POV-Ray : Newsgroups : povray.general : dynamic memory possible? : Re: dynamic memory possible? Server Time
31 Jul 2024 10:29:18 EDT (-0400)
  Re: dynamic memory possible?  
From: digitalseraphim
Date: 4 Jun 2007 12:54:54
Message: <466443de$1@news.povray.org>
Warp wrote:
> Jim Charter <jrc### [at] msncom> wrote:
>> In arrays.inc there is a macro to resize an array.  So you can define 
>> you array initially to take the first item then resize it with each 
>> sucessful read from your file.
> 
>   This is not a good solution, especially if the amount of items is large.
> 
>   The resizing is done by creating a second array of the new size and
> then copying the elements of the first array into the second. If you do
> this for all n elements in the input you'll end up doing n resizes and
> n+(n-1)+(n-2)+...+1 copy operations, which grows proportional to the
> square of n. (For example if the input had 1000 elements it would end up
> making 500500 copy operations. That's half million.)
> 

but what you can do, is start out with a reasonable guess and increase 
it from there (by jumps).  You may end up wasting some space by growing 
the array too large, but it would work.

-ds


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