如何有效地从双数组复制到字节数组 [英] How to efficiently copy from a double array to a byte array

问题描述

我正在尝试处理一个包含超过100万个条目的双数组，并尝试了下面列出的以下例程。但是我经历了很长的处理时间，例如1000点需要花费5分钟来处理。这是我为执行此任务而构建的代码片段。从double []转换为byte []时，是否有更有效的方法加速？





double [] val ;

byte [] rawDataByte = new byte [val.Rows];



for（int i = 0; i< val。行; i ++）

{



rawDataByte [i] =（byte）val.Vector [i];

}





先谢谢。

解决方案

作为谢尔盖告诉你，你展示的代码甚至不会编译，至少在C＃中。



最好，最有效的方法是使用缓冲区类。

  int  count =  10 ; 
  double  [] reals =  new   double < /跨度> [数]; 
随机r = 新 Random（）; 
  for （ int  i =  0 ; i <  count; i ++）{
 reals [i] = r.NextDouble（）*  2000000000 。 0 ; 
} 
 count<< =  3 ;  //  与count * = 8相同 - 因为double是64位，因此8字节 
  byte  [] result =  new   byte  [计数]; 
 Buffer.BlockCopy（实数， 0 ，结果， 0 ，count）; 

这会将双数组的核心位复制到字节数组，按 little endian order 。

如果需要它以big endian顺序，你需要：

- 在 Buffer.BlockCopy之后是否生成 result.Reverse（） （）。

- 或实现自己的复制功能。



缓冲区块块方法 [ ^ ]



请在发布问题之前，说实话，并显示一些实际编译代码。

我更喜欢Buffer.BlockCopy检查此链接

I'm trying to process a double array that has over 1 million entries and tried the following routine listed below. However I experienced a very long processing time, which for example a 1000 points took over 5 minutes to process. Here is a snippet of the code I have constructed to perform this task. Is there a more efficient way speed things up when converting from a double[] to a byte[]?


double[] val;
byte[] rawDataByte = new byte[val.Rows];

for (int i = 0; i < val.Rows; i++)
{

rawDataByte[i] = (byte)val.Vector[i];
}


Thanks In Advance.

解决方案

As Sergey told you, the code you show won't even compile, at least in C#.

The best, most efficient method is to use the Buffer class.

int count = 10;
double[] reals = new double[count];
Random r = new Random();
for (int i = 0; i < count; i++) {
   reals[i] = r.NextDouble() * 2000000000.0;
}
count <<= 3; // same as count *= 8 - because a double is 64 bits, thus 8 bytes
byte[] result = new byte[count];
Buffer.BlockCopy(reals, 0, result, 0, count);

This will copy the core bits of the double array to the byte array, in little endian order.
If you need it in big endian order, you need to:
- whether make a result.Reverse() after Buffer.BlockCopy().
- or implement your own copy function.

Buffer.BlockCopy Method[^]

Please, before posting a question, be honest and show some actually compiling code.

i would prefer Buffer.BlockCopy check this link

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