将字节切片”[]uint8″转换为Go语言中的float64。

huangapple
go评论129阅读模式
英文:

Convert byte slice "[]uint8" to float64 in GoLang

问题

我正在尝试将一个[]uint8字节切片转换为Go语言中的float64类型。我在网上找不到解决这个问题的方法。我看到有建议先转换为字符串，然后再转换为float64，但这似乎不起作用，它会丢失其值，最终得到的是零。

示例：

  1. metric.Value, _ = strconv.ParseFloat(string(column.Value), 64)

但这并不起作用...

英文:

I'm trying to convert a []uint8 byte slice into a float64 in GoLang. I can't find a solution for this issue online. I've seen suggestions of converting to a string first and then to a float64 but this doesn't seem to work, it loses it's value and I end up with zeroes.

Example:

  1. metric.Value, _ = strconv.ParseFloat(string(column.Value), 64)

And it doesn't work...

答案1

得分: 67

例如，

  1. package main
  3. import (
  4.     "encoding/binary"
  5.     "fmt"
  6.     "math"
  7. )
  9. func Float64frombytes(bytes []byte) float64 {
  10.     bits := binary.LittleEndian.Uint64(bytes)
  11.     float := math.Float64frombits(bits)
  12.     return float
  13. }
  15. func Float64bytes(float float64) []byte {
  16.     bits := math.Float64bits(float)
  17.     bytes := make([]byte, 8)
  18.     binary.LittleEndian.PutUint64(bytes, bits)
  19.     return bytes
  20. }
  22. func main() {
  23.     bytes := Float64bytes(math.Pi)
  24.     fmt.Println(bytes)
  25.     float := Float64frombytes(bytes)
  26.     fmt.Println(float)
  27. }

输出：

  1. [24 45 68 84 251 33 9 64]
  2. 3.141592653589793
英文:

For example,

  1. package main
  3. import (
  4. 	"encoding/binary"
  5. 	"fmt"
  6. 	"math"
  7. )
  9. func Float64frombytes(bytes []byte) float64 {
  10. 	bits := binary.LittleEndian.Uint64(bytes)
  11. 	float := math.Float64frombits(bits)
  12. 	return float
  13. }
  15. func Float64bytes(float float64) []byte {
  16. 	bits := math.Float64bits(float)
  17. 	bytes := make([]byte, 8)
  18. 	binary.LittleEndian.PutUint64(bytes, bits)
  19. 	return bytes
  20. }
  22. func main() {
  23. 	bytes := Float64bytes(math.Pi)
  24. 	fmt.Println(bytes)
  25. 	float := Float64frombytes(bytes)
  26. 	fmt.Println(float)
  27. }

Output:

  1. [24 45 68 84 251 33 9 64]
  2. 3.141592653589793

答案2

得分: 6

我认为你正在寻找的是Go文档中的这个示例：
http://golang.org/pkg/encoding/binary/#example_Read

  1. var pi float64
  2. b := []byte{0x18, 0x2d, 0x44, 0x54, 0xfb, 0x21, 0x09, 0x40}
  3. buf := bytes.NewReader(b)
  4. err := binary.Read(buf, binary.LittleEndian, &pi)
  5. if err != nil {
  6.   fmt.Println("binary.Read failed:", err)
  7. }
  8. fmt.Print(pi)

打印结果为3.141592653589793。

英文:

I think this example from Go documentation is what you are looking for:
http://golang.org/pkg/encoding/binary/#example_Read

  1. var pi float64
  2. b := []byte{0x18, 0x2d, 0x44, 0x54, 0xfb, 0x21, 0x09, 0x40}
  3. buf := bytes.NewReader(b)
  4. err := binary.Read(buf, binary.LittleEndian, &pi)
  5. if err != nil {
  6.   fmt.Println("binary.Read failed:", err)
  7. }
  8. fmt.Print(pi)

Prints 3.141592653589793

答案3

得分: 6

根据评论所说，一切取决于你的[]uint8切片中包含的是什么类型的数据。

如果它是表示IEEE 754浮点数值的字节，采用Kluyg或peterSo的答案（后者性能更好，不使用反射）。

如果它是Latin-1/UTF-8编码的文本表示，则你应该能够像你刚才做的那样操作：

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"strconv"
  6. )
  8. func main() {
  9. 	var f float64
  10. 	text := []uint8("1.23") // 以Latin-1文本表示的十进制值
  12. 	f, err := strconv.ParseFloat(string(text), 64)
  13. 	if err != nil {
  14. 		panic(err)
  15. 	}
  17. 	fmt.Println(f)
  18. }

结果：

1.23

Playground: http://play.golang.org/p/-7iKRDG_ZM

英文:

As the comments read, it all depends on what kind of data you have in your []uint8 slice.

