naginterfaces.library.specfun.arctanh¶
- naginterfaces.library.specfun.arctanh(x)[source]¶
arctanh
returns the value of the inverse hyperbolic tangent, .For full information please refer to the NAG Library document for s11aa
https://support.nag.com/numeric/nl/nagdoc_30.2/flhtml/s/s11aaf.html
- Parameters
- xfloat
The argument of the function.
- Returns
- athxfloat
The value of the inverse hyperbolic tangent, .
- Raises
- NagValueError
- (errno )
On entry, .
Constraint: .
The function has been called with an argument greater than or equal to in magnitude, for which is not defined.
- Notes
arctanh
calculates an approximate value for the inverse hyperbolic tangent of its argument, .For it is based on the Chebyshev expansion
where , , .
For , it uses
For , the function fails as is undefined.
- References
NIST Digital Library of Mathematical Functions