sincos3
Calculate sin and cos simultaneously
Usage
#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);
Library
Math library (libm, -lm)
Overview
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.
Return value
These functions return void.
Errors
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.
Attributes
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
| sincos(), sincosf(), sincosl() | Thread safety | MT-Safe |
Notes
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
Releases
12 releases since Debian 3.1 (Sarge); the text changed 11 times.