aboutsummaryrefslogtreecommitdiffstats
path: root/libm/man/atan2.3
diff options
context:
space:
mode:
authorElliott Hughes <enh@google.com>2013-01-30 19:06:37 -0800
committerElliott Hughes <enh@google.com>2013-02-01 14:51:19 -0800
commita0ee07829a9ba7e99ef68e8c12551301cc797f0f (patch)
treefefc432ee572779579a16d2868d4181a33399281 /libm/man/atan2.3
parenta990cf5b3392c5aef767aee1e67b4d7ef651afc6 (diff)
downloadandroid_bionic-a0ee07829a9ba7e99ef68e8c12551301cc797f0f.tar.gz
android_bionic-a0ee07829a9ba7e99ef68e8c12551301cc797f0f.tar.bz2
android_bionic-a0ee07829a9ba7e99ef68e8c12551301cc797f0f.zip
Upgrade libm.
This brings us up to date with FreeBSD HEAD, fixes various bugs, unifies the set of functions we support on ARM, MIPS, and x86, fixes "long double", adds ISO C99 support, and adds basic unit tests. It turns out that our "long double" functions have always been broken for non-normal numbers. This patch fixes that by not using the upstream implementations and just forwarding to the regular "double" implementation instead (since "long double" on Android is just "double" anyway, which is what BSD doesn't support). All the tests pass on ARM, MIPS, and x86, plus glibc on x86-64. Bug: 3169850 Bug: 8012787 Bug: https://code.google.com/p/android/issues/detail?id=6697 Change-Id: If0c343030959c24bfc50d4d21c9530052c581837
Diffstat (limited to 'libm/man/atan2.3')
-rw-r--r--libm/man/atan2.3187
1 files changed, 0 insertions, 187 deletions
diff --git a/libm/man/atan2.3 b/libm/man/atan2.3
deleted file mode 100644
index 421e17de0..000000000
--- a/libm/man/atan2.3
+++ /dev/null
@@ -1,187 +0,0 @@
-.\" Copyright (c) 1991 The Regents of the University of California.
-.\" All rights reserved.
-.\"
-.\" Redistribution and use in source and binary forms, with or without
-.\" modification, are permitted provided that the following conditions
-.\" are met:
-.\" 1. Redistributions of source code must retain the above copyright
-.\" notice, this list of conditions and the following disclaimer.
-.\" 2. Redistributions in binary form must reproduce the above copyright
-.\" notice, this list of conditions and the following disclaimer in the
-.\" documentation and/or other materials provided with the distribution.
-.\" 3. All advertising materials mentioning features or use of this software
-.\" must display the following acknowledgement:
-.\" This product includes software developed by the University of
-.\" California, Berkeley and its contributors.
-.\" 4. Neither the name of the University nor the names of its contributors
-.\" may be used to endorse or promote products derived from this software
-.\" without specific prior written permission.
-.\"
-.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
-.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
-.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-.\" SUCH DAMAGE.
-.\"
-.\" from: @(#)atan2.3 5.1 (Berkeley) 5/2/91
-.\" $FreeBSD: src/lib/msun/man/atan2.3,v 1.14 2005/01/28 21:13:34 ru Exp $
-.\"
-.Dd January 14, 2005
-.Dt ATAN2 3
-.Os
-.Sh NAME
-.Nm atan2 ,
-.Nm atan2f
-.Nd arc tangent functions of two variables
-.Sh LIBRARY
-.Lb libm
-.Sh SYNOPSIS
-.In math.h
-.Ft double
-.Fn atan2 "double y" "double x"
-.Ft float
-.Fn atan2f "float y" "float x"
-.Sh DESCRIPTION
-The
-.Fn atan2
-and the
-.Fn atan2f
-functions compute the principal value of the arc tangent of
-.Fa y/ Ns Ar x ,
-using the signs of both arguments to determine the quadrant of
-the return value.
-.Sh RETURN VALUES
-The
-.Fn atan2
-and the
-.Fn atan2f
-functions, if successful,
-return the arc tangent of
-.Fa y/ Ns Ar x
-in the range
-.Bk -words
-.Bq \&- Ns \*(Pi , \&+ Ns \*(Pi
-.Ek
-radians.
-Here are some of the special cases:
-.Bl -column atan_(y,x)_:=____ sign(y)_(Pi_atan2(Xy_xX))___
-.It Fn atan2 y x No := Ta
-.Fn atan y/x Ta
-if
-.Ar x
-> 0,
-.It Ta sign( Ns Ar y Ns )*(\*(Pi -
-.Fn atan "\\*(Bay/x\\*(Ba" ) Ta
-if
-.Ar x
-< 0,
-.It Ta
-.No 0 Ta
-if x = y = 0, or
-.It Ta
-.Pf sign( Ar y Ns )*\\*(Pi/2 Ta
-if
-.Ar x
-= 0 \(!=
-.Ar y .
-.El
-.Sh NOTES
-The function
-.Fn atan2
-defines "if x > 0,"
-.Fn atan2 0 0
-= 0 despite that previously
-.Fn atan2 0 0
-may have generated an error message.
-The reasons for assigning a value to
-.Fn atan2 0 0
-are these:
-.Bl -enum -offset indent
-.It
-Programs that test arguments to avoid computing
-.Fn atan2 0 0
-must be indifferent to its value.
-Programs that require it to be invalid are vulnerable
-to diverse reactions to that invalidity on diverse computer systems.
-.It
-The
-.Fn atan2
-function is used mostly to convert from rectangular (x,y)
-to polar
-.if n\
-(r,theta)
-.if t\
-(r,\(*h)
-coordinates that must satisfy x =
-.if n\
-r\(**cos theta
-.if t\
-r\(**cos\(*h
-and y =
-.if n\
-r\(**sin theta.
-.if t\
-r\(**sin\(*h.
-These equations are satisfied when (x=0,y=0)
-is mapped to
-.if n \
-(r=0,theta=0).
-.if t \
-(r=0,\(*h=0).
-In general, conversions to polar coordinates
-should be computed thus:
-.Bd -unfilled -offset indent
-.if n \{\
-r := hypot(x,y); ... := sqrt(x\(**x+y\(**y)
-theta := atan2(y,x).
-.\}
-.if t \{\
-r := hypot(x,y); ... := \(sr(x\u\s82\s10\d+y\u\s82\s10\d)
-\(*h := atan2(y,x).
-.\}
-.Ed
-.It
-The foregoing formulas need not be altered to cope in a
-reasonable way with signed zeros and infinities
-on a machine that conforms to
-.Tn IEEE 754 ;
-the versions of
-.Xr hypot 3
-and
-.Fn atan2
-provided for
-such a machine are designed to handle all cases.
-That is why
-.Fn atan2 \(+-0 \-0
-= \(+-\*(Pi
-for instance.
-In general the formulas above are equivalent to these:
-.Bd -unfilled -offset indent
-.if n \
-r := sqrt(x\(**x+y\(**y); if r = 0 then x := copysign(1,x);
-.if t \
-r := \(sr(x\(**x+y\(**y);\0\0if r = 0 then x := copysign(1,x);
-.Ed
-.El
-.Sh SEE ALSO
-.Xr acos 3 ,
-.Xr asin 3 ,
-.Xr atan 3 ,
-.Xr cos 3 ,
-.Xr cosh 3 ,
-.Xr math 3 ,
-.Xr sin 3 ,
-.Xr sinh 3 ,
-.Xr tan 3 ,
-.Xr tanh 3
-.Sh STANDARDS
-The
-.Fn atan2
-function conforms to
-.St -isoC .