inverse hyperbolic cosh sinh and tanh

In working my way through the intrinsic Fortran functions it appears Plato does not support ACOSH, ASINH, or ATANH. Checking the list of Plato math functions I could not find these functions listed. Are there any iteration subroutines available?

These functions are included in the Fortran 2008 standard but have not yet been added to FTN95 (the compiler called by Plato). It would be a simple matter to provide your own function from the basic identities found here (https://en.wikipedia.org/wiki/Inverse_hyperbolic_functions).

DOUBLE PRECISION FUNCTION acosh(x)
DOUBLE PRECISION x
acosh = log(x + sqrt(x*x-1.0d0))
END FUNCTION acosh

PROGRAM test
DOUBLE PRECISION acosh
print*, acosh(2.0d0)
END

thanks

This might be of some use:-

http://www.davidgsimpson.com/software/invhyp_f90.txt

Ken

Thanks for the link. It's very useful. The single precision functions should probably be avoided even when the surrounding arithmetic is single precision.