The Open Group Base Specifications Issue 7, 2018 edition
IEEE Std 1003.1-2017 (Revision of IEEE Std 1003.1-2008)
Copyright © 2001-2018 IEEE and The Open Group

NAME

sin, sinf, sinl - sine function

SYNOPSIS

#include <math.h>

double sin(double
x);
float sinf(float
x);
long double sinl(long double
x);

DESCRIPTION

[CX] [Option Start] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2017 defers to the ISO C standard. [Option End]

These functions shall compute the sine of their argument x, measured in radians.

An application wishing to check for error situations should set errno to zero and call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if errno is non-zero or fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an error has occurred.

RETURN VALUE

Upon successful completion, these functions shall return the sine of x.

[MX] [Option Start] If x is NaN, a NaN shall be returned.

If x is ±0, x shall be returned.

If x is subnormal, a range error may occur
[Option End] [MXX] [Option Start] and x should be returned. [Option End]

[MX] [Option Start] If x is not returned, sin(), sinf(), and sinl() shall return an implementation-defined value no greater in magnitude than DBL_MIN, FLT_MIN, and LDBL_MIN, respectively.

If x is ±Inf, a domain error shall occur, and a NaN shall be returned. [Option End]

ERRORS

These functions shall fail if:

Domain Error
[MX] [Option Start] The x argument is ±Inf.

If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, then errno shall be set to [EDOM]. If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, then the invalid floating-point exception shall be raised. [Option End]

These functions may fail if:

Range Error
[MX] [Option Start] The value of x is subnormal

If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, then errno shall be set to [ERANGE]. If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, then the underflow floating-point exception shall be raised. [Option End]


The following sections are informative.

EXAMPLES

Taking the Sine of a 45-Degree Angle
#include <math.h>
...
double radians = 45.0 * M_PI / 180;
double result;
...
result = sin(radians);

APPLICATION USAGE

These functions may lose accuracy when their argument is near a multiple of or is far from 0.0.

On error, the expressions (math_errhandling & MATH_ERRNO) and (math_errhandling & MATH_ERREXCEPT) are independent of each other, but at least one of them must be non-zero.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

asin, feclearexcept, fetestexcept, isnan

XBD Treatment of Error Conditions for Mathematical Functions, <math.h>

CHANGE HISTORY

First released in Issue 1. Derived from Issue 1 of the SVID.

Issue 5

The last two paragraphs of the DESCRIPTION were included as APPLICATION USAGE notes in previous issues.

Issue 6

The sinf() and sinl() functions are added for alignment with the ISO/IEC 9899:1999 standard.

The DESCRIPTION, RETURN VALUE, ERRORS, and APPLICATION USAGE sections are revised to align with the ISO/IEC 9899:1999 standard.

IEC 60559:1989 standard floating-point extensions over the ISO/IEC 9899:1999 standard are marked.

Issue 7

POSIX.1-2008, Technical Corrigendum 1, XSH/TC1-2008/0585 [68] and XSH/TC1-2008/0586 [320] are applied.

End of informative text.

 

return to top of page

UNIX ® is a registered Trademark of The Open Group.
POSIX ® is a registered Trademark of The IEEE.
Copyright © 2001-2018 IEEE and The Open Group, All Rights Reserved
[ Main Index | XBD | XSH | XCU | XRAT ]