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Diffstat (limited to 'modules++/DSPIcomplex.h')
| -rw-r--r-- | modules++/DSPIcomplex.h | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/modules++/DSPIcomplex.h b/modules++/DSPIcomplex.h new file mode 100644 index 0000000..ad3e041 --- /dev/null +++ b/modules++/DSPIcomplex.h @@ -0,0 +1,191 @@ +/* + * DSPIcomplex.h - Quick and dirty inline class for complex numbers + * (mainly to compute filter poles/zeros, not to be used inside loops) + * Copyright (c) 2000 by Tom Schouten + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#ifndef DSPIcomplex_h +#define DSPIcomplex_h + +#include <math.h> +#include <iostream> + +class DSPIcomplex +{ + public: + inline DSPIcomplex() {_r = _i = 0;} + inline DSPIcomplex(const float &a, const float &b) {setCart(a, b);} + inline DSPIcomplex(const float &phasor) {setAngle(phasor);} + + inline void setAngle(const float &angle) {_r = cos(angle); _i = sin(angle);} + inline void setPolar(const float &phasor, const float &norm) + {_r = norm * cos(phasor); _i = norm * sin(phasor);} + inline void setCart(const float &a, const float &b) {_r = a; _i = b;} + + inline const float& r() const {return _r;} + inline const float& i() const {return _i;} + + inline float norm2() const {return _r*_r+_i*_i;} + inline float norm() const {return sqrt(norm2());} + inline void normalize() {float n = 1.0f / norm(); _r *= n; _i *= n;} + + inline DSPIcomplex conj() const {return DSPIcomplex(_r, -_i);} + + inline float angle() const {return atan2(_i, _r);} + + + inline DSPIcomplex operator+ (const DSPIcomplex &a) const + { + return DSPIcomplex(_r + a.r(), _i + a.i()); + } + inline DSPIcomplex operator+ (float f) const + { + return DSPIcomplex(_r + f, _i); + } + inline DSPIcomplex operator- (const DSPIcomplex &a) const + { + return DSPIcomplex(_r - a.r(), _i - a.i()); + } + inline DSPIcomplex operator- (float f) const + { + return DSPIcomplex(_r - f, _i); + } + + inline DSPIcomplex operator* (const DSPIcomplex &a) const + { + return DSPIcomplex(_r * a.r() - _i * a.i(), _i * a.r() + _r * a.i()); + } + inline DSPIcomplex operator* (float f) const + { + return DSPIcomplex(_r * f, _i * f); + } + inline DSPIcomplex operator/ (const DSPIcomplex &a) const + { + float n_t = 1.0f / a.norm2(); + return DSPIcomplex(n_t * (_r * a.r() + _i * a.i()), n_t * (_i * a.r() - _r * a.i())); + } + inline DSPIcomplex operator/ (float f) const + { + float n_t = 1.0f / f; + return DSPIcomplex(n_t * _r, n_t * _i); + } + + inline friend std::ostream& operator<< (std::ostream& o, DSPIcomplex& a) + { + return o << "(" << a.r() << "," << a.i() << ")"; + } + + inline friend DSPIcomplex operator+ (float f, DSPIcomplex& a) + { + return(DSPIcomplex(a.r() + f, a.i())); + } + + inline friend DSPIcomplex operator- (float f, DSPIcomplex& a) + { + return(DSPIcomplex(f - a.r(), - a.i())); + } + + inline friend DSPIcomplex operator/ (float f, DSPIcomplex& a) + { + return(DSPIcomplex(f,0) / a); + } + + // ???? + inline friend DSPIcomplex operator* (float f, DSPIcomplex& a) + { + return(DSPIcomplex(f*a.r(), f*a.i())); + } + + + inline DSPIcomplex& operator *= (float f) + { + _r *= f; + _i *= f; + return *this; + } + + inline DSPIcomplex& operator /= (float f) + { + _r /= f; + _i /= f; + return *this; + } + + inline DSPIcomplex& operator *= (DSPIcomplex& a) + { + float r_t = _r * a.r() - _i * a.i(); + _i = _r * a.i() + _i * a.r(); + _r = r_t; + + return *this; + } + + inline DSPIcomplex& operator /= (DSPIcomplex& a) + { + float n_t = a.norm2(); + float r_t = n_t * (_r * a.r() + _i * a.i()); + _i = n_t * (_i * a.r() - _r * a.i()); + _r = r_t; + + return *this; + } + + + float _r; + float _i; +}; + + +// COMPLEX LOG + +inline DSPIcomplex dspilog(DSPIcomplex a) /* complex log */ +{ + float r_t = log(a.norm()); + float i_t = a.angle(); + return DSPIcomplex(r_t, i_t); +} + +// COMPLEX EXP + +inline DSPIcomplex dspiexp(DSPIcomplex a) /* complex exp */ +{ + return (DSPIcomplex(a.i()) * exp(a.r())); +} + +// BILINEAR TRANSFORM analog -> digital + +inline DSPIcomplex bilin_stoz(DSPIcomplex a) +{ + DSPIcomplex a2 = a * 0.5f; + return((1.0f + a2)/(1.0f - a2)); +} + +// BILINEAR TRANSFORM digital -> analog + +inline DSPIcomplex bilin_ztos(DSPIcomplex a) +{ + return ((a - 1.0f) / (a + 1.0f))*2.0f; +} + +// not really a complex function but a nice complement to the bilinear routines + +inline float bilin_prewarp(float freq) +{ + return 2.0f * tan(M_PI * freq); +} + +#endif //DSPIcomplex_h |