sincos(3)

1sincos(3)                  Library Functions Manual                  sincos(3)
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NAME

6       sincos, sincosf, sincosl - calculate sin and cos simultaneously
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LIBRARY

9       Math library (libm, -lm)
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SYNOPSIS

12       #define _GNU_SOURCE         /* See feature_test_macros(7) */
13       #include <math.h>
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15       void sincos(double x, double *sin, double *cos);
16       void sincosf(float x, float *sin, float *cos);
17       void sincosl(long double x, long double *sin, long double *cos);
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DESCRIPTION

20       Several  applications  need sine and cosine of the same angle x.  These
21       functions compute both at the same time, and store the results in  *sin
22       and  *cos.  Using this function can be more efficient than two separate
23       calls to sin(3) and cos(3).
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25       If x is a NaN, a NaN is returned in *sin and *cos.
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27       If x is positive infinity or negative infinity, a domain error  occurs,
28       and a NaN is returned in *sin and *cos.
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RETURN VALUE

31       These functions return void.
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ERRORS

34       See  math_error(7) for information on how to determine whether an error
35       has occurred when calling these functions.
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37       The following errors can occur:
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39       Domain error: x is an infinity
40              errno is set to EDOM (but see BUGS).  An invalid  floating-point
41              exception (FE_INVALID) is raised.
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ATTRIBUTES

44       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
45       tributes(7).
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47       ┌────────────────────────────────────────────┬───────────────┬─────────┐
48       │Interface                                   │ Attribute     │ Value   │
49       ├────────────────────────────────────────────┼───────────────┼─────────┤
50       │sincos(), sincosf(), sincosl()              │ Thread safety │ MT-Safe │
51       └────────────────────────────────────────────┴───────────────┴─────────┘
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STANDARDS

54       GNU.
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HISTORY

57       glibc 2.1.
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NOTES

60       To see the performance advantage of sincos(), it may  be  necessary  to
61       disable gcc(1) built-in optimizations, using flags such as:
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63           cc -O -lm -fno-builtin prog.c
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BUGS

66       Before  glibc  2.22, the glibc implementation did not set errno to EDOM
67       when a domain error occurred.
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