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Re: what is i in idl 4.0 ? [message #16646 is a reply to message #16640]

Tue, 10 August 1999 00:00

Richard G. French
Messages: 65
Registered: June 1997

Member

John Stanly Videen wrote:
>
> Help,
>
> Does anyone know what the system variable representation for i is in idl
> 4.0?
>
> [ where i = sqrt(-1) ]
>
> In idl 3.6, it used to be !j, but this doesn't seem to work in 4.0....
>
> eg. this code works in 3.6, but not 4.0:
>
> phase=atan(imaginary(data_ref), float(data_ref))
> temp=exp(- phase * !j )
> data=temp*data
>
> john

I agree with David Fanning. Try putting this in your startup file:

DEFSYSV,'!j',dcomplex([0.d0,1.d0])

then, for example, you can do

IDL> print,exp(!J*!dpi/4)
( 0.70710678, 0.70710678)

DIck French

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[Message index]

		Re: what is i in idl 4.0 ? By: gurman on Tue, 10 August 1999 00:00
		Re: what is i in idl 4.0 ? By: Richard G. French on Tue, 10 August 1999 00:00
		Re: what is i in idl 4.0 ? By: davidf on Mon, 09 August 1999 00:00

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