On 06/13/2013 04:09 AM, eryksun wrote:
On Wed, Jun 12, 2013 at 6:31 PM, Dave Angel <da...@davea.name> wrote:
i = complex(0,1)
>>> 1j
1j
I had forgotten that notation for a complex literal. I knew the magic
syntax had j in it, but didn't remember it needs to be part of the
numeric token. Of course the output of the debugger should have
reminded me, but you did a better job.
http://en.wikipedia.org/wiki/Imaginary_unit#Alternative_notations
cmath.sqrt(float((math.e **(i * math.pi)).real))
The real/imag attributes are already floats:
>>> from math import e, pi, sin, cos
>>> cos(pi / 3), (e ** (1j * pi / 3)).real
(0.5000000000000001, 0.5000000000000001)
>>> sin(pi / 3), (e ** (1j * pi / 3)).imag
(0.8660254037844386, 0.8660254037844386)
Yeah, I know. I originally put the float in to get rid of the small bit
of imaginary noise that the complex exponentiation created. When that
failed, (apparently you can't use float() to get the real portion of a
complex value), I added the .real() and forgot to remove the float().
In case this wasn't obvious to everyone, I was just playing with the
"e to the I PI is minus one" trick, then feeding that -1 to square root.
--
DaveA
_______________________________________________
Tutor maillist - Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor
