From 50a389bea35a91ddae1394c5d35a6f1c703f5bdd Mon Sep 17 00:00:00 2001 From: Hans-Christoph Steiner Date: Tue, 9 Mar 2004 03:51:28 +0000 Subject: Checked in Olaf's 1.5.2 sources. Here are the changes: v 1.5.2 (17. december 2003): - modified netclient for not to drop received data: use of syspollfn instead of clock to poll for incoming data, circular recv buffer v 1.5 (18. october 2003): - added some usefull features to arraycopy (i.e. copying just parts of an array and copying to specified position in destination array) - new object: nchange - IRIX 6.5 port (for GCC 3.3) - OS X binary (Jaguar 10.2.6) v 1.4 (22. may 2003): - updated sources to compile with Pd0.37-test4 - new object: arraycopy v 1.3 (12. april 2003): - new objects: sync listfifo - all setup routines renamed to maxlib__setup() to avoid name clashes, old names still work via class_addcreator() - some improvements for the help files svn path=/trunk/externals/maxlib/; revision=1394 --- help/automata.txt | 356 +++++++++++++++++++++++++++--------------------------- 1 file changed, 178 insertions(+), 178 deletions(-) (limited to 'help/automata.txt') diff --git a/help/automata.txt b/help/automata.txt index afa5e9e..3f5ff21 100644 --- a/help/automata.txt +++ b/help/automata.txt @@ -1,178 +1,178 @@ -[The following note originally appeared on the emusic-l mailing list. It is -reprinted here with the author's permission] - -From xrjdm@FARSIDE.GSFC.NASA.GOV Wed Nov 23 11:26:39 1994 -Date: Tue, 4 Oct 1994 15:09:23 -0500 -From: Joe McMahon -Reply to: Electronic Music Discussion List -To: Multiple recipients of list EMUSIC-L -Subject: Automata: the long-awaited summary - -Back in August, I think, I promised to post a quick intro to cellular -automata and how they can be used as a sound-generation tool. Since I'm -going to take a couple of different sources and sum them up with little or -no direct attribution, combined with my own opinions, I'll give everybody -my references *first* so they can delete the article and draw their own -conclusions if they so prefer. - -The primary reference that got me started on all this is one in the CMJ: -Vol 14, No. 4, Winter 1990: "Digital Synthesis of Self-modifying Waveforms -by Means of Cellular Automata" (Jacques Chareyon). Those who are already -familiar with automata may just skip to that article and forget about the -rest of this one. -Note: the article gives a mail address for M. Chareyon, but he did not -answer an inquiry about any available recordings using this technique in -1990. - -So. Anyone still here? Good. - -Cellular automata are a mathematical concept first introduced in the late -1940's. Generally speaking, a cellular automaton consists of a grid of -cells. Each cell may take on any of a number of values - binary automata -(cell on or cell off) are the most commonly studied. Each cell has a -neighborhood, defined more simply as other cells which influence its state. -The exact nature of this influence is defined by what are called transition -rules. The cellular automaton starts off with some cells in any of the -allowable states. for each "step" in the automaton's history, the -neighborhood of every cell is checked, and the state of the cell is -updated. All updates occur simultaneously. - -The transition rule must describe the resulting state of a cell for every -possible configuration of other cells in the neighborhood. For large -numbers of states, the amount of memory required to hold the transition -rule becomes increasingly large, Therefore, some automata use what is known -as a "totalistic" rule. These rules simply sum the values of the cells in -the neighborhood and then assign a result on this basis. The resulting -tables are far smaller. - -Many readers may already be familiar with John Horton Conway's game of -"Life". This is a two-dimensional binary automaton with a totalistic rule. -This makes for a very small rule set: - - i) If fewer than two filled cells (cells with value 1) surround a cell, - it becomes empty next generation. - ii) If more than three filled cells surround a cell, it becomes empty - next generation. -iii) If exactly three cells filled cells surround a cell, it becomes - filled on the next generation. - -This corresponds to a totalistic rule set with a total of 8(2-1)+1 or 9 -rules (one each for the sum values of 0 (no cells with a value) through 9 -(all cells with a value) ).If the transition rule were represented as a -non-totalistic one, the rule set would need 2**8 or 256 entries. There are -many interesting totalistic automata, so giving up detailed description of -every nuance of the transitions to save memory space isn't a big sacrifice. - -Interesting as two dimensional automata are, they really aren't terribly -useful for music making. There have been some experiments which have -attempted to use a two-dimensional automaton to generate MIDI events - -synthesis at the note level, using : - -Battista, T. and M. Giri, 1988. "Composizione Tramite Automi Cellulari." -Atti del VII Cooloquio di Informatica