December 2009 - chuck-users - lists.cs.princeton.edu

Integer divisions
by Hans Aberg 15 Dec '09

15 Dec '09

I find the integer divisions C rule is problematic when working with intervals. Suppose I have [8/7, 7/6, 7/6, 8/7] and implement it as [Interval.r(8/7), Interval.r(7/6), Interval.r(7/6), Interval.r(8/7)] Then this is the same as: [Interval.r(0), Interval.r(0), Interval.r(0), Interval.r(0)] One has to add ".0" one of the numerator/denominator: [Interval.r(8.0/7), Interval.r(7.0/6), Interval.r(7.0/6), Interval.r(8.0/7)], One possible rule might be converting 32-bit int to 64-bit floats, and then only back to int when needed. The question if it then affects some ChucK legacy code. Hans

6 14

banshee
by David Loberg Code 15 Dec '09

15 Dec '09

Any suggestions on how to create a scraped string effect in ChucK? (like in Henry Cowell's Banshee) http://upload.wikimedia.org/wikipedia/en/f/f0/Cowell-The_Banshee.ogg thanks david David Loberg Code School of Music Western Michigan University Kalamazoo, MI 49008 code(a)wmich.edu

2 1

mini shortcuts mistery
by Kassen 14 Dec '09

14 Dec '09

Fellow ChucKists, dear Spencer. For me the mini on Linux, using the Gnome desktop, has lately been acting up. Shortcuts like ctrl-c, ctrl-v, ctrl-x stop working after a while, so do the ones for adding and replacing shreds. Strangely ctrl-d *does* work in this state. No other programs have shown this behaviour and it's not consistent; they disappear after a while and so far I haven't seen them return. I think only the latest version does this. I'd like to document under what conditions this happens but it's quite inconsistent. Yours, Kas.

1 0

pitch tracking in ChucK
by Robert Poor 12 Dec '09

12 Dec '09

I need a low-latency pitch tracker for real-time performance work -- has anyone implemented one in ChucK? I'm ready to write one if need be -- it would be fun to start playing with the UAna objects -- but I don't feel the need to replicate work already done. Thanks in advance. - Rob

4 8

Mixed Object Lists and Hierarchy
by mike clemow 12 Dec '09

12 Dec '09

Hi list, Why can't I make an array of a parent type with objects of a single type, which is a child of the parent? class Foo { int foo; } class Bar extends Foo { int bar; } class Spam extends Foo { int spam; } Bar bara, barb, barc; Spam spama, spamb, spamc; Foo fooa, foob, fooc; [ bara, barb, barc ] @=> Bar bars[]; // okay [ bara, spamb, fooc ] @=> Foo foos[]; // mixed children okay [ bara, barb, barc ] @=> Foo morefoos[]; // incompatible types for assignment? best, Mike -- http://michaelclemow.com http://semiotech.org

3 5

Cloning
by Hans Aberg 11 Dec '09

11 Dec '09

ChucK does not have cloning for reference object, right? That is, the semantic equivalent of an this explicit copy-constructor pseudocode: class A {...} A a0; ... new A(a0) @=> A a1; That is, instead of merely setting a1 to the same reference as that of a0, create a new independent copy, and set its references to that of a0 (shallow copy). It is a problem in the program I wrote, scale.ck: if modifying tuning data, one actually manipulates the data of the original tuning loaded into memory. This is cool, but if I want to be able to reload the original data, I will have to write my own cloning operator. The difference is illustrated in the code below. First I make a shallow copy of a to b, which means that I can change b without changing a. Then I set a reference of a to b, after which changing b also changes a. Hans ---- clone.ck ---- class A { string s; } A a; "a" @=> a.s; A b; "b" @=> b.s; chout <= "a.s = " <= a.s <= ", b.s = " <= b.s <= ".\n"; "c" @=> b.s; chout <= "\"c\" @=> b.s; a = " <= a.s <= ", b = " <= b.s <= ".\n"; a.s @=> b.s; chout <= "a.s @=> b.s; a.s = " <= a.s <= ", b.s = " <= b.s <= ".\n"; "d" @=> b.s; chout <= "\"d\" @=> b.s; a.s = " <= a.s <= ", b.s = " <= b.s <= ".\n"; a @=> b; chout <= "a @=> b; a.s = " <= a.s <= ", b.s = " <= b.s <= ".\n"; "e" @=> b.s; chout <= "\"e\" @=> b.s; a.s = " <= a.s <= ", b.s = " <= b.s <= ".\n"; ---- run ---- $ chuck clone.ck a.s = a, b.s = b. "c" @=> b.s; a = a, b = c. a.s @=> b.s; a.s = a, b.s = a. "d" @=> b.s; a.s = a, b.s = d. a @=> b; a.s = a, b.s = a. "e" @=> b.s; a.s = e, b.s = e. --------

