conjf, conj, conjl - cppreference.com (original) (raw)

Defined in header <complex.h>
float complex conjf( float complex z );	(1)	(since C99)
double complex conj( double complex z );	(2)	(since C99)
long double complex conjl( long double complex z );	(3)	(since C99)
Defined in header <tgmath.h>
#define conj( z )	(4)	(since C99)

1-3) Computes the complex conjugate of z by reversing the sign of the imaginary part.

Type-generic macro: if z has type long double complex, long double imaginary, or long double, conjl is called. If z has type float complex, float imaginary, or float, conjf is called. If z has type double complex, double imaginary, double, or any integer type, conj is called.

[edit] Parameters

[edit] Return value

The complex conjugate of z.

[edit] Notes

On C99 implementations that do not implement I as _Imaginary_I, conj may be used to obtain complex numbers with negative zero imaginary part. In C11, the macro CMPLX is used for that purpose.

[edit] Example

#include <stdio.h> #include <complex.h> int main(void) { double complex z = 1.0 + 2.0I; double complex z2 = conj(z); printf("The conjugate of %.1f%+.1fi is %.1f%+.1fi\n", creal(z), cimag(z), creal(z2), cimag(z2)); printf("Their product is %.1f%+.1fi\n", creal(zz2), cimag(z*z2)); }

Output:

The conjugate of 1.0+2.0i is 1.0-2.0i Their product is 5.0+0.0i

[edit] References