How do I convert an array of floats to a byte[] and back?
Solution 1:
If you're looking for performance then you could use Buffer.BlockCopy
. Nice and simple, and probably about as fast as you'll get in managed code.
var floatArray1 = new float[] { 123.45f, 123f, 45f, 1.2f, 34.5f };
// create a byte array and copy the floats into it...
var byteArray = new byte[floatArray1.Length * 4];
Buffer.BlockCopy(floatArray1, 0, byteArray, 0, byteArray.Length);
// create a second float array and copy the bytes into it...
var floatArray2 = new float[byteArray.Length / 4];
Buffer.BlockCopy(byteArray, 0, floatArray2, 0, byteArray.Length);
// do we have the same sequence of floats that we started with?
Console.WriteLine(floatArray1.SequenceEqual(floatArray2)); // True
Solution 2:
You are not moving the position when you copy the float[i] into the byte array, you should write something like
Array.Copy(BitConverter.GetBytes(float[i]),0,res,i*4);
instead of just:
ret = BitConverter.GetBytes(floats[i]);
the inverse function follow the same strategy.
Solution 3:
There's the BitConverter.ToSingle(byte[] value, int startIndex)
method that should help out here.
Returns a single-precision floating point number converted from four bytes at a specified position in a byte array.
Your probably want something like (untested):
static float[] ConvertByteArrayToFloat(byte[] bytes)
{
if(bytes == null)
throw new ArgumentNullException("bytes");
if(bytes.Length % 4 != 0)
throw new ArgumentException
("bytes does not represent a sequence of floats");
return Enumerable.Range(0, bytes.Length / 4)
.Select(i => BitConverter.ToSingle(bytes, i * 4))
.ToArray();
}
EDIT: Non-LINQ:
float[] floats = new float[bytes.Length / 4];
for (int i = 0; i < bytes.Length / 4; i++)
floats[i] = BitConverter.ToSingle(bytes, i * 4);
return floats;
Solution 4:
static float[] ConvertByteArrayToFloat(byte[] bytes)
{
if(bytes.Length % 4 != 0) throw new ArgumentException();
float[] floats = new float[bytes.Length/4];
for(int i = 0; i < floats.Length; i++)
{
floats[i] = BitConverter.ToSingle(bytes, i*4);
}
return floats;
}