HP Fortran Programmer's Reference (September 2007)

Intrinsic procedures
Intrinsic procedure specifications
Chapter 11530
Result type/
type parameters
Same as X.
Result value
The result has a value equal to a processor-dependent approximation to arctan(X), expressed
in degrees, that lies in the range
-90 < ATAND(X) < 90.
Specific forms
DATAND,QATAND.
ATANH(X)
Description
Hyperbolic arctangent of radians.
Class
Elemental nonstandard function.
Argument
X must be of type real.
Result type/
type parameters
Same as X.
Result value
The result has a value equal to a processor-dependent approximation to the hyperbolic
arctangent of X.
Specific forms
DATANH, QATANH.