sinpi, sinpif, sinpil, sinpid32, sinpid64, sinpid128
From cppreference.com
Defined in header <math.h>
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float sinpif( float arg ); |
(1) | (since C23) |
double sinpi( double arg ); |
(2) | (since C23) |
long double sinpil( long double 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>
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#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) |
Parameters
arg | - | floating-point value whose product with π represents an angle in radians
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Return value
If no errors occur, the sine of π·arg
(sin(π×arg)) in the range [-1, +1], is returned.
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.
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 family double sinpi(double arg) { return sin(arg * (double)3.1415926535897932384626433); } #endif int main(void) { const double pi = acos(-1); // typical usage printf("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 values printf("sinpi(+0) = %f\n", sinpi(0.0)); printf("sinpi(-0) = %f\n", sinpi(-0.0)); // error handling feclearexcept(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
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)
See also
(C99)(C99) |
computes sine (sin(x)) (function) |