3 4

eChucK Update
by Les Hall 10 Dec '09

10 Dec '09

Hey fellow ChucKists, In the last eChucK update I made a joking reference to ChucK and eChucK going out on a date together because I was interfacing the first working eChucK prototype to ChucK. Dropping the silly personification here, I am happy to report that the experiment was a success. I added code to an existing Boolean Sequencer program so that it sent control signals to the eChucK board via the left and right channels of the headphones out jack. With a little bit of added circuitry, the eChucK board properly responded to the ChucK output signals. The result was nice enough that I injected vocals into the eChucK board and controlled the buttons and sliders to create guitar and percussion sounds with interesting musical qualities. I then did a couple of one-hour internet radio shows (called "Inventor's Inventions) on the electro-music station. These two shows are available for listening in the electro-music radio archives which reside in the "Streaming Radio Station" sub-forum of www.electro-music.com (nearby where the ChucK forum is). The very latest news is that the board house (E-TekNet) has manufactured the first run of eChucK Karplus Strong circuit boards and UPS is scheduled to deliver them to my door tomorrow. Nine of the ten boards are spoken for and I expect to sell the last remaining one sometime soon. Some of the boards are sold bare, and some are to be assembled by myself for the customers at a reasonable cost. The bare boards sold for $21 + shipping ($5 US, $10 International) each. Also in the works is the companion circuit board, a Boolean Sequencing board which creates complex musical sequences from a simple logic matrix of 6x8 DIP switches. The designs are such that the BS board attaches to the top of the KS board with standoffs, forming a battery-powered eChucK "brick" suitable for use by a performing artist or studio artist. In addition to the stand-alone brick-style operation, both boards are designed to be used in a modular synthesizer either separately or in conjunction. Overall, the response from the community has been quite positive. One modular synthesizer customer said that it would require three to five modules to do the job of a single KS board, so if you want to do guitar or percussion sounds via Karplus Strong on a modular synthesizer the value is significant. Some people have voiced interest in eventually (as the design evolves) purchasing four or more KS boards or BS+KS board pairs so that they can create songs with multiple voices (ie: 2 guitars and 2 drum types). Another person would like to create guitar chords by using a few KS boards, one for each string of a chord. So anyway, that's the update. Progress continues and it's a really fun thing for me to be doing, so I'll keep at it. Your comments, suggestions, and questions are welcome as always. Les

1 0

miniAudicle Installation Error
by Les Hall 10 Dec '09

10 Dec '09

Hi folks, I just tried to install miniAudicle 0.2.0 (gidora) on my eMac and got the following error: The following disk images failed to mount miniAudicle-0.2.0a.dmg no mountable file systems I'm running OSX 10.3.9, which is kind of old. I cannot upgrade my OSX because the SuperDrive failed (for the second time), and besides I'm not to keen on paying Apple "rent" to use my eMac. I say "rent" because their OSX upgrades cost $129 and come out every 18 months or so, resulting in a "rental" payment to Apple of $7 per month. This is unacceptable to me so I cannot and will not upgrade my OSX. Is this decision also locking me out of miniAudicle upgrades? Thanks for your reply. Les