Musicale. Rome, Italy: Edizione Arti -Grafiche Ambrosini, pp. 181-182. - -Edgar, R. and J. Ryan, 1986. "LINA" Exhibition of the 1986 International -Computer Music Conference, San Francisco: Computer Music Association. - -I have not heard any of the music from these efforts, so I certainly can't -pass any judgement on them. For the purposes of this summary, we'll just -look at one-dimensional automata. These use a linear array of cells, with -the neighborhood generally being one or two cells on either side of each -cell. -(This is the type of automaton dealt with in M. Chareyon's article, which I -will be paraphrasing broadly hereafter). - -M. Chareyon's automata are wavetables. A digitized signal is stored as a -linear array of numbers in memory. A totalistic rule is used to determine a -lookup value which indexes into an array containing the resulting value; -this is saved into a second array. After the first array is completely -processed, the roles of the two are swapped and the process is repeated. - -The limiting factor in this process is the number of bits of resolution -being used to generate the sound. For a totalistic rule using a two-cell -neighborhood and 12-bit individual samples, we have 3*(2*12) = 12288 -entries in the rule table. At 2 bytes each, this is 24K of storage. If we -go to 16-bit sample resolution, we have 196608 entries at 2 bytes each for -a total of 393216 bytes, or 384K. - -The key point of M. Charyeon's method is the use of small neighborhoods -with large numbers of cellular states. Since the computation of the new -wavetable is all table lookup, very complex transition rules can be -precomputed and loaded into the tables, allowing the synthesis to -essentially be a fast sum-and-lookup loop to calculate each new wavesample. ->From the article, it appears that M. Chareyon was able to produce 2 or 3 -voices in realtime on a Mac II with a Digidesign Sound Accelerator board. -It seems that it would probably be possible to use an AV Mac to do it -without the board. - -This LASy (Linear Automaton Synthesis) method is closely related to the -Karplus-Strong plucked-string algorithm, in that a wavesample is run -through an algorithm which recirculates the samples to "self-modify" the -wave. In fact, a judicious choice of table entries allows one to very -simply simulate the K-S algoritm directly. - -So what are the sounds like? Some automata produce waveforms which quickly -"ramp-up" to complex spectra and then drop off quickly. Others move to a -steady state and then remain there. Yet others produce never-ending and -unpredictable waveforms, whose harmonic content is constantly changing. - -Obviously enough, the original wavesample can be obtained mathematically, -or by actual sampling and using LASy as a waveshaper. As M. Chareyon notes, -a quick estimate of the number of possible automata for a 2-neighbor -totalistic rule using a 256-entry wavetable with 12-bit entries is -(2**12)**256 * (2**12)**(3*2**12) or about 10**4500 possible automata. Of -course, many, many of these would not be suitable for music (e.g., the 4096 -automata in which all values go to one vlaue in one step, etc.); however, -the number of musically useful automata is still likely to be an immense -number. - -M. Chareyon provides a number of examples of ways to fill out the rule -tables and a number of hints on creating wave tables - generally speaking, -one can create a function which is used to compute the values to be placed -into the table and then fill it so it can simply be loaded and used by the -basic algorithm. His experience in using LASy is that he manages -approximately 50% of the time to produce sounds with the desired -characteristics, and that about 10% of the remaining time he gets -unexpected but useful results which can be used as starting points for -further exploration. - -Again, the important point is that the basic automaton uses wavesamples at -full resolution, calculating a new wavesample for each step of the -automaton; the next wavesample can be played while the new one is being -calculated. Because of the large number of states, mathematical tools for -the analysis of automata and the construction of automata with specifically -desired qualities require too much storage and compute time to make them -useful for LASy purposes. - -Again, much of this article is paraphrased from M. Chareyon's article; I -take no credit for any of the work in this note. I'm just summarizing. - -The following other articles were referenced by M. Chareyon's article: - -Burks, A., ed. 1970. Essays on Cellular Automata. Champaign/Urbana, IL: -University of Illinois Press. - -Chareyon, J. 1988a. "Sound Synthesis and Processing by Means of Linear -Cellular Automata." Proceedings of the 1988 Internation Computer Music -Conference. San Francisco: Computer Music Association. - -Chareyon, J. 1988b. "Wavetable come Automa Cellulare: una Nuova Tecnica di -Sintesi." Atti del VII Colloquio di Informatica Musicale, Rome, Italy: -Edizioni Arti Grafiche Ambrosini, pp. 