# cabsf, cabs, cabsl

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< c‎ | numeric‎ | complex

Defined in header `<complex.h>` |  |
float cabsf( float complex z ); | (1) | (since C99)
double cabs( double complex z ); | (2) | (since C99)
long double cabsl( long double complex z ); | (3) | (since C99)
Defined in header `<tgmath.h>` |  |
#define fabs( z ) | (4) | (since C99)

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

- C11 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)

- C99 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

carg cargf cargl (C99)(C99)(C99) | computes the phase angle of a complex number (function)
abs labs llabs (C99) | computes absolute value of an integral value (|x|) (function)
fabs fabsf fabsl (C99)(C99) | computes absolute value of a floating-point value (|x|) (function)
hypot hypotf hypotl (C99)(C99)(C99) | computes square root of the sum of the squares of two given numbers (√x2 +y2 ) (function)
C++ documentation for abs

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