November 2008 - chuck-users - lists.cs.princeton.edu

question about implementing a UANA
by Dexter J. Doyle 22 Nov '08

22 Nov '08

I've been working on implementing a pitch detector as a UANA in ChucK and I am basing it off code for a pitch detector that is written in C. I've been editing the file, uana_extract.cpp and wanted to see if there is a way to handle shorts and longs and their respective arrays since ChucK only has int and float. Dexter

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Re: [chuck-users] Mixing associative with integer indexed arrays? (multiple BUGS)
by Kassen 22 Nov '08

22 Nov '08

Hi, Stephen! 2008/11/22 Stephen Sugden <glurgle(a)gmail.com> > Is it possible to mix both types of array keys? Yes... or at least it *should* be.... ;¬) > The code I below works fine until I try to access any elements of the > array, then I get an ArrayOutofBounds exception. I corrected the lack of a type for "melodies". Then I had a hard time with it, as it turns out that this; [ 0, 2, 4, 5, 7, 9, 11, 12 ] @=> int melodies[0]; crashes ChucK. That's a bug, and it's good that we accidentally found it but kindly try to avoid such confusion by making sure the code you send works as you described. Right, on to the business at hand; > <<< scales["just"][0] >>>; > > You can't print the contents of a array (which this refers to) in one swoop like this, I fear. If you'd like to do this you'd have to loop over the array, if they all need to be on the same line and the length of the array is dynamic I think you'll have to join all elements together in a string and print that. Let's look at a version that should work properly; //=========================== float scales[0][0][0]; [ 0, 2, 4, 5, 7, 9, 11, 12 ] @=> int melodies[]; [ [1.0, 1.0], [16.0, 15.0], [9.0, 8.0], [6.0, 5.0], [5.0, 4.0], [4.0, 3.0], [7.0,5.0], [3.0, 2.0], [8.0,5.0], [5.0, 3.0], [7.0, 4.0], [15.0, 8.0], [2.0, 1.0] ] @=> scales["just"]; float et[13][2]; for(0 => int i; i <= 12; ++i){ 1.0 => et[i][0]; Math.pow(2.0, i / 12.0) => et[i][1]; } et @=> scales["equalTempered"]; for(int n; n< scales["just"][0].cap(); n++) { //goes out of bound for n==0 already <<<scales["just"][0][n]>>>; } //================== So... that's a bug, yes, and clearing out the associative indexes in favour of ints makes it go away. Good catch! If you'd like; add it to the Wiki here; http://wiki.cs.princeton.edu/index.php/ChucK/Bugs/Release Yours, Kas.

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Mixing associative with integer indexed arrays?
by Stephen Sugden 21 Nov '08

21 Nov '08

Is it possible to mix both types of array keys? The code I below works fine until I try to access any elements of the array, then I get an ArrayOutofBounds exception. The snippet is pretty short and I would hope it's self evident what I'm trying do with it. float scales[0][0][0]; [ 0, 2, 4, 5, 7, 9, 11, 12 ] @=> melodies[0]; [ [1.0, 1.0], [16.0, 15.0], [9.0, 8.0], [6.0, 5.0], [5.0, 4.0], [4.0, 3.0], [7.0,5.0], [3.0, 2.0], [8.0,5.0], [5.0, 3.0], [7.0, 4.0], [15.0, 8.0], [2.0, 1.0] ] @=> scales["just"]; float et[13][2]; for(0 => int i; i <= 12; ++i){ 1.0 => et[i][0]; Math.pow(2.0, i / 12.0) => et[i][1]; } et @=> scales["equalTempered"]; <<< scales["just"][0] >>>;

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Bay Area Computer Music Technology Group
by Noah Thorp 19 Nov '08