174-177. - -Farmer, D., T. Toffoli, and S. Wolfram, eds. 1984. Cellular Automata. -North-Holland Physics Publishing. [One of the definitive works on cellular -automata - fairly heavy math, not a popular presentation - JM] - -Gardner, M. 1970. "The Fantastic Combinations of John Conway's New Solitare -Game 'Life'". Scientific American 223(4) 120-123. [A good introduction to -cellular automata, focusing on 'life' in specific. Useful intro if my -1-paragraph summary of automata was confusing :) - JM] - - --- Joe M. - --- -"At the end of the hour, we'll have information on the sedatives used by -the artists,,," (MST3K) - +[The following note originally appeared on the emusic-l mailing list. It is +reprinted here with the author's permission] + +From xrjdm@FARSIDE.GSFC.NASA.GOV Wed Nov 23 11:26:39 1994 +Date: Tue, 4 Oct 1994 15:09:23 -0500 +From: Joe McMahon +Reply to: Electronic Music Discussion List +To: Multiple recipients of list EMUSIC-L +Subject: Automata: the long-awaited summary + +Back in August, I think, I promised to post a quick intro to cellular +automata and how they can be used as a sound-generation tool. Since I'm +going to take a couple of different sources and sum them up with little or +no direct attribution, combined with my own opinions, I'll give everybody +my references *first* so they can delete the article and draw their own +conclusions if they so prefer. + +The primary reference that got me started on all this is one in the CMJ: +Vol 14, No. 4, Winter 1990: "Digital Synthesis of Self-modifying Waveforms +by Means of Cellular Automata" (Jacques Chareyon). Those who are already +familiar with automata may just skip to that article and forget about the +rest of this one. +Note: the article gives a mail address for M. Chareyon, but he did not +answer an inquiry about any available recordings using this technique in +1990. + +So. Anyone still here? Good. + +Cellular automata are a mathematical concept first introduced in the late +1940's. Generally speaking, a cellular automaton consists of a grid of +cells. Each cell may take on any of a number of values - binary automata +(cell on or cell off) are the most commonly studied. Each cell has a +neighborhood, defined more simply as other cells which influence its state. +The exact nature of this influence is defined by what are called transition +rules. The cellular automaton starts off with some cells in any of the +allowable states. for each "step" in the automaton's history, the +neighborhood of every cell is checked, and the state of the cell is +updated. All updates occur simultaneously. + +The transition rule must describe the resulting state of a cell for every +possible configuration of other cells in the neighborhood. For large +numbers of states, the amount of memory required to hold the transition +rule becomes increasingly large, Therefore, some automata use what is known +as a "totalistic" rule. These rules simply sum the values of the cells in +the neighborhood and then assign a result on this basis. The resulting +tables are far smaller. + +Many readers may already be familiar with John Horton Conway's game of +"Life". This is a two-dimensional binary automaton with a totalistic rule. +This makes for a very small rule set: + + i) If fewer than two filled cells (cells with value 1) surround a cell, + it becomes empty next generation. + ii) If more than three filled cells surround a cell, it becomes empty + next generation. +iii) If exactly three cells filled cells surround a cell, it becomes + filled on the next generation. + +This corresponds to a totalistic rule set with a total of 8(2-1)+1 or 9 +rules (one each for the sum values of 0 (no cells with a value) through 9 +(all cells with a value) ).If the transition rule were represented as a +non-totalistic one, the rule set would need 2**8 or 256 entries. There are +many interesting totalistic automata, so giving up detailed description of +every nuance of the transitions to save memory space isn't a big sacrifice. + +Interesting as two dimensional automata are, they really aren't terribly +useful for music making. There have been some experiments which have +attempted to use a two-dimensional automaton to generate MIDI events - +synthesis at the note level, using : + +Battista, T. and M. Giri, 1988. "Composizione Tramite Automi Cellulari." +Atti del VII Cooloquio di Informatica Musicale. Rome, Italy: Edizione Arti +Grafiche Ambrosini, pp. 181-182. + +Edgar, R. and J. Ryan, 1986. "LINA" Exhibition of the 1986 International +Computer Music Conference, San Francisco: Computer Music Association. + +I have not heard any of the music from these efforts, so I certainly can't +pass any judgement on them. For the purposes of this summary, we'll just +look at one-dimensional automata. These use a linear array of cells, with +the neighborhood generally being one or two cells on either side of each +cell. +(This is the type of automaton dealt with in M. Chareyon's article, which I +will be paraphrasing broadly