Flute acoustics: measurement, modelling and design - School of ...

330 APPENDIX B. PROGRAM LISTINGS
if (sizeVector(w->cells) == 0)
lastBore = w->head->downstreamBore;
else {
lastCell = (UnitCell)elementAt(w->cells,
sizeVector(w->cells) - 1);
lastBore = lastCell->bore;
}
s = (BoreSegment)elementAt(lastBore, sizeVector(lastBore) - 1);
return radiationZ(f, s->c, s->rho, s->radius2, w->flange);
}
complex woodwindDownstreamZ(double f, Woodwind w) {
TransferMatrix m;
UnitCell cell;
int cellCount;
m = boreMatrix(f, w->head->downstreamBore,
boreLength(w->head->downstreamBore));
for (cellCount = 0; cellCount < sizeVector(w->cells); cellCount++) {
cell = (UnitCell)elementAt(w->cells, cellCount);
rmultm(m, unitCellMatrix(f, cell, boreLength(cell->bore)));
}
return calcZin(m, woodwindLoadZ(f, w));
}
TransferMatrix traverseHoleMatrix(double f, Hole hole) {
TransferMatrix m = identitym();
complex Z_hole, Z_i, Z_a;
/* calculate the input impedance to the hole */
Z_hole = holeInputImpedance(f, hole);
/* calculate the inner radiation impedance */
Z_i = holeInnerRadiationImpedance(f, hole);
/* calculate the series impedance */
Z_a = holeSeriesImpedance(f, hole);
/* assign the impedances to the correct matrix element */
m->C = divz(one, addz(Z_i, Z_hole));
m->B = Z_a;
}
return m;
complex holeInputImpedance(double f, Hole hole) {
TransferMatrix holeMatrix;
double t;
double a = hole->boreRadius;
double b = hole->radius;
complex Z_L;
/* calculate the length t (inluding the matching length
correction) */
t = hole->length + matchingLengthCorrection(a, b);
/* calculate the matrix (with losses) for the tube section