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docs/api/packages/maputil.md Normal file
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# Mathutil
mathutil 包实现了一些数学计算的函数.
<div STYLE="page-break-after: always;"></div>
## 源码:
- [https://github.com/duke-git/lancet/blob/main/mathutil/mathutil.go](https://github.com/duke-git/lancet/blob/main/mathutil/mathutil.go)
<div STYLE="page-break-after: always;"></div>
## 用法:
```go
import (
"github.com/duke-git/lancet/v2/mathutil"
)
```
<div STYLE="page-break-after: always;"></div>
## 目录
- [Average](#Average)
- [Exponent](#Exponent)
- [Fibonacci](#Fibonacci)
- [Factorial](#Factorial)
- [Max](#Max)
- [MaxBy](#MaxBy)
- [Min](#Min)
- [MinBy](#MaxBy)
- [Percent](#Percent)
- [RoundToFloat](#RoundToFloat)
- [RoundToString](#RoundToString)
- [TruncRound](#TruncRound)
- [Range](#Range)
- [RangeWithStep](#RangeWithStep)
- [AngleToRadian](#AngleToRadian)
- [RadianToAngle](#RadianToAngle)
- [PointDistance](#PointDistance)
- [IsPrime](#IsPrime)
- [GCD](#GCD)
- [LCM](#LCM)
- [Cos](#Cos)
- [Sin](#Sin)
- [Log](#Log)
- [Sum](#Sum)
- [Abs](#Abs)
<div STYLE="page-break-after: always;"></div>
<link rel="stylesheet" type="text/css" href="../../styles/api_doc.css">
## 文档
### <span id="Average">Average</span>
<p>计算平均数. 可能需要对结果调用RoundToFloat方法四舍五入</p>
<b>函数签名:</b>
```go
func Average[T constraints.Integer | constraints.Float](numbers ...T) T
```
<b>示例:</b>
```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
// 1.3
}
```
### <span id="Exponent">Exponent</span>
<p>指数计算（x的n次方）</p>
<b>函数签名:</b>
```go
func Exponent(x, n int64) int64
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/Vv7LBwER-pz)</span></b>
```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
}
```
### <span id="Fibonacci">Fibonacci</span>
<p>计算斐波那契数列的第n个数</p>
<b>函数签名:</b>
```go
func Fibonacci(first, second, n int) int
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/IscseUNMuUc)</span></b>
```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
}
```
### <span id="Factorial">Factorial</span>
<p>计算阶乘</p>
<b>函数签名:</b>
```go
func Factorial(x uint) uint
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/tt6LdOK67Nx)</span></b>
```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
}
```
### <span id="Max">Max</span>
<p>返回参数中的最大数</p>
<b>函数签名:</b>
```go
func Max[T constraints.Integer | constraints.Float](numbers ...T) T
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/cN8DHI0rTkH)</span></b>
```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
}
```
### <span id="MaxBy">MaxBy</span>
<p>使用给定的比较器函数返回切片的最大值</p>
<b>函数签名:</b>
```go
func MaxBy[T any](slice []T, comparator func(T, T) bool) T
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/pbe2MT-7DV2)</span></b>
```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
//
}
```
### <span id="Min">Min</span>
<p>返回参数中的最小数</p>
<b>函数签名:</b>
```go
func Min[T constraints.Integer | constraints.Float](numbers ...T) T
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/pbe2MT-7DV2)</span></b>
```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
}
```
### <span id="MinBy">MinBy</span>
<p>使用给定的比较器函数返回切片的最小值</p>
<b>函数签名:</b>
```go
func MinBy[T any](slice []T, comparator func(T, T) bool) T
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/N9qgYg_Ho6f)</span></b>
```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
//
}
```
### <span id="Percent">Percent</span>
<p>计算百分比，保留n位小数</p>
<b>函数签名:</b>
```go
func Percent(val, total float64, n int) float64
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/s0NdFCtwuyd)</span></b>
```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
}
```
### <span id="RoundToFloat">RoundToFloat</span>
<p>四舍五入，保留n位小数</p>
<b>函数签名:</b>
```go
func RoundToFloat(x float64, n int) float64
