[PD] list-sort

[Matt Barber]

Also, I find it extremely tempting to think of a list of numbers as an
array[ ], but this analogy won't hold because you can't operate on the
list in-place -- I'm sure a lot of the overhead is in feeding entire
lists back and forth and around to the different parts of the patches.
 Maybe the algorithm with the fewest total [list] operations sometimes
wins out over the algorithm that's in general more efficient.

Matt



On Tue, Dec 2, 2008 at 10:01 PM, Matt Barber <brbrofsvl at gmail.com> wrote:
> For what it's worth,
>
> I just ran one possible benchmark on the [list-*sort] abstractions
> submitted recently, using [list-random] and [realtime].
>
> I think overall the overhead for [list-sort] is much less than for
> [list-shellsort] -- for short lists (<100) it takes about half the
> time.  [list-shellsort] is a bit quicker when the variance of the
> elements is smaller (which makes sense because the more alike the
> elements are the less the innermost loop will have to run) -- but
> [list-sort] still beats it.  I have a feeling that some of the
> overhead in [list-shellsort] is in the [list-swap] function and other
> list-abs objects, which are a little too feature-rich and/or
> idiot-proof for this particular use.  =o)
>
>
> However, after some trial and error with [list-sort] I found I am
> unable to sort a list of more than exactly 121 elements without
> freezing Pd -- 122 and up will freeze it.  This is because the main
> loop is not controlled with an [until] -- I think you can see the
> structure of [list-drip] for similar reasoning (the [until] is not
> "needed" logically, but helps with long lists to do it in steps).
> After implementing the [until] loop, I found that [list-sort] is even
> quicker than before, but the efficiency of the [list-shellsort]
> algorithm take over for list sizes >450 -- above that [list-shellsort]
> is substantially quicker (and quicker yet if the variance is low).  It
> beats [list-sort] by half for a list about 1300-1400 elements long or
> so (but not within reason -- it still takes about 2 seconds!).
>
>
> I attached the new [list-sort] and the goofy little diagnostic.
>
> Matt
>
>
>> Date: Tue, 2 Dec 2008 13:59:08 +0100
>> From: Frank Barknecht <fbar at footils.org>
>> Subject: Re: [PD] list-sort
>> To: pd-list at iem.at
>> Message-ID: <20081202125908.GJ18987 at fliwatut.scifi>
>> Content-Type: text/plain; charset="us-ascii"
>>
>> Hallo,
>>
>> oh, and I also now committed two more abstractions that Matt Barber
>> sent me offlist, of which one is a sorting abstraction as well. Matt's
>> [list-shellsort] uses the Shell sorting algorithm:
>> http://en.wikipedia.org/wiki/Shell_sort which generally is a bit
>> faster than insertion sort, but I didn't benchmark the two Pd
>> implementations (the speed in Pd of course also depends on how much
>> element shuffling and list-dripping is needed)
>>
>> Anyway, currently list-shellsort only does ascending sorting, so I
>> just decided to include both Michal's list-sort, which probably is
>> easier to understand, and Matt's list-shellsort in the current SVN's
>> [list]-abs collection. Choose your poison. ;)
>>
>> Ciao
>> --
>> Frank
>>
>> Michal Seta hat gesagt: // Michal Seta wrote:
>>
>>> Hi all,
>>>
>>> It is amazing how we take things for granted.  Most programming
>>> languages provide some sort of list sorting function/method.
>>> Surprisingly (or not) pd does not (or my search skills are null, or I
>>> am not bleeding edge enough).  I needed a solution that works with a
>>> vanilla pd.
>>>
>>> I was almost going to do the academia move and announce a pd exam, and
>>> have little pd-bees come up with a solution but I needed it *now* else
>>> I would not sleep or have terrible nightmares.  So here it is.  Thank
>>> heavens (but give your offerings to fbar's footils shrine) for
>>> list-abs.
>>>
>>> Busy pd-bees, should you care to improve on my solution, please be my
>>> guest, I am sure there are better ways of accomplishing this trivial
>>> task.  In any case, go forth and sort the world around (or within)
>>> you.
>>>
>>> ./MiS
>