From 754bbf7a25a8dda49b5d08ef0d0443bbf5af0e36 Mon Sep 17 00:00:00 2001 From: Craig Jennings Date: Sun, 7 Apr 2024 13:41:34 -0500 Subject: new repository --- devdocs/c/numeric%2Fmath%2Fatanh.html | 84 +++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 devdocs/c/numeric%2Fmath%2Fatanh.html (limited to 'devdocs/c/numeric%2Fmath%2Fatanh.html') diff --git a/devdocs/c/numeric%2Fmath%2Fatanh.html b/devdocs/c/numeric%2Fmath%2Fatanh.html new file mode 100644 index 00000000..68ec0eb7 --- /dev/null +++ b/devdocs/c/numeric%2Fmath%2Fatanh.html @@ -0,0 +1,84 @@ +

atanh, atanhf, atanhl

Defined in header <math.h> 
float       atanhf( float arg );
+		 (1) (since C99) 
double      atanh( double arg );
+		 (2) (since C99) 
long double atanhl( long double arg );
+		 (3) (since C99)
Defined in header <tgmath.h> 
#define atanh( arg )
+		 (4) (since C99)
+1-3) Computes the inverse hyperbolic tangent of arg.
+4) Type-generic macro: If the argument has type long double, atanhl is called. Otherwise, if the argument has integer type or the type double, atanh is called. Otherwise, atanhf is called. If the argument is complex, then the macro invokes the corresponding complex function (catanhf, catanh, catanhl).

Parameters

+ +
arg - floating point value representing the area of a hyperbolic sector

Return value

If no errors occur, the inverse hyperbolic tangent of arg (tanh-1(arg), or artanh(arg)), is returned.

+

If a domain error occurs, an implementation-defined value is returned (NaN where supported).

+

If a pole error occurs, ±HUGE_VAL, ±HUGE_VALF, or ±HUGE_VALL is returned (with the correct sign).

+

If a range error occurs due to underflow, the correct result (after rounding) is returned.

+

Error handling

Errors are reported as specified in math_errhandling.

+

If the argument is not on the interval [-1, +1], a range error occurs.

+

If the argument is ±1, a pole error occurs.

+

If the implementation supports IEEE floating-point arithmetic (IEC 60559),

+

Notes

Although the C standard names this function "arc hyperbolic tangent", the inverse functions of the hyperbolic functions are the area functions. Their argument is the area of a hyperbolic sector, not an arc. The correct name is "inverse hyperbolic tangent" (used by POSIX) or "area hyperbolic tangent".

+

POSIX specifies that in case of underflow, arg is returned unmodified, and if that is not supported, an implementation-defined value no greater than DBL_MIN, FLT_MIN, and LDBL_MIN is returned.

+

Example

#include <stdio.h>
+#include <math.h>
+#include <float.h>
+#include <errno.h>
+#include <fenv.h>
+// #pragma STDC FENV_ACCESS ON
+ 
+int main(void)
+{
+    printf("atanh(0) = %f\natanh(-0) = %f\n", atanh(0), atanh(-0.0));
+    printf("atanh(0.9) = %f\n", atanh(0.9));
+    //error handling
+    errno = 0; feclearexcept(FE_ALL_EXCEPT);
+    printf("atanh(-1) = %f\n", atanh(-1));
+    if (errno == ERANGE)
+        perror("    errno == ERANGE");
+    if (fetestexcept(FE_DIVBYZERO))
+        puts("    FE_DIVBYZERO raised");
+}

Possible output:

+
atanh(0) = 0.000000
+atanh(-0) = -0.000000
+atanh(0.9) = 1.472219
+atanh(-1) = -inf
+    errno == ERANGE: Numerical result out of range
+    FE_DIVBYZERO raised

References

See also

+ + + + +
+
(C99)(C99)(C99)
 computes inverse hyperbolic sine (\({\small\operatorname{arsinh}{x} }\)arsinh(x))
(function)
+
(C99)(C99)(C99)
 computes inverse hyperbolic cosine (\({\small\operatorname{arcosh}{x} }\)arcosh(x))
(function)
+
(C99)(C99)
 computes hyperbolic tangent (\({\small\tanh{x} }\)tanh(x))
(function)
+
(C99)(C99)(C99)
 computes the complex arc hyperbolic tangent
(function)
C++ documentation for atanh
+ +
+Weisstein, Eric W. "Inverse Hyperbolic Tangent." From MathWorld — A Wolfram Web Resource.
+

+ © cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
+ https://en.cppreference.com/w/c/numeric/math/atanh +

+
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