crealf, creal, creall

 

C

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

 

Numerics

Common mathematical functions

Floating-point environment

Complex number arithmetics

Random number generation

Type-generic math

 

Complex number arithmetic

Types and the imaginary constant
complex _Complex_I CMPLX	imaginary _Imaginary_I I
Manipulation
cimag creal carg	cabs conj cproj
Power and exponential functions
cexp clog	cpow csqrt
Trigonometric functions
ccos csin ctan	cacos casin catan
Hyperbolic functions
ccosh csinh ctanh	cacosh casinh catanh

 

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)

See also

cimagcimagfcimagl (C99)(C99)(C99)	computes the imaginary part a complex number (function)
C++ documentation for real