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Re: RANDOMU bug (and HTML help) [message #14399 is a reply to message #14330]

Wed, 24 February 1999 00:00

steinhh
Messages: 260
Registered: June 1994

Senior Member

Bill Thompson wrote:

> Naively, I expected that
> if one deleted the seed variable, that would force IDL to re-initialize the
> seed, based on the system time or whatever. However, if my next command is
>
> IDL> delvar,seed & print,randomu(seed,3)
>
> I don't get any random numbers at all. To start getting random
> numbers again,
> I have to use a completely new variable name for the seed, e.g.
>
> IDL> print,randomu(seed2,3)
> 0.671149 0.383416 0.631635
>
> I don't know if this is properly speaking a bug or not, but it's certainly
> weird. As far as I can tell, this behavior is seen in all versions of IDL.

At first, I didn't understand what you were saying here - what could you
mean by "I don't get any random numbers at all"? Was it the same number
over and over again, or what? (In retrospect, I see that this is an
incorrect interpretation of the sentence..) Then I tried it myself:

IDL> delvar,seed & print,randomu(seed,3)

- and *no* output (hence "no random numbers at all")!

Seems like the guy who wrote the DELVAR command did something quite
bizarre:

IDL> delvar,seed & print,"HI"

- *still* no output!

Luckily, DELVAR cannot be used in programs!

Regards,

Stein Vidar

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[Message index]

		RANDOMU bug (and HTML help) By: landsman on Sun, 21 February 1999 00:00
		Re: RANDOMU bug (and HTML help) By: ajschmitt on Wed, 24 February 1999 00:00
		Re: RANDOMU bug By: Ivan Zimine on Wed, 24 February 1999 00:00
		Re: RANDOMU bug (and HTML help) By: steinhh on Wed, 24 February 1999 00:00
		Re: RANDOMU bug (and HTML help) By: thompson on Tue, 23 February 1999 00:00
		Re: RANDOMU bug (and HTML help) By: landsman on Tue, 23 February 1999 00:00
		Re: RANDOMU bug (and HTML help) By: landsman on Mon, 22 February 1999 00:00
		Re: RANDOMU bug (and HTML help) By: davidf on Mon, 22 February 1999 00:00
		Re: RANDOMU bug (and HTML help) By: ajschmitt on Mon, 22 February 1999 00:00
		Re: RANDOMU bug (and HTML help) By: mallors on Mon, 22 February 1999 00:00

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