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/ghyb528JRJL)</span></b>
```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
}
```
### <span id="RoundToString">RoundToString</span>
<p>四舍五入，保留n位小数，返回字符串</p>
<b>函数签名:</b>
```go
func RoundToString(x float64, n int) string
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/kZwpBRAcllO)</span></b>
```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
}
```
### <span id="TruncRound">TruncRound</span>
<p>截短n位小数（不进行四舍五入）</p>
<b>函数签名:</b>
```go
func TruncRound(x float64, n int) float64
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/aumarSHIGzP)</span></b>
```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
}
```
### <span id="Range">Range</span>
<p>根据指定的起始值和数量，创建一个数字切片。</p>
<b>函数签名:</b>
```go
func Range[T constraints.Integer | constraints.Float](start T, count int) []T
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/9ke2opxa8ZP)</span></b>
```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]
}
```
### <span id="RangeWithStep">RangeWithStep</span>
<p>根据指定的起始值，结束值，步长，创建一个数字切片。</p>
<b>函数签名:</b>
```go
func RangeWithStep[T constraints.Integer | constraints.Float](start, end, step T) []T
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/akLWz0EqOSM)</span></b>
```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]
}
```
### <span id="AngleToRadian">AngleToRadian</span>
<p>将角度值转为弧度值</p>
<b>函数签名:</b>
```go
func AngleToRadian(angle float64) float64
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/CIvlICqrHql)</span></b>
```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
}
```
### <span id="RadianToAngle">RadianToAngle</span>
<p>将弧度值转为角度值</p>
<b>函数签名:</b>
```go
func RadianToAngle(radian float64) float64
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/dQtmOTUOMgi)</span></b>
```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
}
```
### <span id="PointDistance">PointDistance</span>
<p>计算两个坐标点的距离</p>
<b>函数签名:</b>
```go
func PointDistance(x1, y1, x2, y2 float64) float64
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/RrG4JIaziM8)</span></b>
```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
}
```
### <span id="IsPrime">IsPrime</span>
<p>判断质数。</p>
<b>函数签名:</b>
```go
func IsPrime(n int) bool
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/Rdd8UTHZJ7u)</span></b>
```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
}
```
### <span id="GCD">GCD</span>
<p>计算最大公约数。</p>
<b>函数签名:</b>
```go
func GCD[T constraints.Integer](integers ...T) T
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/CiEceLSoAKB)</span></b>
```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
}
```
### <span id="LCM">LCM</span>
<p>计算最小公倍数。</p>
<b>函数签名:</b>
```go
func LCM[T constraints.Integer](integers ...T) T
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/EjcZxfY7G_g)</span></b>
```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
}
```
### <span id="Cos">Cos</span>
<p>计算弧度的余弦值</p>
<b>函数签名:</b>
```go
func Cos(radian float64, precision ...int) float64
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/Sm89LoIfvFq)</span></b>
```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
}
```
### <span id="Sin">Sin</span>
<p>计算弧度的正弦值</p>
<b>函数签名:</b>
```go
func Sin(radian float64, precision ...int) float64
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/TWMQlMywDsP)</span></b>
```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
}
```
### <span id="Log">Log</span>
<p>计算以base为底n的对数。</p>
<b>函数签名:</b>
```go
func Log(n, base float64) float64
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/_d4bi8oyhat)</span></b>
```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
}
```
### <span id="Sum">Sum</span>
<p>求传入参数之和。</p>
<b>函数签名:</b>
```go
func Sum[T constraints.Integer | constraints.Float](numbers ...T) T
