crealf, creal, creall

Defined in header `<complex.h>`
float crealf( float complex z );	(1)	(since C99)
double creal( double complex z );	(2)	(since C99)
long double creall( long double complex z );	(3)	(since C99)
Defined in header `<tgmath.h>`
#define creal( z )	(4)	(since C99)

1-3) Returns the real part of z.

4) Type-generic macro: if z has type long double complex, long double imaginary, or long double, creall is called. If z has type float complex, float imaginary, or float, crealf is called. If z has type double complex, double imaginary, double, or any integer type, creal is called.

Parameters

z

-

complex argument

Return value

The real part of z.

This function is fully specified for all possible inputs and is not subject to any errors described in math_errhandling

Notes

For any complex variable z, z == creal(z) + I*cimag(z).

Example

Run this code

#include <stdio.h>
#include <complex.h>
 
int main(void)
{    
    double complex z = 1.0 + 2.0*I;
    printf("%f%+fi\n", creal(z), cimag(z));
}

Output:

1.000000+2.000000i

References

C11 standard (ISO/IEC 9899:2011):

7.3.9.6 The creal functions (p: 198-199)

7.25 Type-generic math <tgmath.h> (p: 373-375)

G.7 Type-generic math <tgmath.h> (p: 545)

C99 standard (ISO/IEC 9899:1999):

7.3.9.5 The creal functions (p: 180)

7.22 Type-generic math <tgmath.h> (p: 335-337)

G.7 Type-generic math <tgmath.h> (p: 480)

Language
headers
Type support
Dynamic memory management
Error handling
Program utilities
Variadic function support
Date and time utilities
Strings library
Algorithms
Numerics
Input/output support
Localization support
Thread support (C11)
Atomic operations (C11)
Technical Specifications

Common mathematical functions
Floating-point environment
Complex number arithmetics
Random number generation
Type-generic math