If it is bytes representing an IEEE 754 floating-point value in Little Endian order, then use Kluyg's or peterSo's (better performance without use of reflection) answer.

If it is a textual representation in Latin-1/UTF-8 encoding, then you should be able to do what you just did:

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"strconv"
  6. )
  8. func main() {
  9. 	var f float64
  10. 	text := []uint8("1.23") // A decimal value represented as Latin-1 text
  11. 	
  12. 	f, err := strconv.ParseFloat(string(text), 64)
  13. 	if err != nil {
  14. 		panic(err)
  15. 	}
  16. 	
  17. 	fmt.Println(f)
  18. }

Result:

>1.23

Playground: http://play.golang.org/p/-7iKRDG_ZM

答案4

得分: 2

我希望这个技巧能有所帮助。它的目的是将一长串二进制数转换为浮点数。

例如：
0110111100010010100000111100000011001010001000010000100111000000 -> -3.1415

  1. func binFloat(bin string) float64 {
  2.     var s1 []byte
  3.     var result float64
  5.     if len(bin) % 8 == 0 {
  6.         for i := 0; i < len(bin) / 8; i++ {
  7.             // 将字符串分割成长度为8的片段
  8.             // 将字符串转换为整数，再转换为字节
  9.             num, _ := strconv.ParseInt(bin[8*i: 8*(i + 1)], 2, 64)
  10.             // 将字节存入切片s1
  11.             s1 = append(s1, byte(num))
  12.         }
  13.     }
  15.     // 将字节切片转换为float64类型
  16.     // 下面的算法来自于golang二进制示例
  18.     buf := bytes.NewReader(s1)
  20.     // 你也可以将binary.LittleEndian改为binary.BigEndian
  21.     // 有关字节序的详细信息，请搜索字节序
  23.     err := binary.Read(buf, binary.LittleEndian, &result)
  25.     if err != nil {
  26.         panic(err)
  27.         fmt.Println("二进制长度不是8的倍数")
  28.     }
  30.     return result
  31. }
英文:

I hope this hack helps. The purpose of it is to convert the long stream of binary numbers to float.

For example:
0110111100010010100000111100000011001010001000010000100111000000 -> -3.1415

  1. func binFloat(bin string) float64 {
  3.     var s1 []byte
  4.     var result float64
  6.     if len(bin) % 8 == 0 {
  8.             for i := 0; i &lt; len(bin) / 8; i++ {
  10.                     //Chop the strings into a segment with a length of 8.
  11.                     //Convert the string to Integer and to byte
  13.                     num, _ := strconv.ParseInt(bin[8*i: 8*(i + 1)], 2, 64) 
  14.                     //Store the byte into a slice s1
  15.                     s1 = append(s1, byte(num)) 
  16.             }
  18.     }
  19.     
  20.     //convert the byte slice to a float64. 
  21.     //The algorithm below are copied from golang binary examples. 
  23.     buf := bytes.NewReader(s1)
  25.     //You can also change binary.LittleEndian to binary.BigEndian
  26.     //For the details of Endianness, please google Endianness
  27.   
  28.     err := binary.Read(buf, binary.LittleEndian, &amp;result) 
  30.     if err != nil {
  32.             panic(err)
  33.             fmt.Println(&quot;Length of the binary is not in the length of 8&quot;)
  34.     }
  36.     return result
  37. }

huangapple
  • 本文由 发表于 2014年3月19日 05:57:12
  • 转载请务必保留本文链接：https://go.coder-hub.com/22491876.html
  • arrays
  • go
  • uint8t
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