hereafter). + +M. Chareyon's automata are wavetables. A digitized signal is stored as a +linear array of numbers in memory. A totalistic rule is used to determine a +lookup value which indexes into an array containing the resulting value; +this is saved into a second array. After the first array is completely +processed, the roles of the two are swapped and the process is repeated. + +The limiting factor in this process is the number of bits of resolution +being used to generate the sound. For a totalistic rule using a two-cell +neighborhood and 12-bit individual samples, we have 3*(2*12) = 12288 +entries in the rule table. At 2 bytes each, this is 24K of storage. If we +go to 16-bit sample resolution, we have 196608 entries at 2 bytes each for +a total of 393216 bytes, or 384K. + +The key point of M. Charyeon's method is the use of small neighborhoods +with large numbers of cellular states. Since the computation of the new +wavetable is all table lookup, very complex transition rules can be +precomputed and loaded into the tables, allowing the synthesis to +essentially be a fast sum-and-lookup loop to calculate each new wavesample. +>From the article, it appears that M. Chareyon was able to produce 2 or 3 +voices in realtime on a Mac II with a Digidesign Sound Accelerator board. +It seems that it would probably be possible to use an AV Mac to do it +without the board. + +This LASy (Linear Automaton Synthesis) method is closely related to the +Karplus-Strong plucked-string algorithm, in that a wavesample is run +through an algorithm which recirculates the samples to "self-modify" the +wave. In fact, a judicious choice of table entries allows one to very +simply simulate the K-S algoritm directly. + +So what are the sounds like? Some automata produce waveforms which quickly +"ramp-up" to complex spectra and then drop off quickly. Others move to a +steady state and then remain there. Yet others produce never-ending and +unpredictable waveforms, whose harmonic content is constantly changing. + +Obviously enough, the original wavesample can be obtained mathematically, +or by actual sampling and using LASy as a waveshaper. As M. Chareyon notes, +a quick estimate of the number of possible automata for a 2-neighbor +totalistic rule using a 256-entry wavetable with 12-bit entries is +(2**12)**256 * (2**12)**(3*2**12) or about 10**4500 possible automata. Of +course, many, many of these would not be suitable for music (e.g., the 4096 +automata in which all values go to one vlaue in one step, etc.); however, +the number of musically useful automata is still likely to be an immense +number. + +M. Chareyon provides a number of examples of ways to fill out the rule +tables and a number of hints on creating wave tables - generally speaking, +one can create a function which is used to compute the values to be placed +into the table and then fill it so it can simply be loaded and used by the +basic algorithm. His experience in using LASy is that he manages +approximately 50% of the time to produce sounds with the desired +characteristics, and that about 10% of the remaining time he gets +unexpected but useful results which can be used as starting points for +further exploration. + +Again, the important point is that the basic automaton uses wavesamples at +full resolution, calculating a new wavesample for each step of the +automaton; the next wavesample can be played while the new one is being +calculated. Because of the large number of states, mathematical tools for +the analysis of automata and the construction of automata with specifically +desired qualities require too much storage and compute time to make them +useful for LASy purposes. + +Again, much of this article is paraphrased from M. Chareyon's article; I +take no credit for any of the work in this note. I'm just summarizing. + +The following other articles were referenced by M. Chareyon's article: + +Burks, A., ed. 1970. Essays on Cellular Automata. Champaign/Urbana, IL: +University of Illinois Press. + +Chareyon, J. 1988a. "Sound Synthesis and Processing by Means of Linear +Cellular Automata." Proceedings of the 1988 Internation Computer Music +Conference. San Francisco: Computer Music Association. + +Chareyon, J. 1988b. "Wavetable come Automa Cellulare: una Nuova Tecnica di +Sintesi." Atti del VII Colloquio di Informatica Musicale, Rome, Italy: +Edizioni Arti Grafiche Ambrosini, pp. 174-177. + +Farmer, D., T. Toffoli, and S. Wolfram, eds. 1984. Cellular Automata. +North-Holland Physics Publishing. [One of the definitive works on cellular +automata - fairly heavy math, not a popular presentation - JM] + +Gardner, M. 1970. "The Fantastic Combinations of John Conway's New Solitare +Game 'Life'". Scientific American 223(4) 120-123. [A good introduction to +cellular automata, focusing on 'life' in specific. Useful intro if my +1-paragraph summary of automata was confusing :) - JM] + + --- Joe M. + +-- +"At the end of the hour, we'll have information on the sedatives used by +the artists,,," (MST3K) + -- cgit v1.2.1