This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       None.

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for  Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical  and  Electronics
       Engineers, Inc and The Open Group.  In the event of any discrepancy between this version and the original
       IEEE  and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document.
       The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have  been  introduced
       during   the   conversion  of  the  source  files  to  man  page  format.  To  report  such  errors,  see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                                   2017                                         CATAN(3POSIX)

       The  functionality  described  on  this  reference  page is aligned with the ISO C standard. Any conflict
       between the requirements described  here  and  the  ISO C  standard  is  unintentional.  This  volume  of
       POSIX.1‐2017 defers to the ISO C standard.

       These  functions  shall  compute  the  complex  arc  tangent  of z, with branch cuts outside the interval
       [-i, +i] along the imaginary axis.

       No errors are defined.

       Thefollowingsectionsareinformative.

       None.

       None.

       catan, catanf, catanl — complex arc tangent functions

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of this interface
       may differ (consult the corresponding Linux manual page for details of Linux behavior), or the  interface
       may not be implemented on Linux.

       None.

       These functions shall return the complex arc tangent value,  in  the  range  of  a  strip  mathematically
       unbounded along the imaginary axis and in the interval [-π/2, +π/2] along the real axis.

ctan()

       The Base Definitions volume of POSIX.1‐2017, <complex.h>

       #include <complex.h>

       double complex catan(double complex z);
       float complex catanf(float complex z);
       long double complex catanl(long double complex z);