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cargf, carg, cargl

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< c‎ | numeric‎ | complex
Revision as of 15:53, 9 February 2014 by P12 (Talk | contribs)

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Defined in header <complex.h>
float       cargf( float complex z );
(since C99)
double      carg( double complex z );
(since C99)
long double cargl( long double complex z );
(since C99)

Computes the argument (also called phase angle) of z, with a branch cut along the negative real axis.

[edit] Parameters

z - complex argument

[edit] Return value

The argument of z in the interval (−π; π).

[edit] Example

#include <stdio.h>
#include <complex.h>
#include <math.h>
 
int main() 
{
    double complex z;                 /* complex number     */
    double phase;                     /* phase angle        */
    double rtod = 180.0/acos(-1.0);   /* radians to degrees */
 
    z = 0.0+0.0*_Complex_I;
    phase = carg(z);
    printf("%9f radians,  %6.1f degrees\n", phase,phase*rtod);
 
    z = 1.0+1.0*_Complex_I;
    phase = carg(z);
    printf("%9f radians,  %6.1f degrees\n", phase,phase*rtod);
 
    z = -1.0+1.0*_Complex_I;
    phase = carg(z);
    printf("%9f radians,  %6.1f degrees\n", phase,phase*rtod);
 
    z = -1.0-1.0*_Complex_I;
    phase = carg(z);
    printf("%9f radians,  %6.1f degrees\n", phase,phase*rtod);
 
    z = 1.0-1.0*_Complex_I;
    phase = carg(z);
    printf("%9f radians,  %6.1f degrees\n", phase,phase*rtod);
 
    return 0;
}

Output:

0.000000 radians,     0.0 degrees
 0.785398 radians,    45.0 degrees
 2.356194 radians,   135.0 degrees
-2.356194 radians,  -135.0 degrees
-0.785398 radians,   -45.0 degrees