sinpi, sinpif, sinpil, sinpid32, sinpid64, sinpid128
From cppreference.com
Defined in header <math.h> | ||
float sinpif(float arg ); | (1) | (since C23) |
double sinpi(double arg ); | (2) | (since C23) |
longdouble sinpil(longdouble arg ); | (3) | (since C23) |
_Decimal32 sinpid32( _Decimal32 arg ); | (4) | (since C23) |
_Decimal64 sinpid64( _Decimal64 arg ); | (5) | (since C23) |
_Decimal128 sinpid128( _Decimal128 arg ); | (6) | (since C23) |
Defined in header <tgmath.h> | ||
#define sinpi( arg ) | (7) | (since C23) |
1-6) Computes the sine of
π·arg measured in radians, thus regarding arg as a measurement in half-revolutions.7) Type-generic macro: calls the correct function based on the type of arg. If the argument has integer type, (2) is called.
The functions (4-6) are declared if and only if the implementation predefines | (since C23) |
Contents |
[edit]Parameters
| arg | - | floating-point value whose product with π represents an angle in radians |
[edit]Return value
If no errors occur, the sine of π·arg (sin(π×arg)) in the range [-1, +1], is returned.
[edit]Error handling
Errors are reported as specified in math_errhandling.
If the implementation supports IEEE floating-point arithmetic (IEC 60559):
- if the argument is ±0, it is returned unmodified;
- if the argument is ±∞, NaN is returned and FE_INVALID is raised;
- if the argument is NaN, NaN is returned.
[edit]Example
Run this code
#include <errno.h>#include <fenv.h>#include <math.h>#include <stdio.h> #ifndef __GNUC__#pragma STDC FENV_ACCESS ON#endif #if __STDC_VERSION__ < 202311L// A naive implementation of a subset of sinpi familydouble sinpi(double arg){returnsin(arg *(double)3.1415926535897932384626433);}#endif int main(void){constdouble pi =acos(-1); // typical usageprintf("sinpi(1) = %f, sin(pi) = %f\n", sinpi(1), sin(pi));printf("sinpi(0.5) = %f, sin(pi/2) = %f\n", sinpi(0.5), sin(pi /2));printf("sinpi(-0.75) = %f, sin(-3*pi/4) = %f\n", sinpi(-0.75), sin(-3* pi /4)); // special valuesprintf("sinpi(+0) = %f\n", sinpi(0.0));printf("sinpi(-0) = %f\n", sinpi(-0.0)); // error handlingfeclearexcept(FE_ALL_EXCEPT);printf("sinpi(INFINITY) = %f\n", sinpi(INFINITY));if(fetestexcept(FE_INVALID))puts(" FE_INVALID raised");}
Possible output:
sinpi(1) = 0.000000, sin(pi) = 0.000000 sinpi(0.5) = 1.000000, sin(pi/2) = 1.000000 sinpi(-0.75) = -0.707107, sin(-3*pi/4) = -0.707107 sinpi(+0) = 0.000000 sinpi(-0) = -0.000000 sinpi(INFINITY) = -nan FE_INVALID raised
[edit]References
- C23 standard (ISO/IEC 9899:2024):
- 7.12.4.13 The sinpi functions (p: 247-248)
- 7.27 Type generic math <tgmath.h> (p: 387)
[edit]See also
(C99)(C99) | computes sine (sin(x)) (function) |