19 Nov '08

Thank you to Pyramind for hosting the Bay Area Computer Music Technlogy Group this month. Our speakers will be Yale Professor Paul Hudak on Haskore (a functional programming audio library written in Haskell) and Smule CTO and Stanford Assistant Professor Ge Wang on iPhone audio applications (including Smule's #1 selling US iPhone app Ocarina). Hope to see some of you there. The details are below. Best, Noah Thorp Bay Area Computer Music Technology Group Organizer ------------------------------------------------- Bay Area Computer Music Technology Group (BArCMuT) Presentations Thursday, Nov 20th 2008 @ 7pm Pyramind, 832 Folsom, SF, CA Please RSVP here for event sign in: http://www.barcmut.org Haskore II: from Signals to Symphonies Paul Hudak Haskore is a computer music library written in Haskell. As such it is not a new language, although it has the "look and feel" of a special- purpose language. It is the only computer music programming environment based on a purely functional programming model. In the context of Yale's new Computing and the Arts initiative, Haskore is being re-designed and enhanced in a number of ways. In this talk we discuss the design rationale for Haskore II, describe its basic functionality, and highlight some of its more innovative features: a vertical language design (from signals to symphonies), a separation between structure and interpretation (form and function), its graphical music interface (GMI), real-time sound synthesis, and its use of functional reactive programming (FRP) in interactive music applications. Introducing Smule: Interactive Sonic Media on the iPhone Ge Wang We present our adventure (so far) with Smule, a startup company exploring interactive sonic media on the iPhone (whatever that might mean). Co-founded in 2008 by CEO Jeff Smith, CTO Ge Wang, along with several Stanford and Princeton professors and students, Smule serves as a unique platform for research and development combining the state- of-the-art in computer music research with the potential to bring its visions to a wide population. In this presentation, we not only showcase the end products (Sonic Lighter, Sonic Boom, Sonic Vox, and the #1 bestselling Ocarina), but also discuss the roles sound and interaction take on in creating them. Smule is exploring how to change the way people think, work, and play through sound and music. Smule/Ocarina: http://www.smule.com/ http://ocarina.smule.com/ Also, after the BArCMuT presentations Peter Nyboer will be debuting his new video and hand drawing sound interface at the Luggage Store Music by The Eyeful event. In his words: "My newest creation combines the joys of music improv, mathematics lecturing, simple concepts of sound synthesis, and mid-(last)-century notions of electronic music scores. My instrument is a pen-and-paper, channeled through a computer." Peter will perform a little after 9pm here: http://www.luggagestoregallery.org , 1007 Market St. (@ 6th St), SF, CA. BIOS --- PAUL HUDAK was one of the principal organizers of the "Haskell Committee," an international group of computer scientists who designed Haskell. He is co-Editor-in-Chief for the Journal of Functional Programming, Editor for the Journal of Higher-Order and Symbolic Logic, and charter member of IFIP Working Group 2.8 on Functional Programming. He is a recipient of an NSF Presidential Young Investigator Award and an IBM Faculty Development Award, and in 2004 was elected as a Fellow of the ACM. Prof. Hudak was also Chairman of the Department of Computer Science at Yale from 1999 to 2005. Paul is also the author of The Haskell School of Expression: Learning Functional Programming through Multimedia, Cambridge University Press, New York, 2000. For more information about Paul and projects he is involved in visit these links: http://cs-www.cs.yale.edu/homes/hudak-paul/ http://www.cs.yale.edu/people/hudak.html GE WANG is currently an assistant professor at Stanford University in the Center for Computer Research in Music and Acoustics (CCRMA). His research interests include interactive software systems (of all sizes) for computer music, programming languages, sound synthesis and analysis, music information retrieval, new performance ensembles (e.g., laptop orchestra) and paradigms (e.g., live coding), visualization, interfaces for human-computer interaction, interactive audio over networks, and methodologies for education at the intersection of computer science and music. Ge is the chief architect and co-creator of the ChucK audio programming language, and the Audicle environment. He was a founding developer and co-director of the Princeton Laptop Orchestra (PLOrk), the founder and director of the Stanford Laptop Orchestra (SLOrk). Ge composes and performs via various electro-acoustic and computer- mediated means. Additionally, Ge is the Co-founder and CTO of Smule (a.k.a. SonicMule, Inc.), a startup company exploring interactive sonic media for the iPhone. Smule serves as a unique platform for research and development combining the state-of-the-art in computer music research with the potential to bring its visions to a wide population. Ge is the lead designer of Smule's Ocarina (currently the paid #1 iPhone application in the U.S. as well as in 20 other stores around the world). Ge Wang: http://ccrma.stanford.edu/~ge/

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Re: [chuck-users] negative duration syntax and bug
by Les Hall 16 Nov '08

16 Nov '08

Hi Lucas, I am sorry if my little joke backfired and you misinterpreted it as being in poor taste. Kassen knows my sense of humor so he got it, and he joked right back at me. Any language with sporks and upChucKs can't be taken too seriously, lol! Cheers and don't do anything I wouldn't do (twice)! Les (Inventor) p.s. remember: "Time flies like an arrow, fruit flies like a banana."

