atanh(z)
returns the inverse hyperbolic tangent of z
CMath.atanh(1 + 1i) #=> (0.4023594781085251+1.0172219678978514i)
# File lib/cmath.rb, line 369 def atanh(z) begin if z.real? and z >= -1 and z <= 1 atanh!(z) else log((1.0 + z) / (1.0 - z)) / 2.0 end rescue NoMethodError handle_no_method_error end end