sincos, sincosf, sincosl − calculate sin and cos simultaneously
Math library (libm, −lm)
#define
_GNU_SOURCE /* See feature_test_macros(7) */
#include <math.h>
void
sincos(double x, double *sin,
double *cos);
void sincosf(float x, float
*sin, float *cos);
void sincosl(long double x, long double
*sin, long double *cos);
Several applications need sine and cosine of the same angle x. These functions compute both at the same time, and store the results in *sin and *cos. Using this function can be more efficient than two separate calls to sin(3) and cos(3).
If x is a NaN, a NaN is returned in *sin and *cos.
If x is positive infinity or negative infinity, a domain error occurs, and a NaN is returned in *sin and *cos.
These functions return void.
See math_error(7) for information on how to determine whether an error has occurred when calling these functions.
The following
errors can occur:
Domain error: x is an infinity
errno is set to EDOM (but see BUGS). An invalid floating-point exception (FE_INVALID) is raised.
For an explanation of the terms used in this section, see attributes(7). |
GNU.
glibc 2.1.
To see the performance advantage of sincos(), it may be necessary to disable gcc(1) built-in optimizations, using flags such as:
cc −O −lm −fno−builtin prog.c
Before glibc 2.22, the glibc implementation did not set errno to EDOM when a domain error occurred.
cos(3), sin(3), tan(3)