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LiSa SndBuf rate bug?
by mike clemow 15 Nov '08

15 Nov '08

Hey folks, In the below example (which you will all find in the LiSa-SndBuf.ck file in examples in your installation), after populating the buffer in the LiSa object with the values of the samples from SndBuf, the rate of the LiSa object is set equal to 2. in order to play back normally. Why is it not 1? Why this should be the case makes little sense to me and I respectfully submit this as a bug, unless someone can provide a reasonable explanation. Thoughts? -Mike ----- //ugens SndBuf buf; LiSa lisa => dac; //change this path to your own sample "/Users/dan/Files/Chuck/LiSa_examples/TomVega.wav" => buf.read; //set lisa buffer size to sample size buf.samples() * 1::samp => lisa.duration; //transfer values from SndBuf to LiSa for ( 0 => int i; i < buf.samples(); i++ ) { //args are sample value and sample index (dur must be integral in samples) lisa.valueAt(buf.valueAt(i), i::samp); } //party on... 1 => lisa.play; 2. => lisa.rate; //look at some of the data //returns value at given time, with linear interpolation <<< Std.rand2f( 0., lisa.duration() / 1::samp ) :: samp => lisa.valueAt >>>; //hang on until it's done... lisa.duration() * 0.5 => now; -- http://michaelclemow.com http://semiotech.org

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Re: [chuck-users] negative duration syntax and bug
by Les Hall 14 Nov '08

14 Nov '08

Press Release: In a startling discovery made earlier today by musician and self-described ChucKist "Kassen", it was revealed that negative time actually exists. Long theorized by science fiction authors and audiences, the discovery has baffled modern scientists. When questioned, the mysterious "Kassen" was unavailable for comment because he had travelled back in time to enjoy last weekend's party one more time. It is, however, suggested by other ChucKists that the time reversal phenomenon exists only in the mind of ChucK and is in fact a bug. Presumably a bug that flies backward, but that, again, is pure speculation. In fact, the whole concept of negative time in a ChucKian universe may actually be a very carefully planned practical joke created by the ChucK Dev team in the future of the past which is actually now. This has been an up-to-the-minute report (so to speak). Les (Inventor)

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negative duration syntax and bug
by Kassen 12 Nov '08

12 Nov '08

Fellow ChucKists, This is runs; <<<-1 * second>>>; Hence we know that negative durations are fine. This, on the other hand causes a problem; <<<-1::second>>>; We can get around that by using this; <<<(-1)::second>>>; That one does run but it also seems very clumsy to me. I'm getting the impression that for durations expressed like -3::second the minus sign somehow isn't a part of the number while elsewhere it is. This doesn't strike me as very coherent. While I was testing some other things around negative durations I noticed that this will crash with seg-fault; second -=> now; Admittedly it would be a type of expression that would only be useful with negative durations... Probably quite rare but it shouldn't crash the whole VM like that. Yours, Kas.

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array declaration bug
by eduard aylon 11 Nov '08

11 Nov '08

Hello list, I found out that declaring arrays in this way: float a[], b[]; is buggy, as it seems the type for b[] is not taken as float. Maybe something else happens here (maybe passing by ref), I haven't check thoroughly (don't know if it happens with other types as well). See the following code: // ******************************* // this works: // ******************************* float freq, amp; fun void Do( float freq, float amp) { <<<"do sthg">>>; } Do(freq,amp); // ******************************* // also works: arrays declared in separate lines // ******************************* float freq1[1]; float amp1[1]; fun void Do( float freq[], float amp[]) { <<<"do sthg">>>; } Do(freq1,amp1); // ******************************* // throws error :argument type(s) do not match // arrays declared in the same line // ******************************* float freq2[1], amp2[1]; Do(freq2,amp2);

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dangerous games with shreds
by eduard aylon 11 Nov '08

11 Nov '08

Sorry list for bombing you with so many questions, but got this funny one, which I thought would be interesting to post. The patch below loops endlessly although no while(true) loop exists in the "main". If you try the patch, be warn that your computer may (or may not) become unresponsive. The code makes sense, and the behaviour as well, but should chuck throw a warning when something like this happens? I came up with this, while trying to have a process for reading and another for writing, but didn't want to advance time in any of them. eduard class mySpork { Event write; Event read; fun void start(){ read.signal(); <<<"started">>>; } fun void Write() { // NOTE: time is not advanced in this function while(true) { write => now; //<<< "writing" >>>; read.signal(); } } fun void Read() { // NOTE: time is not advanced in this function while(true) { read => now; //<<< "reading" >>>; write.signal(); } } } mySpork myspork; spork~myspork.Read(); spork~myspork.Write(); me.yield(); myspork.start(); <<< "loops forever">>>; 1::second => now; <<< "and never gets here">>>;

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