Comments on: Sorting Vectors

By: Vector Sortierindex - Flashforum

Vector Sortierindex - Flashforum — Thu, 17 Feb 2011 01:41:08 +0000

[...] hilft evtl.: Sorting Vectors JacksonDunstan.com Ob Vectors immer so sinnvoll ist, gerade bzgl. Sortierung ist inbegriffen. __________________ [...]

By: jackson

jackson — Thu, 29 Jul 2010 17:30:45 +0000

This post was about a year old and needed some updating to my new performance article format, so I did that and took the opportunity to integrate your suggestion (also the suggestion of jloa above). While your approach does create a large Array that the garbage collector may have to collect, it's possible to have this pre-allocated and re-used so as to avoid the penalty. Under those conditions—where we don't have to count the GC time—your approach is about 2x faster than Vector.sort(), the next-fastest Vector sorting approach. Thanks for the tip!

By: bwhiting

bwhiting — Thu, 29 Jul 2010 13:26:33 +0000

have you tried just using an array for the sort then using that to build your vector?

http://blog.bwhiting.co.uk/?p=34

By: jackson

jackson — Thu, 13 May 2010 19:01:18 +0000

It’s not really fair to compare the generalized indexOf that works with all arrays to a function that works only with sorted arrays. For example, it’d be just as unfair if I made a search function that only worked with arrays that only have two elements:

function search(a:Array, val:*): int
{
    return a[0] == val ? 0 : (a[1] == val ? 1 : -1);
}

I’m sure that’s much faster than the binary search or indexOf… as long as you meet the special conditions. But that doesn’t mean I’ve “beaten” the native code.

By: eco_bach

eco_bach — Thu, 13 May 2010 14:32:25 +0000

Jack
when you say ‘You simply can’t beat native code with ActionScript, ‘ I disagree. I the case of searching a large array with indexOf() vs a binary search, I believe the latter is always faster(as long as the array is sorted first).
http://stackoverflow.com/questions/1987163/binary-search-from-java-to-actionscript

By: jackson

jackson — Wed, 07 Apr 2010 21:35:31 +0000

In practice the Vector would probably not be local to the function but instead stored long-term as a field of an object. Even so, System.gc() only works in the debug version of Flash Player, which most people don't have installed. As for caring about performance, it's true that most Flash apps won't care much about 1000 elements of a Vector, but larger, more resource-intensive ones can't afford to ignore that kind of extra memory usage in many places before the app is too heavy for some users.

By: jloa

jloa — Wed, 07 Apr 2010 17:29:41 +0000

Well, all you have to do is to call the System.gc after the sorting operation, the gc will clean up the memory as the array is local-based.
Speaking of performance, nope, sincerely, i haven’t tested the performance, but still if you r making a web site and have a vector of 1000 elements eg will u care about the performance? :)
Yeap, i will test it and post the results.

By: jackson

jackson — Wed, 10 Mar 2010 02:25:43 +0000

For CPU and memory performance. Converting to a temporary Array requires twice the memory and creates garbage to be collected right away. I can’t imagine it’s a very fast solution either, even disregarding the allocation and GC time. Have you performance tested it?

By the way, you could improve the performance of your implementation by using the new Array(size) constructor since you know how much many elements you need before doing the copy.

By: jloa

jloa — Tue, 09 Mar 2010 17:30:23 +0000

omg, guys, why do u complicate yr life with such code?! O_O.

To do a Vector.sortOn u need only 5 code lines.
http://chargedweb.com/labs/2010/02/20/vector-sorton/

By: Valentin

Valentin — Sat, 31 Oct 2009 09:26:30 +0000

Array sort is indeed much slower than manual sort functions implementations on numbers.