std::tanh, std::tanhf, std::tanhl
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Defined in header
<cmath>
(1)
float tanh ( float num );
(until C++23)
double tanh ( double num );
/*floating-point-type*/
tanh ( /*floating-point-type*/ num );
(since C++23) tanh ( /*floating-point-type*/ num );
(constexpr since C++26)
float tanhf( float num );
(2)
(since C++11) (constexpr since C++26)
long double tanhl( long double num );
(3)
(since C++11) (constexpr since C++26)
SIMD overload (since C++26)
Defined in header
<simd>
template< /*math-floating-point*/ V >
(S)
(since C++26)
constexpr /*deduced-simd-t*/<V>
Additional overloads (since C++11)
Defined in header
<cmath>
template< class Integer >
double tanh ( Integer num );
(A)
(constexpr since C++26)
double tanh ( Integer num );
1-3) Computes the hyperbolic tangent of num. The library provides overloads of
std::tanh 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::tanh on v_num.- (See math-floating-point and deduced-simd-t for their definitions.)
A) Additional overloads are provided for all integer types, which are treated as double.
(since C++11)[edit] Parameters
num
-
floating-point or integer value
[edit] Return value
If no errors occur, the hyperbolic tangent of num (tanh(num), or enum
-e-num
-e-num
enum
+e-num
) is returned.
+e-num
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 .
If the implementation supports IEEE floating-point arithmetic (IEC 60559),
- if the argument is ±0, ±0 is returned.
- if the argument is ±∞, ±1 is returned.
- if the argument is NaN, NaN is returned.
[edit] Notes
POSIX specifies that in case of underflow, num is returned unmodified, and if that is not supported, and implementation-defined value no greater than DBL_MIN, FLT_MIN, and LDBL_MIN is returned.
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::tanh(num) has the same effect as std::tanh(static_cast<double>(num)).
[edit] Example
Run this code
#include <cmath> #include <iostream> #include <random> double get_random_between(double min, double max) { std::random_device rd; std::mt19937 gen(rd()); return std::uniform_real_distribution <>(min, max)(gen); } int main() { const double x = get_random_between(-1.0, 1.0); std::cout << std::showpos << "tanh(+1) = " << std::tanh(+1) << '\n' << "tanh(-1) = " << std::tanh(-1) << '\n' << "tanh(x)*sinh(2*x)-cosh(2*x) = " << std::tanh(x) * std::sinh (2 * x) - std::cosh (2 * x) << '\n' // special values: << "tanh(+0) = " << std::tanh(+0.0) << '\n' << "tanh(-0) = " << std::tanh(-0.0) << '\n'; }
Output:
tanh(+1) = +0.761594 tanh(-1) = -0.761594 tanh(x)*sinh(2*x)-cosh(2*x) = -1 tanh(+0) = +0 tanh(-0) = -0
[edit] See also
(C++11)(C++11)(C++11)
(function) [edit]
computes hyperbolic tangent of a complex number (\({\small\tanh{z}}\)tanh(z))
(function template) [edit]
(function template) [edit]
C documentation for tanh