Common mathematical functions | |||||||||||||||||||||||||||||||
Mathematical special functions(C++17) | |||||||||||||||||||||||||||||||
Mathematical constants(C++20) | |||||||||||||||||||||||||||||||
Basic linear algebra algorithms(C++26) | |||||||||||||||||||||||||||||||
Data-parallel types (SIMD)(C++26) | |||||||||||||||||||||||||||||||
Floating-point environment(C++11) | |||||||||||||||||||||||||||||||
Complex numbers | |||||||||||||||||||||||||||||||
Numeric array (valarray ) | |||||||||||||||||||||||||||||||
Pseudo-random number generation | |||||||||||||||||||||||||||||||
Bit manipulation(C++20) | |||||||||||||||||||||||||||||||
Saturation arithmetic(C++26) | |||||||||||||||||||||||||||||||
Factor operations | |||||||||||||||||||||||||||||||
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Interpolations | |||||||||||||||||||||||||||||||
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Generic numeric operations | |||||||||||||||||||||||||||||||
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C-style checked integer arithmetic | |||||||||||||||||||||||||||||||
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Nearest integer floating point operations | |||||||||||||||||||||||||||||||||||||||||
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Floating point manipulation functions | |||||||||||||||||||||||||||||||||||||||||
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Classification and comparison | |||||||||||||||||||||||||||||||||||||||||
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Types | |||||||||||||||||||||||||||||||||||||||||
Macro constants | |||||||||||||||||||||||||||||||||||||||||
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Defined in header <cmath> | ||
(1) | ||
float cos(float num); double cos(double num); | (until C++23) | |
/*floating-point-type*/ cos(/*floating-point-type*/ num); | (since C++23) (constexpr since C++26) | |
float cosf(float num); | (2) | (since C++11) (constexpr since C++26) |
longdouble cosl(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 cos( Integer num); | (A) | (constexpr since C++26) |
std::cos
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::cos onv_num.
| (since C++26) |
A) Additional overloads are provided for all integer types, which are treated asdouble. | (since C++11) |
Contents |
num | - | floating-point or integer value representing angle in radians |
If no errors occur, the cosine ofnum (cos(num)) in the range[
-1.0,
+1.0]
, is returned.
The result may have little or no significance if the magnitude ofnum is large. | (until C++11) |
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.
Errors are reported as specified inmath_errhandling.
If the implementation supports IEEE floating-point arithmetic (IEC 60559),
The case where the argument is infinite is not specified to be a domain error in C, but it is defined as adomain error in POSIX.
The additional overloads are not required to be provided exactly as(A). They only need to be sufficient to ensure that for their argumentnum of integer type,std::cos(num) has the same effect asstd::cos(static_cast<double>(num)).
#include <cerrno>#include <cfenv>#include <cmath>#include <iomanip>#include <iostream>#include <numbers> // #pragma STDC FENV_ACCESS ON constexprdouble pi=std::numbers::pi;// or std::acos(-1) before C++20 constexprdouble your_cos(double x){double cos{1}, pow{x};for(auto fac{1ull}, n{1ull}; n!=19; fac*=++n, pow*= x)if((n&1)==0) cos+=(n&2?-pow: pow)/ fac;return cos;} int main(){std::cout<<std::setprecision(10)<<std::showpos<<"Typical usage:\n"<<"std::cos(pi/3) = "<< std::cos(pi/3)<<'\n'<<"your cos(pi/3) = "<< your_cos(pi/3)<<'\n'<<"std::cos(pi/2) = "<< std::cos(pi/2)<<'\n'<<"your cos(pi/2) = "<< your_cos(pi/2)<<'\n'<<"std::cos(-3*pi/4) = "<< std::cos(-3* pi/4)<<'\n'<<"your cos(-3*pi/4) = "<< your_cos(-3* pi/4)<<'\n'<<"Special values:\n"<<"std::cos(+0) = "<< std::cos(0.0)<<'\n'<<"std::cos(-0) = "<< std::cos(-0.0)<<'\n'; // error handlingstd::feclearexcept(FE_ALL_EXCEPT); std::cout<<"cos(INFINITY) = "<< std::cos(INFINITY)<<'\n';if(std::fetestexcept(FE_INVALID))std::cout<<" FE_INVALID raised\n";}
Possible output:
Typical usage:std::cos(pi/3) = +0.5your cos(pi/3) = +0.5std::cos(pi/2) = +6.123233996e-17your cos(pi/2) = -3.373452105e-15std::cos(-3*pi/4) = -0.7071067812your cos(-3*pi/4) = -0.7071067812Special values:std::cos(+0) = +1std::cos(-0) = +1cos(INFINITY) = -nan FE_INVALID raised
(C++11)(C++11) | computes sine (\({\small\sin{x}}\)sin(x)) (function)[edit] |
(C++11)(C++11) | computes tangent (\({\small\tan{x}}\)tan(x)) (function)[edit] |
(C++11)(C++11) | computes arc cosine (\({\small\arccos{x}}\)arccos(x)) (function)[edit] |
computes cosine of a complex number (\({\small\cos{z}}\)cos(z)) (function template)[edit] | |
applies the functionstd::cos to each element of valarray (function template)[edit] | |
C documentation forcos |