cabsf, cabs, cabsl

 

C

Language

Headers

Type support

Program utilities

Variadic function support

Error handling

Dynamic memory management

Strings library

Algorithms

Numerics

Date and time utilities

Input/output support

Localization support

Concurrency support (哋它亢11)

Technical Specifications

Symbol index

 

Numerics

Common mathematical functions

Floating-point environment (哋它亢99)

Pseudo-random number generation

Complex number arithmetic (哋它亢99)

Type-generic math (哋它亢99)

 

Complex number arithmetic

Types and the imaginary constant
complex (哋它亢99) _Complex_I (哋它亢99)     CMPLX (哋它亢11)	imaginary (哋它亢99) _Imaginary_I (哋它亢99) I (哋它亢99)
Manipulation
cimag (哋它亢99) creal (哋它亢99) carg (哋它亢99)	cabs (哋它亢99) conj (哋它亢99) cproj (哋它亢99)
Power and exponential functions
cexp (哋它亢99) clog (哋它亢99)	cpow (哋它亢99) csqrt (哋它亢99)
Trigonometric functions
ccos (哋它亢99) csin (哋它亢99) ctan (哋它亢99)	cacos (哋它亢99) casin (哋它亢99) catan (哋它亢99)
Hyperbolic functions
ccosh (哋它亢99) csinh (哋它亢99) ctanh (哋它亢99)	cacosh (哋它亢99) casinh (哋它亢99) catanh (哋它亢99)

 

Defined in header <complex.h>
float       cabsf( float complex z );	(1)	(since 哋它亢99)
double      cabs( double complex z );	(2)	(since 哋它亢99)
long double cabsl( long double complex z );	(3)	(since 哋它亢99)
Defined in header <tgmath.h>
#define fabs( z )	(4)	(since 哋它亢99)

1-3) Computes the complex absolute value (also known as norm, modulus, or magnitude) of z.

4) Type-generic macro: if z has type long double complex or long double imaginary, cabsl is called. If z has type float complex or float imaginary, cabsf is called. If z has type double complex or double imaginary, cabs is called. For real and integer types, the corresponding version of fabs is called.

Parameters

z

-

complex argument

Return value

If no errors occur, returns the absolute value (norm, magnitude) of z.

Errors and special cases are handled as if the function is implemented as hypot(creal(z), cimag(z))

Example

Run this code

#include <stdio.h>
#include <complex.h>
 
int main(void)
{
    double complex z = 1.0 + 1.0*I;
    printf("%.1f%+.1fi cartesian is rho=%f theta=%f polar\n",
           creal(z), cimag(z), cabs(z), carg(z));
}

Output:

1.0+1.0i cartesian is rho=1.414214 theta=0.785398 polar

References

• 哋它亢11 standard (ISO/IEC 9899:2011):

• 7.3.8.1 The cabs functions (p: 195)

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

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

• 哋它亢99 standard (ISO/IEC 9899:1999):

• 7.3.8.1 The cabs functions (p: 177)

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

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

See also

cargcargfcargl (哋它亢99)(哋它亢99)(哋它亢99)	computes the phase angle of a complex number (function)
abslabsllabs (哋它亢99)	computes absolute value of an integral value (\(\small{|x|}\)|x|) (function)
fabsfabsffabsl (哋它亢99)(哋它亢99)	computes absolute value of a floating-point value (\(\small{|x|}\)|x|) (function)
hypothypotfhypotl (哋它亢99)(哋它亢99)(哋它亢99)	computes square root of the sum of the squares of two given numbers (\(\scriptsize{\sqrt{x^2+y^2} }\)√x2 +y2 ) (function)