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

250 APPENDIX B. PROGRAM LISTINGS
/*
Minima.h
By Andrew Botros, 2001-2004.
Modified by Paul Dickens, 2006-2007.
Listing B.13: Minima.h
Characterises the minima of acoustic impedance spectra.
IMPORTANT: Calculations are optimised for a spectrum resolution of
2Hz.
NOTE: The weighting of the frequency of an impedance extremum fit to
favour the absolute emtremum has been changed to an option in the
function 'parabolaExt' with a default of 0 (no weighting). A block
has also been added to the function 'extrema' to handle the case
when the next point to be considered is equal to the previous one
(this fixed a bug in the code).
*/
#ifndef MINIMA_H_PROTECTOR
#define MINIMA_H_PROTECTOR
#include "Vector.h"
#include "Note.h"
/* minmax: a minimum/maximum flag type */
typedef enum {MINIMUM, MAXIMUM} minmax;
/*
Minimum: {
musical note struct, frequency, impedance, bandwidth,
number of harmonics, weighted average harmonic impedance,
distance to left minimum in Hz,
difference in impedance of left minimum in dB,
distance to right minimum in Hz,
difference in impedance of right minimum in dB,
distance to left maximum in Hz,
difference in impedance of left maximum in dB,
distance to right maximum in Hz,
difference in impedance of right maximum in dB
}
*/
typedef struct minimum_str {
Note note;
double f;
double Z;
double B;
double numharm;
double meanharmZ;
double L_min_df;
double L_min_dZ;
double R_min_df;
double R_min_dZ;
double L_max_df;