std::asin, std::asinf, std::asinl
From cppreference.com
Defined in header <cmath> | ||
| (1) | ||
float asin (float num ); double asin (double num ); | (until C++23) | |
/*floating-point-type*/ asin (/*floating-point-type*/ num ); | (since C++23) (constexpr since C++26) | |
float asinf(float num ); | (2) | (since C++11) (constexpr since C++26) |
longdouble asinl(longdouble num ); | (3) | (since C++11) (constexpr since C++26) |
SIMD overload(since C++26) | ||
Defined in header <simd> | ||
template</*math-floating-point*/ V > constexpr/*deduced-simd-t*/<V> | (S) | (since C++26) |
Additional overloads(since C++11) | ||
Defined in header <cmath> | ||
template<class Integer > double asin ( Integer num ); | (A) | (constexpr since C++26) |
1-3) Computes the principal value of the arc sine of num. The library provides overloads of
std::asin for all cv-unqualified floating-point types as the type of the parameter.(since C++23)S) The SIMD overload performs an element-wise std::asin on v_num.
| (since C++26) |
A) Additional overloads are provided for all integer types, which are treated as double. | (since C++11) |
Contents |
[edit]Parameters
| num | - | floating-point or integer value |
[edit]Return value
If no errors occur, the arc sine of num (arcsin(num)) in the range [-| π |
| 2 |
| π |
| 2 |
If a domain error occurs, an implementation-defined value is returned (NaN where supported).
If a range error occurs due to underflow, the correct result (after rounding) is returned.
[edit]Error handling
Errors are reported as specified in math_errhandling.
Domain error occurs if num is outside the range [-1.0, 1.0].
If the implementation supports IEEE floating-point arithmetic (IEC 60559),
- If the argument is ±0, it is returned unmodified.
- If |num| > 1, a domain error occurs and NaN is returned.
- if the argument is NaN, NaN is returned.
[edit]Notes
The additional overloads are not required to be provided exactly as (A). They only need to be sufficient to ensure that for their argument num of integer type, std::asin(num) has the same effect as std::asin(static_cast<double>(num)).
[edit]Example
Run this code
#include <cerrno>#include <cfenv>#include <cmath>#include <cstring>#include <iostream> // #pragma STDC FENV_ACCESS ON int main(){std::cout<<"asin(1.0) = "<< asin(1)<<'\n'<<"2*asin(1.0) = "<<2* asin(1)<<'\n'<<"asin(-0.5) = "<< asin(-0.5)<<'\n'<<"6*asin(-0.5) ="<<6* asin(-0.5)<<'\n'; // special valuesstd::cout<<"asin(0.0) = "<< asin(0)<<" asin(-0.0)="<< asin(-0.0)<<'\n'; // error handlingerrno=0;std::feclearexcept(FE_ALL_EXCEPT); std::cout<<"asin(1.1) = "<< asin(1.1)<<'\n'; if(errno==EDOM)std::cout<<" errno == EDOM: "<<std::strerror(errno)<<'\n';if(std::fetestexcept(FE_INVALID))std::cout<<" FE_INVALID raised"<<'\n';}
Possible output:
asin(1.0) = 1.5708 2*asin(1.0) = 3.14159 asin(-0.5) = -0.523599 6*asin(-0.5) = -3.14159 asin(0.0) = 0 asin(-0.0)=-0 asin(1.1) = nan errno == EDOM: Numerical argument out of domain FE_INVALID raised
[edit]See also
(C++11)(C++11) | computes arc cosine (arccos(x)) (function) |
(C++11)(C++11) | computes arc tangent (arctan(x)) (function) |
(C++11)(C++11) | arc tangent, using signs to determine quadrants (function) |
(C++11)(C++11) | computes sine (sin(x)) (function) |
(C++11) | computes arc sine of a complex number (arcsin(z)) (function template) |
| applies the function std::asin to each element of valarray (function template) | |
C documentation for asin | |
