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Re: complex arithmetic [message #1918]

Wed, 06 April 1994 08:37

isaacman
Messages: 20
Registered: June 1992

Junior Member

In article <thompson.765642193@serts.gsfc.nasa.gov>, thompson@serts.gsfc.nasa.gov (William Thompson) writes...
> I think the problem is that such problems are degenerate--there is more than
> one correct answer. For example, if we define A and B to be
>
> IDL> A = COMPLEX(1,1)
> IDL> B = COMPLEX(-1,-1)
>
> and C to be
>
> and B to be
>
> IDL> C = A^2
> IDL> PRINT, C
> ( 0.00000, 2.00000)
>
> then A can be thought of as the square root of C. However, so can B, because
> A^2 and B^2 resolve to the same value. Thus, which is the correct answer for
> C^(0.5)?
>
> Evidently, IDL gets around this ambiguity by not allowing one to calculate a
> complex number to a non-integer power, even if the floating point number could
> be simplified to an integer such as in your example above.

I don't agree with this at all. IDL has no problem taking the square
root of positive real numbers, even though (-2.)^2 = (2.)^2

Rich Isaacman

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[Message index]

		Re: complex arithmetic By: isaacman on Wed, 06 April 1994 08:37
		Re: complex arithmetic By: salchegg on Wed, 06 April 1994 07:36
		Re: complex arithmetic By: thompson on Wed, 06 April 1994 07:23
		Re: complex arithmetic By: jjp on Wed, 06 April 1994 06:23
		Re: complex arithmetic By: landers on Wed, 06 April 1994 06:17
		Re: complex arithmetic By: stl on Tue, 05 April 1994 23:49

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