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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

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

#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)