Calculate the hyperbolic tangent
#include <math.h> double tanh( double x ); float tanhf( float x ); long double tanhl( long double x );
These functions compute the hyperbolic tangent of x radians.
When the x argument is large, partial or total loss of significance may occur.
To check for error situations, use feclearexcept() and fetestexcept(). For example:
The hyperbolic tangent value.
If x is: | These functions return: | Errors: |
---|---|---|
±0.0 | x | — |
±Inf | ±1.0 | — |
NaN | NaN | — |
Subnormal | x | — |
These functions raise FE_INEXACT if the FPU reports that the result can't be exactly represented as a floating-point number.
#include <stdio.h> #include <math.h> #include <fenv.h> #include <stdlib.h> int main( void ) { int except_flags; feclearexcept(FE_ALL_EXCEPT); printf( "%f\n", tanh(.5) ); except_flags = fetestexcept(FE_ALL_EXCEPT); if(except_flags) { /* An error occurred; handle it appropriately. */ } return EXIT_SUCCESS; }
produces the output:
0.462117
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | No |
Signal handler | No |
Thread | Yes |