mkfilter/complex.h

struct c_complex
{
    double re, im;
};

struct complex
{
    double re;
    double im;
    complex(double r, double i = 0.0) { re = r; im = i; }
    complex() { }                                       /* uninitialized complex */
    complex(c_complex z) { re = z.re; im = z.im; }      /* init from denotation */
};

extern complex csqrt(complex);
extern complex cexp(complex);
extern complex expj(double);        /* from complex.C */
extern complex evaluate(complex[], int, complex[], int, complex);   /* from complex.C */

inline double hypot(complex z) { return ::hypot(z.im, z.re); }
inline double atan2(complex z) { return ::atan2(z.im, z.re); }

inline complex cconj(complex z)
{
    z.im = -z.im;
    return z;
}

inline complex operator * (double a, complex z)
{
    z.re *= a; z.im *= a;
    return z;
}

inline complex operator / (complex z, double a)
{
    z.re /= a; z.im /= a;
    return z;
}

inline void operator /= (complex &z, double a)
{
    z = z / a;
}

extern complex operator * (complex, complex);
extern complex operator / (complex, complex);

inline complex operator + (complex z1, complex z2)
{
    z1.re += z2.re;
    z1.im += z2.im;
    return z1;
}

inline complex operator - (complex z1, complex z2)
{
    z1.re -= z2.re;
    z1.im -= z2.im;
    return z1;
}

inline complex operator - (complex z)
{
    return 0.0 - z;
}

inline bool operator == (complex z1, complex z2)
{
    return (z1.re == z2.re)  &&  (z1.im == z2.im);
}

inline complex sqr(complex z)
{
    return z*z;
}