Hi all -
I don't think there's any way to implement [list append] that doesn't require copying the list (tcl can do the append in place so doesn't have to do that). So building a list of length n requires a compute time on the order of n^2 - which gets to be problematic when n gets big.
Another alternative to arrays might be textfiles - however, there aren't yet very good methods for getting the data back out of them :)
Miller
On Wed, Mar 13, 2013 at 09:12:51AM -0700, Jonathan Wilkes wrote:
Hi list, Â Â Â Â See attached for difference between building a list of symbols through [list append] and building an array of symbols.
Now, I know the ds array resizing and setting is more efficient than building out a list using [list append], but I don't understand why the [list append] takes over a minute to complete. It can't be due to symbol table stuff since I'm using the same symbol over and over.
I know tcl lappend works fairly fast. Is there a way to speed up [list] stuff in Pd?
-Jonathan
#N struct wa array a word; #N struct word symbol s; #N canvas 588 135 450 506 10; #N canvas 0 0 450 300 word 0; #X obj 108 40 struct word symbol s; #X restore 332 25 pd word; #N canvas 0 0 450 300 wa 0; #X obj 40 40 struct wa array a word; #X restore 330 71 pd wa; #X scalar wa ; foo ; ;; #X obj 174 217 pointer; #X obj 134 300 setsize wa a; #X obj 89 335 element wa a; #X msg 62 305 symbol foo; #X obj 62 201 until; #X obj 62 161 t a b; #X msg 111 184 0; #X obj 62 235 f; #X obj 107 235 + 1; #X obj 107 257 t a a; #X obj 62 273 t b a; #X obj 62 366 set -symbol word s; #X obj 192 15 bng 33 250 50 0 empty empty do_it. 41 16 0 10 -262144 -1 -1; #X msg 174 140 traverse pd-dsresizing.pd , next; #X obj 311 312 until; #X obj 311 282 t a b; #X msg 371 313 bang; #X obj 311 334 list append; #X obj 311 356 list append foo; #X msg 311 260 45000; #X obj 247 261 realtime; #X obj 292 165 bng 33 250 50 0 empty empty do_it. 41 16 0 10 -262144 -1 -1; #X obj 292 203 t b b b; #X floatatom 247 283 8 0 0 0 - - -; #X obj 231 88 realtime; #X floatatom 231 110 8 0 0 0 - - -; #X obj 192 53 t b b b b; #X msg 62 139 45000; #X connect 3 0 4 1; #X connect 3 0 5 1; #X connect 5 0 14 1; #X connect 6 0 14 0; #X connect 7 0 10 0; #X connect 8 0 7 0; #X connect 8 1 9 0; #X connect 9 0 10 1; #X connect 10 0 11 0; #X connect 10 0 13 0; #X connect 11 0 12 0; #X connect 12 0 10 1; #X connect 12 1 4 0; #X connect 13 0 6 0; #X connect 13 1 5 0; #X connect 15 0 29 0; #X connect 16 0 3 0; #X connect 17 0 20 0; #X connect 18 0 17 0; #X connect 18 1 19 0; #X connect 19 0 20 1; #X connect 20 0 21 0; #X connect 21 0 20 1; #X connect 22 0 18 0; #X connect 23 0 26 0; #X connect 24 0 25 0; #X connect 25 0 23 1; #X connect 25 1 22 0; #X connect 25 2 23 0; #X connect 27 0 28 0; #X connect 29 0 27 1; #X connect 29 1 30 0; #X connect 29 2 16 0; #X connect 29 3 27 0; #X connect 30 0 8 0;
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