This is still much slower than [list-drip], and it freezes Pd for me when I get up to lists of n=100,000 or so. I think it's because Pd has to copy the list to an output every cycle of [until], so when n=10, you're only outputting something of size 10 10 times, but that grows by n^2 so when it's n=10,000 times 10,000 outputs, it's a lot. 1,000,000 seems impossible unless the list decreases in size each cycle, which it does in [list-drip], recursively.
On Sun, Oct 4, 2015 at 2:48 PM, Miller Puckette <[email protected]> wrote: > Here's a way to serialize a list in (I believe) linear time: > > #N canvas 881 291 450 300 10; > #X msg 136 14 list 3 . 1 4 1 5 9; > #X obj 83 97 list length; > #X obj 77 211 list split; > #X obj 101 186 list; > #X obj 139 55 t l b l; > #X obj 83 119 until; > #X obj 83 141 f; > #X obj 114 142 + 1; > #X msg 166 117 0; > #X obj 83 163 t b f; > #X obj 117 278 print; > #X obj 116 250 list split 1; > #X connect 0 0 4 0; > #X connect 1 0 5 0; > #X connect 2 1 11 0; > #X connect 3 0 2 0; > #X connect 4 0 1 0; > #X connect 4 1 8 0; > #X connect 4 2 3 1; > #X connect 5 0 6 0; > #X connect 6 0 7 0; > #X connect 6 0 9 0; > #X connect 7 0 6 1; > #X connect 8 0 6 1; > #X connect 9 0 3 0; > #X connect 9 1 2 1; > #X connect 11 0 10 0; > > cheers > Miller > > On Sun, Oct 04, 2015 at 02:27:37PM -0400, Matt Barber wrote: > > Your [pd drip] does a lot of extra work. It's go basically linear stack > > performance, and you're recopying the list every loop (an until loop > would > > solve this for a little extra cpu time). The secret of [list-drip] is > that > > it doesn't recopy the list using the [list] object, and it avoids stack > > overflows by doing the recursion split at the midpoint of the list and > only > > outputting when it's done the binary split down to lists of size 1, which > > are the elements, or size zero, which are bangs (and which are filtered > > out). > > > > Since it's binary recursion on the list, the stack only grows > > proportionally to log_2(n), which is about 20 for n=1,000,000. It's still > > going to be slower than an object written in C that can just iterate over > > the contents in a single loop, and lists in Pd are slower in general than > > arrays, so an until loop and tabread over an array is going to be > quicker. > > It is much slower for copying though -- an until loop with tabread and > > tabwrite has way more overhead than an [array get]-[array set] pair. > > > > > > On Sun, Oct 4, 2015 at 1:06 PM, Christof Ressi <[email protected]> > > wrote: > > > > > Please don't use the previous version of the multi-dimensional > arrays!!! > > > First, I forget to get rid of one [drip] object. Second, I discovered > that > > > [pd drip] will create a stack overflow if there are more than ca. 300 > > > elements! (Why???) So I replaced it with [list-drip] which works fine. > > > > > > So here's the corrected pure vanilla version + a zexy version using > > > [drip]. I prefer to use the latter one because it's waaaaay faster > than all > > > the drip abstractions based on [list split]. > > > > > > Vanilla: > https://www.dropbox.com/s/wd0avxtaneqgdic/carray_vanilla.zip?dl=0 > > > Zexy: https://www.dropbox.com/s/ea8kihwbdqhcajr/carray_zexy.zip?dl=0 > > > > > > Christof > > > > > > PS: I did a benchmark test of iterating through an array of 1 million > > > elements, using [realtime], and here's what I found on my system: > > > > > > [array get] + [drip] --> ca. 6.5-9ms > > > [until] + [tabread] --> ca. 120-200ms > > > [array get] + [list-drip] --> ca. 340-400ms > > > > > > To me this result was a bit surprising... > > > > > > You can test yourself with the attached patch. > > > *Gesendet:* Sonntag, 04. Oktober 2015 um 17:32 Uhr > > > *Von:* "Christof Ressi" <[email protected]> > > > *An:* "Matt Barber" <[email protected]> > > > > > > *Cc:* Pd-List <[email protected]> > > > *Betreff:* Re: [PD] array-abs > > > Wow, looks cool! > > > > > > Just a few days ago I reworked some of my personal table abstractions, > > > which also make use of the [array] object. However, some of them > depend on > > > zexy externals (I hope I didn't miss any other dependencies). I haven't > > > shared them yet so the documentation is quite poor (no help files, docs > > > inside the abstraction) and they look a bit messy. But maybe you can > get > > > some inspiration for your library... > > > https://www.dropbox.com/s/xvj031korqw8guf/ctab-abs.zip?dl=0 > > > > > > Additionally I've been working on three basic abstractions for > creating, > > > setting and reading multi-dimensional arrays of any number of > dimensions. > > > They are pure vanilla style and even come with a help file :-D. (a > object > > > for array resizing is yet to be done...) > > > https://www.dropbox.com/s/6xfgdyt697138e6/carray.zip?dl=0 > > > > > > Would be cool to hear your opinion on the multi-dimensional array > stuff! > > > > > > Christof > > > > > > > > > > > > > > > *Gesendet:* Samstag, 03. Oktober 2015 um 22:32 Uhr > > > *Von:* "Matt Barber" <[email protected]> > > > *An:* "IOhannes m zmölnig" <[email protected]> > > > *Cc:* Pd-List <[email protected]> > > > *Betreff:* Re: [PD] array-abs > > > Thanks. > > > > > > Yes. Right now I'm just looking to see if these would be useful, if > > > there's anything awful about the syntax, if they try to do too much or > are > > > too fussy, if anyone would want to contribute, etc. When I get them > > > polished a bit I'll do a regular release on the normal channels (I > can't > > > remember if I have access to anything officially Pd related). > > > > > > Matt > > > > > > On Sat, Oct 3, 2015 at 4:22 PM, IOhannes m zmölnig <[email protected]> > > > wrote: > > >> > > >> hi, > > >> > > >> great! > > >> > > >> On 10/03/2015 07:36 PM, Matt Barber wrote: > > >> > > > >> > https://www.dropbox.com/s/45tk62dpz0z2mqo/array-abs.zip?dl=0 > > >> > > > >> > > >> db? > > >> > > >> would you like to put those on a version control system of sorts, e.g. > > >> the puredata svn or some publicly available git repository (e.g. > github)? > > >> > > >> (read as: please let us not go back to the dark ages, where code was > > >> shared by sending files around by on floppy disks and you never new > > >> which version was the current one) > > >> > > >> fgmards > > >> IOhannes > > >> > > >> > > >> > > >> _______________________________________________ > > >> [email protected] mailing list > > >> UNSUBSCRIBE and account-management -> > > >> http://lists.puredata.info/listinfo/pd-list > > >> > > > > > > _______________________________________________ [email protected] > > > mailing list UNSUBSCRIBE and account-management -> > > > http://lists.puredata.info/listinfo/pd-list > > > _______________________________________________ [email protected] > > > mailing list UNSUBSCRIBE and account-management -> > > > http://lists.puredata.info/listinfo/pd-list > > > > > > _______________________________________________ > > [email protected] mailing list > > UNSUBSCRIBE and account-management -> > http://lists.puredata.info/listinfo/pd-list > >
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