GEN44 — Generates a stiffness (connection) matrix for use in scanu/scanu2.
The file named in version 1 or the file stiff.num in the second case is read to create the matrix.
The first line of the file should be “ <MATRIX size=integer> ” and it creates a square matrix of the indicated size. This is followed by lines of two or three numbers, the first two denoting a connection from the first to the second. The third number is a weight; a weight of 2 is like having two links so more information gets distributed, while a zero weight means no link. If this third number is omitted it is taken as value 1. The list is terminated by a “ </MATRIX> ” line or end of file.
Example of this matrix format:
<MATRIX size=16>
1 2 2
2 3 1
3 4 3
4 5 1
5 6 4
6 7 1
7 8 5
8 9 6
9 10 7
10 11 6
11 12 5
12 13 4
13 14 3
14 15 2
15 16 1
16 1 9
14 13 2
10 3 6
6 4 2
2 14 7
</MATRIX>
can be given as zero in which case a size*size table is created. If the size in the gen statememt is too small for the matrix then space is re-allocated to the required size.
Note: to avoid confusion with other matrix formats, it is best to save this matrix format file using the extension file.matrxT.
Here is an example of the GEN44 generator. It uses the file gen44.csd.
Example 1326. Example of the GEN44 generator.
See the sections Real-time Audio and Command Line Flags for more information on using command line flags.
<CsoundSynthesizer> <CsOptions> ; Select audio/midi flags here according to platform -odac --limiter=0.95 ;;;realtime audio out & and limit loud sounds ;-iadc ;;;uncomment -iadc if realtime audio input is needed too ; For Non-realtime ouput leave only the line below: ; -o gen44.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> sr = 44100 ksmps = 32 nchnls = 1 0dbfs = 1 instr scan a0 init 0 irate = .01 kmass line 2,p3,5 kstiff line 30,p3,45 kcenter line .08,p3,.01 kdamp line .01,p3,.08 kpos line 0,p3,16 kdisplace line 0,p3,.5 ;scanu2 init,irate,ifndisplace,ifnmass,ifnmatrix,ifncentr,ifndamp,kmass,kmtrxstiff, ; kcentr, kdamp, ileft, iright, kpos, kdisplace, ain, idisp, id scanu2 -1, irate, 6, 2, 3, 4, 5, kmass, kstiff, kcenter, kdamp, .2, .7, kpos, kdisplace, a0, 1, 2 ;ar scans kamp, kfreq, ifntraj, id a1 scans ampdbfs(p4), cpspch(p5), 7, 2 a1 dcblock2 a1 out a1 endin </CsInstruments> <CsScore> ; Initial displacement condition f1 0 16 10 1 ; sine hammer f2 0 16 -7 1 16 1 ; Masses f3 0 0 -44 "string_with_extras-16.matrxT" ; Spring matrices f4 0 16 -7 1 16 1 ; Centering force, uniform initial centering f5 0 16 -7 1 16 1 ; Damping, uniform damping ; Initial displacement - (displacement, vel, and acceleration ; Acceleration is from stiffness matrix pos effect - increases acceleration f6 0 16 -7 .01 16 .01 ; uniform initial velocity-displacement f7 0 16 -5 .001 16 16 ; Trajectories i"scan" 0 2 -6 7.00 i"scan" 2 2 -6 5.00 i"scan" 4 2 -6 6.00 i"scan" 6 2 -6 8.00 i"scan" 8 2 -6 10.00 e </CsScore> </CsoundSynthesizer>
Here is another example of GEN44. It uses the file gen44-2.csd. The matrix file has 1024 masses.
Example 1327. Second example of the GEN44 generator.
<CsoundSynthesizer> <CsOptions> ; Select audio/midi flags here according to platform -odac --limiter=0.95 ;;;realtime audio out & and limit loud sounds ;-iadc ;;;uncomment -iadc if realtime audio input is needed too ; For Non-realtime ouput leave only the line below: ; -o gen44-2.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> sr = 44100 ksmps = 32 nchnls = 2 0dbfs = 1 ; by Menno Knevel 2024 instr 1 ; move the grain table initial ftgenonce 1, 0, 1024, 10, 1 ; initial position = sine wave idispl ftgenonce 2, 0, 1024, -7, .01, 1024, .01 ; displace imass ftgenonce 3, 0, 1024, -7, 5, 1024, 5 ; masses icent ftgenonce 4, 0, 1024, -7, .01, 1024, .1 ; centering idamp ftgenonce 5, 0, 1024, -7, -.1, 1024, -.21 ; damping itraj ftgenonce 6, 0, 1024, -7, 0, 1024, 1024 ; trajectory iw ftgenonce 7, 0, 1024, 20, 2 ; Hanning window for GEN20 a0 = 0 ; no audio injection kline line .07, p3, 0 ; simple envelope ;scanu2 init, irate, ifndisplace, ifnmass, imatrix, ifncentr, ifndamp, kmass, kmtrxstiff, kcentr, kdamp, ileft, iright, kpos, kdisplace, ain, idisp, id scanu2 1, .003, 2, 3, 100, 4, 5, 10, 6, 0.1, .9, .5, .1, 0, 0, a0, 0, -1 aL grain2 p4, p4, 2, 25, 1, 7 aR grain2 p4, p4, 2, 25, 1, 7 aL dcblock aL aR dcblock aR outs aL * kline, aR * kline endin </CsInstruments> <CsScore> f100 0 0 -44 "circularstring_1024.matrxT" ; text matrix, to be found in manual/examples i1 0 20 466.16376098248423 e </CsScore> </CsoundSynthesizer>
More information on the Scanned Synthesis opcodes: Working with Scanned Synthesis, written by Steven Yi, and some tutorials by Richard Boulanger.