atanh(x): Inverse Hyperbolic Tangent

Inverse hyperbolic tangent function.

Declaration

Syntax

retval = atanh(x)
elemental real(p) function atanh(x)
elemental complex(p) function atanh(x)

Arguments

x the input value, can be real with value greater than or equal to 1 or of type complex.

Return values

The returned value has the kind of the input value and TYPE may be real or complex.

Описание

atanh(x) computes the inverse hyperbolic tangent function of x.

The result type and kind are the same as input value x.

If the result is complex, the imaginary part is expressed in radians and lies in the range

\(\frac{-\pi}{2} <= aimag (atanh(x)) <= \frac{\pi}{2}\)

If the result is real, it lies in the range

\(-1.0 < atanh(x) < 1.0\)

Types

Supported argument types float, double, complex float, complex double.

interface atanh
    module procedure satanh, datanh, catanh, zatanh
end interface

contains

interface
    elemental real(sp) function satanh(x)
    real(sp), intent(in) :: x
    end function

    elemental real(dp) function datanh(x)
    real(dp), intent(in) :: x
    end function

    elemental complex(sp) function catanh(x)
    complex(sp), intent(in) :: x
    end function

    elemental complex(dp) function zatanh(x)
    complex(dp), intent(in) :: x
    end function
end interface

Examples

program intrinsics_atanh
    implicit none
    print *, atanh(0.0)
end program

Result:

0.0

See Also

asinh, acosh.