man-pages/man3/hypot.3.html
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<H1>HYPOT</H1>
Section: Linux Programmer's Manual (3)<BR>Updated: 2017-09-15<BR><A HREF="#index">Index</A>
<A HREF="/cgi-bin/man/man2html">Return to Main Contents</A><HR>
<A NAME="lbAB">&nbsp;</A>
<H2>NAME</H2>
hypot, hypotf, hypotl - Euclidean distance function
<A NAME="lbAC">&nbsp;</A>
<H2>SYNOPSIS</H2>
<PRE>
<B>#include &lt;<A HREF="file:///usr/include/math.h">math.h</A>&gt;</B>
<B>double hypot(double </B><I>x</I><B>, double </B><I>y</I><B>);</B>
<B>float hypotf(float </B><I>x</I><B>, float </B><I>y</I><B>);</B>
<B>long double hypotl(long double </B><I>x</I><B>, long double </B><I>y</I><B>);</B>
</PRE>
<P>
Link with <I>-lm</I>.
<P>
Feature Test Macro Requirements for glibc (see
<B><A HREF="/cgi-bin/man/man2html?7+feature_test_macros">feature_test_macros</A></B>(7)):
<P>
<B>hypot</B>():
<DL COMPACT><DT id="1"><DD>
_ISOC99_SOURCE || _POSIX_C_SOURCE&nbsp;&gt;=&nbsp;200112L
<BR>&nbsp;&nbsp;&nbsp;&nbsp;||&nbsp;_XOPEN_SOURCE
<BR>&nbsp;&nbsp;&nbsp;&nbsp;||&nbsp;/*&nbsp;Since&nbsp;glibc&nbsp;2.19:&nbsp;*/&nbsp;_DEFAULT_SOURCE
<BR>&nbsp;&nbsp;&nbsp;&nbsp;||&nbsp;/*&nbsp;Glibc&nbsp;versions&nbsp;&lt;=&nbsp;2.19:&nbsp;*/&nbsp;_BSD_SOURCE&nbsp;||&nbsp;_SVID_SOURCE
</DL>
<BR>
<B>hypotf</B>(),
<B>hypotl</B>():
<DL COMPACT><DT id="2"><DD>
_ISOC99_SOURCE || _POSIX_C_SOURCE&nbsp;&gt;=&nbsp;200112L
<BR>&nbsp;&nbsp;&nbsp;&nbsp;||&nbsp;/*&nbsp;Since&nbsp;glibc&nbsp;2.19:&nbsp;*/&nbsp;_DEFAULT_SOURCE
<BR>&nbsp;&nbsp;&nbsp;&nbsp;||&nbsp;/*&nbsp;Glibc&nbsp;versions&nbsp;&lt;=&nbsp;2.19:&nbsp;*/&nbsp;_BSD_SOURCE&nbsp;||&nbsp;_SVID_SOURCE
</DL>
<A NAME="lbAD">&nbsp;</A>
<H2>DESCRIPTION</H2>
These functions return
sqrt(<I>x</I>*<I>x</I>+<I>y</I>*<I>y</I>).
This is the length of the hypotenuse of a right-angled triangle
with sides of length
<I>x</I>
and
<I>y</I>,
or the distance of the point
(<I>x</I>,<I>y</I>)
from the origin.
<P>
The calculation is performed without undue overflow or underflow
during the intermediate steps of the calculation.
<A NAME="lbAE">&nbsp;</A>
<H2>RETURN VALUE</H2>
On success, these functions return the length of a right-angled triangle
with sides of length
<I>x</I>
and
<I>y</I>.
<P>
If
<I>x</I>
or
<I>y</I>
is an infinity,
positive infinity is returned.
<P>
If
<I>x</I>
or
<I>y</I>
is a NaN,
and the other argument is not an infinity,
a NaN is returned.
<P>
If the result overflows,
a range error occurs,
and the functions return
<B>HUGE_VAL</B>,
<B>HUGE_VALF</B>,
or
<B>HUGE_VALL</B>,
respectively.
<P>
If both arguments are subnormal, and the result is subnormal,
a range error occurs,
and the correct result is returned.
<A NAME="lbAF">&nbsp;</A>
<H2>ERRORS</H2>
See
<B><A HREF="/cgi-bin/man/man2html?7+math_error">math_error</A></B>(7)
for information on how to determine whether an error has occurred
when calling these functions.
<P>
The following errors can occur:
<DL COMPACT>
<DT id="3">Range error: result overflow<DD>
<I>errno</I>
is set to
<B>ERANGE</B>.
An overflow floating-point exception
(<B>FE_OVERFLOW</B>)
is raised.
<DT id="4">Range error: result underflow<DD>
An underflow floating-point exception
(<B>FE_UNDERFLOW</B>)
is raised.
<DT id="5"><DD>
These functions do not set
<I>errno</I>
for this case.
</DL>
<A NAME="lbAG">&nbsp;</A>
<H2>ATTRIBUTES</H2>
For an explanation of the terms used in this section, see
<B><A HREF="/cgi-bin/man/man2html?7+attributes">attributes</A></B>(7).
<TABLE BORDER>
<TR VALIGN=top><TD><B>Interface</B></TD><TD><B>Attribute</B></TD><TD><B>Value</B><BR></TD></TR>
<TR VALIGN=top><TD>
<B>hypot</B>(),
<B>hypotf</B>(),
<B>hypotl</B>()
</TD><TD>Thread safety</TD><TD>MT-Safe<BR></TD></TR>
</TABLE>
<P>
<A NAME="lbAH">&nbsp;</A>
<H2>CONFORMING TO</H2>
C99, POSIX.1-2001, POSIX.1-2008.
<P>
The variant returning
<I>double</I>
also conforms to
SVr4, 4.3BSD.
<A NAME="lbAI">&nbsp;</A>
<H2>SEE ALSO</H2>
<B><A HREF="/cgi-bin/man/man2html?3+cabs">cabs</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?3+sqrt">sqrt</A></B>(3)
<A NAME="lbAJ">&nbsp;</A>
<H2>COLOPHON</H2>
This page is part of release 5.05 of the Linux
<I>man-pages</I>
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
<A HREF="https://www.kernel.org/doc/man-pages/.">https://www.kernel.org/doc/man-pages/.</A>
<P>
<HR>
<A NAME="index">&nbsp;</A><H2>Index</H2>
<DL>
<DT id="6"><A HREF="#lbAB">NAME</A><DD>
<DT id="7"><A HREF="#lbAC">SYNOPSIS</A><DD>
<DT id="8"><A HREF="#lbAD">DESCRIPTION</A><DD>
<DT id="9"><A HREF="#lbAE">RETURN VALUE</A><DD>
<DT id="10"><A HREF="#lbAF">ERRORS</A><DD>
<DT id="11"><A HREF="#lbAG">ATTRIBUTES</A><DD>
<DT id="12"><A HREF="#lbAH">CONFORMING TO</A><DD>
<DT id="13"><A HREF="#lbAI">SEE ALSO</A><DD>
<DT id="14"><A HREF="#lbAJ">COLOPHON</A><DD>
</DL>
<HR>
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