From 4bc43f3278cfac472dfb51370071f6b49e2136cb Mon Sep 17 00:00:00 2001
From: dudaodong <lanliddd.2007@163.com>
Date: Tue, 13 Jun 2023 14:59:30 +0800
Subject: [PATCH] feat: add Log

---
 docs/mathutil.md          | 65 ++++++++++++++++++++++++++++++---------
 docs/mathutil_zh-CN.md    | 61 ++++++++++++++++++++++++++++--------
 mathutil/mathutil.go      |  5 +++
 mathutil/mathutil_test.go |  8 +++++
 4 files changed, 112 insertions(+), 27 deletions(-)

diff --git a/docs/mathutil.md b/docs/mathutil.md
index 89fac08..b38f44d 100644
--- a/docs/mathutil.md
+++ b/docs/mathutil.md
@@ -37,6 +37,7 @@ import (
 -   [LCM](#LCM)
 -   [Cos](#Cos)
 -   [Sin](#Sin)
+-   [Log](#Log)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -363,20 +364,20 @@ import (
 
 func main() {
     result1 := mathutil.IsPrime(-1)
-	result2 := mathutil.IsPrime(0)
-	result3 := mathutil.IsPrime(1)
-	result4 := mathutil.IsPrime(2)
+    result2 := mathutil.IsPrime(0)
+    result3 := mathutil.IsPrime(1)
+    result4 := mathutil.IsPrime(2)
 
-	fmt.Println(result1)
-	fmt.Println(result2)
-	fmt.Println(result3)
-	fmt.Println(result4)
+    fmt.Println(result1)
+    fmt.Println(result2)
+    fmt.Println(result3)
+    fmt.Println(result4)
 
-	// Output:
-	// false
-	// false
-	// false
-	// true
+    // Output:
+    // false
+    // false
+    // false
+    // true
 }
 ```
 
@@ -458,7 +459,6 @@ func main() {
 }
 ```
 
-
 ### <span id="Cos">Cos</span>
 
 <p>Returns the cosine of the radian argument.</p>
@@ -501,7 +501,6 @@ func main() {
 }
 ```
 
-
 ### <span id="Sin">Sin</span>
 
 <p>Returns the sine of the radian argument.</p>
@@ -542,4 +541,40 @@ func main() {
     // 0
     // 1
 }
-```
\ No newline at end of file
+```
+
+### <span id="Log">Log</span>
+
+<p>Returns the logarithm of base n.</p>
+
+<b>Signature:</b>
+
+```go
+func Log(n, base float64) float64
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/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
+}
+```
diff --git a/docs/mathutil_zh-CN.md b/docs/mathutil_zh-CN.md
index 5c8800e..1f17f32 100644
--- a/docs/mathutil_zh-CN.md
+++ b/docs/mathutil_zh-CN.md
@@ -37,6 +37,7 @@ import (
 -   [LCM](#LCM)
 -   [Cos](#Cos)
 -   [Sin](#Sin)
+-   [Log](#Log)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -363,20 +364,20 @@ import (
 
 func main() {
     result1 := mathutil.IsPrime(-1)
-	result2 := mathutil.IsPrime(0)
-	result3 := mathutil.IsPrime(1)
-	result4 := mathutil.IsPrime(2)
+    result2 := mathutil.IsPrime(0)
+    result3 := mathutil.IsPrime(1)
+    result4 := mathutil.IsPrime(2)
 
-	fmt.Println(result1)
-	fmt.Println(result2)
-	fmt.Println(result3)
-	fmt.Println(result4)
+    fmt.Println(result1)
+    fmt.Println(result2)
+    fmt.Println(result3)
+    fmt.Println(result4)
 
-	// Output:
-	// false
-	// false
-	// false
-	// true
+    // Output:
+    // false
+    // false
+    // false
+    // true
 }
 ```
 
@@ -543,4 +544,40 @@ func main() {
     // 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:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/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
+}
 ```
\ No newline at end of file
diff --git a/mathutil/mathutil.go b/mathutil/mathutil.go
index 35bc1a7..fc3a2cf 100644
--- a/mathutil/mathutil.go
+++ b/mathutil/mathutil.go
@@ -189,3 +189,8 @@ func Cos(radian float64, precision ...int) float64 {
 func Sin(radian float64, precision ...int) float64 {
 	return Cos((math.Pi / 2) - radian)
 }
+
+// Log returns the logarithm of base n.
+func Log(n, base float64) float64 {
+	return math.Log(n) / math.Log(base)
+}
diff --git a/mathutil/mathutil_test.go b/mathutil/mathutil_test.go
index a10f5d0..7c23dd7 100644
--- a/mathutil/mathutil_test.go
+++ b/mathutil/mathutil_test.go
@@ -172,3 +172,11 @@ func TestSin(t *testing.T) {
 	assert.EqualValues(0, Sin(math.Pi))
 	assert.EqualValues(1, Sin(math.Pi/2))
 }
+
+func TestLog(t *testing.T) {
+	assert := internal.NewAssert(t, "TestLog")
+
+	assert.EqualValues(3, Log(8, 2))
+	assert.EqualValues(3, TruncRound(Log(27, 3), 0))
+	assert.EqualValues(2.32, TruncRound(Log(5, 2), 2))
+}