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Re: Concatenating arrays - speed issues? [message #76472 is a reply to message #76471]

Wed, 08 June 2011 02:48

rjp23
Messages: 97
Registered: June 2010

Member

On Jun 7, 5:42 pm, Craig Markwardt <craig.markwa...@gmail.com> wrote:
> What you are doing is the "IDL way" in the sense that it's a natural
> use of the concatenation feature of the language.
>
> But as you noticed, the performance degrades for lots of append
> operations.
>
> The next best way is to grow the array in chunks, and then fill in the
> chunks with available data. This forces you to keep track of the
> number of used elements in the array, separate from the array size.
> Once you fill the available chunk, only then do you add another
> chunk.
>
> This doesn't really get rid of the problem you noticed, but it does
> reduce the problem significantly. So, if each chunk has 1000
> elements, then the performance degradation is 1000x less. Then you
> can start to get fancy by growing the array with variable sized
> chunks.
>
> Craig

That might actually be quite a nice solution, it just means keeping
track with a few more counters.

I'll have a play and see how it goes :-)

Cheers

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[Message index]

		Re: Concatenating arrays - speed issues? By: Michael Galloy on Thu, 09 June 2011 04:55
		Re: Concatenating arrays - speed issues? By: rjp23 on Thu, 09 June 2011 04:35
		Re: Concatenating arrays - speed issues? By: penteado on Wed, 08 June 2011 05:05
		Re: Concatenating arrays - speed issues? By: Michael Galloy on Wed, 08 June 2011 04:55
		Re: Concatenating arrays - speed issues? By: rjp23 on Wed, 08 June 2011 02:48
		Re: Concatenating arrays - speed issues? By: rjp23 on Wed, 08 June 2011 02:46
		Re: Concatenating arrays - speed issues? By: penteado on Tue, 07 June 2011 11:20
		Re: Concatenating arrays - speed issues? By: ben.bighair on Tue, 07 June 2011 10:24
		Re: Concatenating arrays - speed issues? By: Craig Markwardt on Tue, 07 June 2011 09:42

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