result2 := mathutil.FloorToFloat(3.14159, 2)
    result3 := mathutil.FloorToFloat(5, 4)

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

    // Output:
    // 3.1
    // 3.14
    // 5
}

FloorToString ​

Round float down n decimal places.

Signature:

go
func FloorToString[T constraints.Float | constraints.Integer](x T, n int) string

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.FloorToString(3.14159, 1)
    result2 := mathutil.FloorToString(3.14159, 2)
    result3 := mathutil.FloorToString(5, 4)

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

    // Output:
    // 3.1
    // 3.14
    // 5.0000
}

Range ​

Creates a slice of numbers from start with specified count, element step is 1.

Signature:

go
func Range[T constraints.Integer | constraints.Float](start T, count int) []T

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Range(1, 4)
    result2 := mathutil.Range(1, -4)
    result3 := mathutil.Range(-4, 4)
    result4 := mathutil.Range(1.0, 4)

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

    // Output:
    // [1 2 3 4]
    // [1 2 3 4]
    // [-4 -3 -2 -1]
    // [1 2 3 4]
}

RangeWithStep ​

Creates a slice of numbers from start to end with specified step.

Signature:

go
func RangeWithStep[T constraints.Integer | constraints.Float](start, end, step T) []T

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.RangeWithStep(1, 4, 1)
    result2 := mathutil.RangeWithStep(1, -1, 0)
    result3 := mathutil.RangeWithStep(-4, 1, 2)
    result4 := mathutil.RangeWithStep(1.0, 4.0, 1.1)

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

    // Output:
    // [1 2 3]
    // []
    // [-4 -2 0]
    // [1 2.1 3.2]
}

AngleToRadian ​

Converts angle value to radian value.

Signature:

go
func AngleToRadian(angle float64) float64

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/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:

go
func RadianToAngle(radian float64) float64

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/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:

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

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

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

    fmt.Println(result1)

    // Output:
    // 5
}

IsPrime ​

Checks if number is prime number.

Signature:

go
func IsPrime(n int) bool

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/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
}

GCD ​

Return greatest common divisor (GCD) of integers.

Signature:

go
func GCD[T constraints.Integer](integers ...T) T

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.GCD(1, 1)
    result2 := mathutil.GCD(1, -1)
    result3 := mathutil.GCD(-1, 1)
    result4 := mathutil.GCD(-1, -1)
    result5 := mathutil.GCD(3, 6, 9)

    fmt.Println(result1)
    fmt.Println(result2)
    fmt.Println(result3)
    fmt.Println(result4)
    fmt.Println(result5)

    // Output:
    // 1
    // 1
    // -1
    // -1
    // 3
}

LCM ​

Return Least Common Multiple (LCM) of integers.

Signature:

go
func LCM[T constraints.Integer](integers ...T) T

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.LCM(1, 1)
    result2 := mathutil.LCM(1, 2)
    result3 := mathutil.LCM(3, 6, 9)

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

    // Output:
    // 1
    // 2
    // 18
}

Cos ​

Returns the cosine of the radian argument.

Signature:

go
func Cos(radian float64, precision ...int) float64

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Cos(0)
    result2 := mathutil.Cos(90)
    result3 := mathutil.Cos(180)
    result4 := mathutil.Cos(math.Pi)
    result5 := mathutil.Cos(math.Pi / 2)

    fmt.Println(result1)
    fmt.Println(result2)
    fmt.Println(result3)
    fmt.Println(result4)
    fmt.Println(result5)

    // Output:
    // 1
    // -0.447
    // -0.598
    // -1
    // 0
}

Sin ​

Returns the sine of the radian argument.

Signature:

go
func Sin(radian float64, precision ...int) float64

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Sin(0)
    result2 := mathutil.Sin(90)
    result3 := mathutil.Sin(180)
    result4 := mathutil.Sin(math.Pi)
    result5 := mathutil.Sin(math.Pi / 2)

    fmt.Println(result1)
    fmt.Println(result2)
    fmt.Println(result3)
    fmt.Println(result4)
    fmt.Println(result5)

    // Output:
    // 0
    // 0.894
    // -0.801
    // 0
    // 1
}

Log ​

Returns the logarithm of base n.

Signature:

go
func Log(n, base float64) float64

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Log(8, 2)
    result2 := mathutil.TruncRound(mathutil.Log(5, 2), 2)
    result3 := mathutil.TruncRound(mathutil.Log(27, 3), 0)

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

    // Output:
    // 3
    // 2.32
    // 3
}

Sum ​

Returns sum of passed numbers.

Signature:

go
func Sum[T constraints.Integer | constraints.Float](numbers ...T) T

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Sum(1, 2)
    result2 := mathutil.Sum(0.1, float64(1))

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

    // Output:
    // 3
    // 1.1
}

Abs ​

Returns the absolute value of x.

Signature:

go
func Abs[T constraints.Integer | constraints.Float](x T) T

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Abs(-1)
    result2 := mathutil.Abs(-0.1)
    result3 := mathutil.Abs(float32(0.2))

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

    // Output:
    // 1
    // 0.1
    // 0.2
}

Div ​

Returns the result of x divided by y.

Signature:

go
func Div[T constraints.Float | constraints.Integer](x T, y T) float64

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Div(9, 4)
    result2 := mathutil.Div(1, 2)
    result3 := mathutil.Div(0, 666)

    fmt.Println(result1)
    fmt.Println(result2)
    fmt.Println(result3)
    // Output:
    // 2.25
    // 0.5
    // 0
}

Variance ​

Returns the variance of numbers.

Signature:

go
func Variance[T constraints.Float | constraints.Integer](numbers []T) float64

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Variance([]int{1, 2, 3, 4, 5})
    result2 := mathutil.Variance([]float64{1.1, 2.2, 3.3, 4.4, 5.5})

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

    // Output:
    // 2
    // 2.42
}

StdDev ​

Returns the standard deviation of numbers.

Signature:

go
func StdDev[T constraints.Float | constraints.Integer](numbers []T) float64

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.TruncRound(mathutil.StdDev([]int{1, 2, 3, 4, 5}), 2)
    result2 := mathutil.TruncRound(mathutil.StdDev([]float64{1.1, 2.2, 3.3, 4.4, 5.5}), 2)

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

    // Output:
    // 1.41
    // 1.55
}

Permutation ​

Calculates P(n, k).

Signature:

go
func Permutation(n, k uint) uint

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Permutation(5, 3)
	result2 := mathutil.Permutation(5, 5)

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

	// Output:
	// 60
	// 120
}

Combination ​

Calculates C(n, k).

Signature:

go
func Combination(n, k uint) uint

Example:Run

go
package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.Combination(5, 3)
	result2 := mathutil.Combination(5, 5)

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

	// Output:
	// 10
	// 1
}