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11-15-2013
10:56 PM

11-15-2013
10:56 PM

handling of exp(-i*theta)

Hello,

I've gone between prime and 15 and settled on trying to implement some radial orthoganal moments in 15 due to better plotting and familiarity with keystrokes when editing equations. Here is the problem I am running into. Apologies up front...I'm at home and don't have Mathcad, or access to the files that are causing problems.

I'm working on a calculation that involves r * exp(-i*n*theta). Not having good results, and digging into the smaller parts, it appears that 15 has some issue with evaluation of exp(-i*theta).

If i set a range of theta like such:

nTheta = 300, theta = -pi, 2*pi/300 .. pi

R.out:= exp(-1i*theta)

R.out = returns values of the order 10^272. Has anyone seen anything similar to this. I believe exp(i*theta) should have magnitude 1 with a varying angle, so this makes no sense to me.

Thanks

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11-16-2013
04:40 AM

11-16-2013
04:40 AM

Re: handling of exp(-i*theta)

I am not experiencing any problems in the calculation of that expression.

You will have to describe more detailed what you did to prduce that result or wait until you have access to the file again and post it here.

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11-18-2013
12:42 PM

11-18-2013
12:42 PM

Re: handling of exp(-i*theta)

Your function, once you correct the range variable problem Werner describes, prioduces an imaginary answer. Try plotting the real (Re) and imaginary (Im) parts separaately