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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

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

#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

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

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