object[,] to object[] or object[][] to object[]

Question

I try the following. I got data in the following two-dimensioanl buffer array from 2 channels:

object[,] buffer;
buffer = new buffer[2,1000000];

Now i only want to extract one channel to an one-dimensional array.

object[] bufferdata = buffer(1,???);

Does somebody know an way to get those data in a new array WITHOUT copying each value of the buffer(1,i) in a loop. Iam also able to use this kind of two-dimensional array object[][] buffer. Maybe this is bestter to find a solution.

object[][] to object[] is straight (unless you want to object[m][]) but for object[,] you must copy — Adriano Repetti, Sep 30 '14 at 11:59
possible duplicate of [How to copy a row of values from a 2D array into a 1D array?](http://stackoverflow.com/questions/797354/how-to-copy-a-row-of-values-from-a-2d-array-into-a-1d-array) — James, Sep 30 '14 at 12:04
Thx, but my question also includes that maybe it is better to use kind of object[][] array to convert into an object[] array without copying. — REMberry, Sep 30 '14 at 12:16
If you want to do this without copying then you *have* to create an array of arrays. So it has to be object[][]. If you do it wrong with object[,] then copying is a hard requirement. — Hans Passant, Sep 30 '14 at 12:20
Yes, that was my question... I only want to copy the ref of the array to an other and not copying in a loop. — REMberry, Sep 30 '14 at 12:30
I use object as a sample array. I use arrays from type of double. — REMberry, Sep 30 '14 at 13:15

score 0 · Answer 1 · answered Sep 30 '14 at 13:16

Going from a 2D array object[,] to a 1D array object[] is always going to be slow. It helps if you don't use object and know what types are stored. Buffer.BlockCopy() wont help you because it only works with array of primitives only.

I suggest either storing the buffer in a jagged array object[][] per channel and then retrieval is trivial object[] data = buffer[i]

Or create a long 1D array of size 2*1000000 and layer the data by channel. Then you can use Array.Copy() or maybe Buffer.BlockCopy() if you know the types to move either the first 1000000 elements out, or the last 1000000 elements out.

object[,] to object[] or object[][] to object[]

1 Answers1