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/1To2ImAMJA7)</span></b>
```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
}
```
### <span id="Abs">Abs</span>
<p>求绝对值。</p>
<b>函数签名:</b>
```go
func Abs[T constraints.Integer | constraints.Float](x T) T
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/fsyBh1Os-1d)</span></b>
```go
package main
import (
"fmt"
"github.com/duke-git/lancet/v2/mathutil"
)
func main() {
result1 := Abs(-1)
result2 := Abs(-0.1)
result3 := Abs(float32(0.2))
fmt.Println(result1)
fmt.Println(result2)
fmt.Println(result3)
// Output:
// 1
// 0.1
// 0.2
}
```

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# Pointer
pointer 包支持一些指针类型的操作。
<div STYLE="page-break-after: always;"></div>
## 源码:
- [https://github.com/duke-git/lancet/blob/main/pointer/pointer.go](https://github.com/duke-git/lancet/blob/main/pointer/pointer.go)
<div STYLE="page-break-after: always;"></div>
## 用法:
```go
import (
"github.com/duke-git/lancet/v2/pointer"
)
```
<div STYLE="page-break-after: always;"></div>
## 目录
- [Of](#Of)
- [Unwrap](#Unwrap)
- [ExtractPointer](#ExtractPointer)
- [UnwarpOr](#UnwarpOr)
- [UnwarpOrDefault](#UnwarpOrDefault)
<div STYLE="page-break-after: always;"></div>
<link rel="stylesheet" type="text/css" href="../../styles/api_doc.css">
## 文档
### <span id="Of">Of</span>
<p>返回传入参数的指针值。</p>
<b>函数签名:</b>
```go
func Of[T any](v T) *T
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/HFd70x4DrMj)</span></b>
```go
package main
import (
"fmt"
"github.com/duke-git/lancet/v2/pointer"
)
func main() {
result1 := pointer.Of(123)
result2 := pointer.Of("abc")
fmt.Println(*result1)
fmt.Println(*result2)
// Output:
// 123
// abc
}
```
### <span id="Unwrap">Unwrap</span>
<p>返回传入指针指向的值。</p>
<b>函数签名:</b>
```go
func Unwrap[T any](p *T) T
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/cgeu3g7cjWb)</span></b>
```go
package main
import (
"fmt"
"github.com/duke-git/lancet/v2/pointer"
)
func main() {
a := 123
b := "abc"
result1 := pointer.Unwrap(&a)
result2 := pointer.Unwrap(&b)
fmt.Println(result1)
fmt.Println(result2)
// Output:
// 123
// abc
}
```
### <span id="ExtractPointer">ExtractPointer</span>
<p>返回传入interface的底层值。</p>
<b>函数签名:</b>
```go
func ExtractPointer(value any) any
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/D7HFjeWU2ZP)</span></b>
```go
package main
import (
"fmt"
"github.com/duke-git/lancet/v2/pointer"
)
func main() {
a := 1
b := &a
c := &b
d := &c
result := pointer.ExtractPointer(d)
fmt.Println(result)
// Output:
// 1
}
```
### <span id="UnwarpOr">UnwarpOr</span>
<p>返回指针的值，如果指针为零值，则返回fallback。</p>
<b>函数签名:</b>
```go
UnwarpOr[T any](p *T, fallback T) T
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/mmNaLC38W8C)</span></b>
```go
package main
import (
"fmt"
"github.com/duke-git/lancet/v2/pointer"
)
func main() {
a := 123
b := "abc"
var c *int
var d *string
result1 := pointer.UnwarpOr(&a, 456)
result2 := pointer.UnwarpOr(&b, "abc")
result3 := pointer.UnwarpOr(c, 456)
result4 := pointer.UnwarpOr(d, "def")
fmt.Println(result1)
fmt.Println(result2)
fmt.Println(result3)
fmt.Println(result4)
// Output:
// 123
// abc
// 456
// def
}
```
### <span id="UnwarpOrDefault">UnwarpOrDefault</span>
<p>返回指针的值，如果指针为零值，则返回相应零值。</p>
<b>函数签名:</b>
```go
UnwarpOrDefault[T any](p *T) T
```
<b>示例:<span class="run-container">[运行](https://go.dev/play/p/ZnGIHf8_o4E)</span></b>
```go
package main
import (
"fmt"
"github.com/duke-git/lancet/v2/pointer"
)
func main() {
a := 123
b := "abc"
var c *int
var d *string
result1 := pointer.UnwarpOrDefault(&a)
result2 := pointer.UnwarpOrDefault(&b)
result3 := pointer.UnwarpOrDefault(c)
result4 := pointer.UnwarpOrDefault(d)
fmt.Println(result1)
fmt.Println(result2)
fmt.Println(result3)
fmt.Println(result4)
// Output:
// 123
// abc
// 0
//
}
```