Re: minor bug in IDL 5 poisson random numbers?

[Craig Markwardt <craigmnet(at)astrog.physics.wisc.edu>]

Bruce Macintosh <bmac@igpp.llnl.gov> writes:
> 
> The statement
> 
> test=randomn(seed,10,poisson=50)
> 
> seems to generate a 
> % Program caused arithmetic error: Floating underflow
> 
> on my ultrasparc/solaris system about half the time. Presumably this
> is just some minor math thing - something in an exponential is
> getting very small - but it's faintly disconcerting and causes me to
> worry about the validity of the results. Does anyone have any
> comments?

I get this error message a lot running on the Alpha and Ultrasparc
platforms, when using the function MACHAR (which returns machine
precision constants, especially when doing MACHAR(/DOUBLE)).  So far
there are no problems, but I agree that this is an upsetting error
message to see, and can also hide other legitimate errors.

Craig

-- 
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Craig B. Markwardt, Ph.D.         EMAIL: craigmnet@astrog.physics.wisc.edu
Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response
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