[SciPy-dev] tanh(j*pi/2)

Robert Kern robert.kern@gmail....
Tue Jun 9 23:56:55 CDT 2009


On Tue, Jun 9, 2009 at 23:51, <d_l_goldsmith@yahoo.com> wrote:
>
>>>> import numpy as N
>>>> N.tanh(N.pi*1j/2)
> 16331778728383844j
>
> Is this the desired behavior?

It's what floating point arithmetic gives us. N.pi/2 is not precisely
the real number pi/2 so cos(N.pi/2) is not precisely 0 so
2/cos(N.pi/2) is not inf or nan.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless
enigma that is made terrible by our own mad attempt to interpret it as
though it had an underlying truth."
  -- Umberto Eco


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