8.23 ATANH — Inverse hyperbolic tangent function

Description:

ATANH(X) computes the inverse hyperbolic tangent of X.

Standard:

Fortran 2008 and later

Class:

Elemental function

Syntax:

RESULT = ATANH(X)

Arguments:

X	The type shall be REAL or COMPLEX.

Return value:

The return value has same type and kind as X. If X is complex, the imaginary part of the result is in radians and lies between -\pi/2 \leq \Im \atanh(x) \leq \pi/2.

Example:

          PROGRAM test_atanh
            REAL, DIMENSION(3) :: x = (/ -1.0, 0.0, 1.0 /)
            WRITE (*,*) ATANH(x)
          END PROGRAM

Specific names:

Name	Argument	Return type	Standard
DATANH(X)	REAL(8) X	REAL(8)	GNU extension

See also:

Inverse function: TANH