CATAN(3P)

💖 CATAN — complex arc tangent functions 💖

okay bestie, listen up, we're doing catan today and honestly? it's giving trigonometry but make it imaginary ✨. This page lives in the POSIX Programmer's Manual (section 3P, our beloved), so let's get into it 🫶

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🌸 PROLOG 🌸

so before we even start, a lil heads-up no cap:

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. 💀

like... it might not even exist on ur machine. vibe check first, bestie.

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✨ NAME ✨

catan, catanf, catanl — complex arc tangent functions

three icons, one job. the trio we deserved. 👑

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🎀 SYNOPSIS 🎀

#include <complex.h>

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

okay so you pick ur precision: catan for double complex, catanf for float complex, catanl for long double complex. all of them take a z and hand u back the arc tangent. slay 💅

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🦋 DESCRIPTION 🦋

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 — like, if they beef, that was NOT on purpose, we promise. This volume of POSIX.1‐2017 defers to the ISO C standard, periodt.

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

branch cuts outside [-i, +i] on the imaginary axis. remember that. it's the whole plot twist of this function fr fr. 🔥

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🌈 RETURN VALUE 🌈

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.

so: imaginary axis = go wild, no limits, main character energy 🌈. real axis = stuck between -π/2 and +π/2. that's the assignment. ✨

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💜 ERRORS 💜

No errors are defined.

like... none. zero. she doesn't miss. 💅

The following sections are informative. (iykyk — informative means it's just vibes and context, not requirements 🫶)

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🍓 EXAMPLES 🍓

None.

not me giving u zero examples 😭. the manpage said no and honestly? respect the boundaries.

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🧚 APPLICATION USAGE 🧚

None.

nothing to add bestie, she's self-explanatory 💖

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⭐ RATIONALE ⭐

None.

no reasoning given, no reasoning needed. iconic behaviour honestly.

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🔥 FUTURE DIRECTIONS 🔥

None.

the future is bright and also unspecified ✨

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👑 SEE ALSO 👑

• ctan() — the inverse-ish bestie, go say hi
• The Base Definitions volume of POSIX.1‐2017, <complex.h> — where the header lives

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💖 COPYRIGHT 💖

okay this part is the ✨legal girlie✨ section, we don't rewrite this one, we just hold it gently:

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 .

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and that's the whole page bestie, we ate and left no crumbs 💅✨

this lil number came to u from IEEE/The Open Group, dated 2017, and it's the CATAN(3P) page from the POSIX Programmer's Manual. mwah, go compute some arc tangents 🦋💖🎀