Document hypotl().

Submitted by:	Steve Kargl <sgk@troutmask.apl.washington.edu>
This commit is contained in:
David Schultz 2008-03-30 20:03:29 +00:00
parent a641fc76eb
commit 01a13522ad
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=177759

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@ -28,14 +28,16 @@
.\" from: @(#)hypot.3 6.7 (Berkeley) 5/6/91
.\" $FreeBSD$
.\"
.Dd December 12, 2007
.Dd March 30, 2008
.Dt HYPOT 3
.Os
.Sh NAME
.Nm hypot ,
.Nm hypotf ,
.Nm hypotl ,
.Nm cabs ,
.Nm cabsf
.Nm cabsf ,
.Nm cabsl
.Nd Euclidean distance and complex absolute value functions
.Sh LIBRARY
.Lb libm
@ -45,25 +47,31 @@
.Fn hypot "double x" "double y"
.Ft float
.Fn hypotf "float x" "float y"
.Ft "long double"
.Fn hypotl "long double x" "long double y"
.In complex.h
.Ft double
.Fn cabs "double complex z"
.Ft float
.Fn cabsf "float complex z"
.Ft "long double"
.Fn cabsl "long double complex z"
.Sh DESCRIPTION
The
.Fn hypot
and
.Fn hypot ,
.Fn hypotf
and
.Fn hypotl
functions
compute the
sqrt(x*x+y*y)
in such a way that underflow will not happen, and overflow
occurs only if the final result deserves it.
The
.Fn cabs
and
.Fn cabs ,
.Fn cabsf
and
.Fn cabsl
functions compute the complex absolute value of
.Fa z .
.Pp
@ -82,11 +90,6 @@ Consequently
exactly;
in general, hypot and cabs return an integer whenever an
integer might be expected.
.Pp
The same cannot be said for the shorter and faster version of hypot
and cabs that is provided in the comments in cabs.c; its error can
exceed 1.2
.Em ulps .
.Sh NOTES
As might be expected,
.Fn hypot "v" "\*(Na"
@ -133,8 +136,10 @@ appeared in
The
.Fn hypot ,
.Fn hypotf ,
.Fn hypotl ,
.Fn cabs ,
.Fn cabsf ,
and
.Fn cabsf
.Fn cabsl
functions conform to
.St -isoC-99 .