# Fortran Wiki atanh

## 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 \\mathop{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