ATANH(X) (Fortran 2008)

Purpose

Inverse hyperbolic tangent function.

Class

Elemental function

Argument type and attributes

X
must be of type real or type complex.

Result type and attributes

Same as X.

Result value

The result value approximates the inverse hyperbolic tangent of X.

If X is of type complex, the imaginary part of the result value is as follows:
  • It is expressed in radians.
  • It is in the range -PI/2 ≤ AIMAG(ATANH(X)) ≤ PI/2.

Examples

ATANH(0.76159416) has the value 1.0, approximately.

ATANH((0.761594, 0.000000)) has the value (1.000000, 0.000000), approximately.