1 0

Problem with mixed float int lists
by Hans Aberg 10 Dec '09

10 Dec '09

ChucK does not admit explicit lists with numbers bot having and not having the decimal point, as in the example below. The problem is really that I made a program that writes tuning data to a file, which then should be pasted back into a .ck file. If the float value has not fractional part, 'chuck' writes it without decimal point. For example, it writes 440 Hz not 440.0 Hz. The first idea would be have 'chuck' always writing floats with a decimal point. But if the tuning data comes from some other source, it may not have a decimal point. One then ends up editing this data by hand, which is cumbersome. So I think 'chuck' should be able to convert explicit mixed float-int lists to float[]. There might also be some floats formatting capabilities. Hans ---- float_int_list.ck ---- [0.0, 1.0] @=> float as[]; // OK. [0, 1.0] @=> float bs[]; // array init [...] contains incompatible types... fun void f(float xs[]) {} f([0.0, 1.2]); // OK. f([0, 1.0]); // array init [...] contains incompatible types... f([0, 1]); // argument type(s) do not match: --------

2 7

initialization of static variables
by Robert Poor 09 Dec '09

09 Dec '09

Gang: I now understand a bit more about initialization of static variables -- more accurately, about execution of top-level code -- and while it's not earth-shattering, I thought I'd pass it along. It may avoid some astonishment. The rules are simple, but are different than I thought: -- top level forms INSIDE a class definition are executed every time an instance of that class is created. -- top level forms OUTSIDE of a class definition are executed once when the file loads. To see the implication on initializing a static variable, consider the following: ===== file: t1.ck public class Statix { // UNO is set with to new value at every call to 'new Statix' static Object @ UNO; (new Object) @=> UNO; // DUE is set once after the first call to 'new Statix' static Object @ DUE; if (DUE == null) (new Object) @=> DUE; // TRE is set once when the file is loaded (see below) static Object @ TRE; <<< "at a: UNO=", Statix.UNO, "DUE=", Statix.DUE, "TRE=", Statix.TRE >>>; } <<< "at b: UNO=", Statix.UNO, "DUE=", Statix.DUE, "TRE=", Statix.TRE >>>; (new Statix) @=> Statix.TRE; <<< "at c: UNO=", Statix.UNO, "DUE=", Statix.DUE, "TRE=", Statix.TRE >>>; ===== file: t2.ck <<< "at d: UNO=", Statix.UNO, "DUE=", Statix.DUE, "TRE=", Statix.TRE >>>; new Statix @=> Statix @ _t1; <<< "at e: UNO=", Statix.UNO, "DUE=", Statix.DUE, "TRE=", Statix.TRE >>>; new Statix @=> Statix @ _t2; <<< "at f: UNO=", Statix.UNO, "DUE=", Statix.DUE, "TRE=", Statix.TRE >>>; ===== the output: % chuck t1.ck t2.ck at b: UNO= 0x0 DUE= 0x0 TRE= 0x0 at a: UNO= 0x5e5aa0 DUE= 0x5e5af0 TRE= 0x0 at c: UNO= 0x5e5aa0 DUE= 0x5e5af0 TRE= 0x5e6670 at d: UNO= 0x5e5aa0 DUE= 0x5e5af0 TRE= 0x5e6670 at a: UNO= 0x5e6ba0 DUE= 0x5e5af0 TRE= 0x5e6670 at e: UNO= 0x5e6ba0 DUE= 0x5e5af0 TRE= 0x5e6670 at a: UNO= 0x5e6c00 DUE= 0x5e5af0 TRE= 0x5e6670 at f: UNO= 0x5e6c00 DUE= 0x5e5af0 TRE= 0x5e6670

2 3