; docformat = 'rst'
;+
; Inverse hyperbolic sine. Uses the formula:
;
; $$\text{asinh}(z) = \ln(z + \sqrt{1 + z^2})$$
;
; :Examples:
; The arc hyperbolic sine function looks like::
;
; IDL> x = 10. * findgen(1000) / 999. - 5.
; IDL> plot, x, mg_asinh(x), xstyle=1
;
; This should look like:
;
; .. image:: asinh.png
;
; :Returns:
; float, double, complex, or double complex depending on the input
;
; :Params:
; z : in, required, type=numeric
; input
;-
function mg_asinh, z
compile_opt strictarr
return, alog(z + sqrt(1 + z*z))
end