[thirdparty/man-pages.git] / man3 / sincos.3

.\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
.\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
.\"     <mtk.manpages@gmail.com>
.\"
.\" %%%LICENSE_START(GPL_NOVERSION_ONELINE)
.\" Distributed under GPL
.\" %%%LICENSE_END
.\"
.TH SINCOS 3  2017-09-15 "GNU" "Linux Programmer's Manual"
.SH NAME
sincos, sincosf, sincosl \- calculate sin and cos simultaneously
.SH SYNOPSIS
.nf
.BR "#define _GNU_SOURCE" "         /* See feature_test_macros(7) */"
.B #include <math.h>
.PP
.BI "void sincos(double " x ", double *" sin ", double *" cos );
.BI "void sincosf(float " x ", float *" sin ", float *" cos );
.BI "void sincosl(long double " x ", long double *" sin ", long double *" cos );
.fi
.PP
Link with \fI\-lm\fP.
.SH DESCRIPTION
Several applications need sine and cosine of the same angle
.IR x .
These functions compute both at the same time, and store the results in
.I *sin
and
.IR *cos .
Using this function can be more efficient than two separate calls to
.BR sin (3)
and
.BR cos (3).
.PP
If
.I x
is a NaN,
a NaN is returned in
.I *sin
and
.IR *cos .
.PP
If
.I x
is positive infinity or negative infinity,
a domain error occurs, and
a NaN is returned in
.I *sin
and
.IR *cos .
.SH RETURN VALUE
These functions return
.IR void .
.SH ERRORS
See
.BR math_error (7)
for information on how to determine whether an error has occurred
when calling these functions.
.PP
The following errors can occur:
.TP
Domain error: \fIx\fP is an infinity
.I errno
is set to
.BR EDOM
(but see BUGS).
An invalid floating-point exception
.RB ( FE_INVALID )
is raised.
.SH VERSIONS
These functions first appeared in glibc in version 2.1.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lbw30 lb lb
l l l.
Interface	Attribute	Value
T{
.BR sincos (),
.BR sincosf (),
.BR sincosl ()
T}	Thread safety	MT-Safe
.TE
.SH CONFORMING TO
These functions are GNU extensions.
.SH NOTES
To see the performance advantage of
.BR sincos (),
it may be necessary to disable
.BR gcc (1)
built-in optimizations, using flags such as:
.PP
.in +4n
.EX
cc -O \-lm \-fno\-builtin prog.c
.EE
.in
.SH BUGS
Before version 2.22, the glibc implementation did not set
.\" https://www.sourceware.org/bugzilla/show_bug.cgi?id=15467
.I errno
to
.B EDOM
when a domain error occurred.
.SH SEE ALSO
.BR cos (3),
.BR sin (3),
.BR tan (3)
Commit	Line	Data
	1	.\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
	2	.\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
	3	.\" <mtk.manpages@gmail.com>
	4	.\"
	5	.\" %%%LICENSE_START(GPL_NOVERSION_ONELINE)
	6	.\" Distributed under GPL
	7	.\" %%%LICENSE_END
	8	.\"
	9	.TH SINCOS 3 2017-09-15 "GNU" "Linux Programmer's Manual"
	10	.SH NAME
	11	sincos, sincosf, sincosl \- calculate sin and cos simultaneously
	12	.SH SYNOPSIS
	13	.nf
	14	.BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */"
	15	.B #include <math.h>
	16	.PP
	17	.BI "void sincos(double " x ", double " sin ", double " cos );
	18	.BI "void sincosf(float " x ", float " sin ", float " cos );
	19	.BI "void sincosl(long double " x ", long double " sin ", long double " cos );
	20	.fi
	21	.PP
	22	Link with \fI\-lm\fP.
	23	.SH DESCRIPTION
	24	Several applications need sine and cosine of the same angle
	25	.IR x .
	26	These functions compute both at the same time, and store the results in
	27	.I *sin
	28	and
	29	.IR *cos .
	30	Using this function can be more efficient than two separate calls to
	31	.BR sin (3)
	32	and
	33	.BR cos (3).
	34	.PP
	35	If
	36	.I x
	37	is a NaN,
	38	a NaN is returned in
	39	.I *sin
	40	and
	41	.IR *cos .
	42	.PP
	43	If
	44	.I x
	45	is positive infinity or negative infinity,
	46	a domain error occurs, and
	47	a NaN is returned in
	48	.I *sin
	49	and
	50	.IR *cos .
	51	.SH RETURN VALUE
	52	These functions return
	53	.IR void .
	54	.SH ERRORS
	55	See
	56	.BR math_error (7)
	57	for information on how to determine whether an error has occurred
	58	when calling these functions.
	59	.PP
	60	The following errors can occur:
	61	.TP
	62	Domain error: \fIx\fP is an infinity
	63	.I errno
	64	is set to
	65	.BR EDOM
	66	(but see BUGS).
	67	An invalid floating-point exception
	68	.RB ( FE_INVALID )
	69	is raised.
	70	.SH VERSIONS
	71	These functions first appeared in glibc in version 2.1.
	72	.SH ATTRIBUTES
	73	For an explanation of the terms used in this section, see
	74	.BR attributes (7).
	75	.TS
	76	allbox;
	77	lbw30 lb lb
	78	l l l.
	79	Interface Attribute Value
	80	T{
	81	.BR sincos (),
	82	.BR sincosf (),
	83	.BR sincosl ()
	84	T} Thread safety MT-Safe
	85	.TE
	86	.SH CONFORMING TO
	87	These functions are GNU extensions.
	88	.SH NOTES
	89	To see the performance advantage of
	90	.BR sincos (),
	91	it may be necessary to disable
	92	.BR gcc (1)
	93	built-in optimizations, using flags such as:
	94	.PP
	95	.in +4n
	96	.EX
	97	cc -O \-lm \-fno\-builtin prog.c
	98	.EE
	99	.in
	100	.SH BUGS
	101	Before version 2.22, the glibc implementation did not set
	102	.\" https://www.sourceware.org/bugzilla/show_bug.cgi?id=15467
	103	.I errno
	104	to
	105	.B EDOM
	106	when a domain error occurred.
	107	.SH SEE ALSO
	108	.BR cos (3),
	109	.BR sin (3),
	110	.BR tan (3)