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Re: Re: Quick "Random[]" question

  • To: mathgroup at smc.vnet.net
  • Subject: [mg41906] Re: [mg41885] Re: Quick "Random[]" question
  • From: Bobby Treat <drmajorbob-MathGroup3528 at mailblocks.com>
  • Date: Mon, 9 Jun 2003 05:20:52 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

That's exactly what I meant by infinitesimal.  REALLY small.

Bobby

-----Original Message-----
From: Bill Rowe <listuser at earthlink.net>
To: mathgroup at smc.vnet.net
Subject: [mg41906] [mg41885] Re: Quick &quot;Random[]&quot; question

On 6/7/03 at 12:08 AM, drmajorbob-MathGroup3528 at mailblocks.com (Bobby 
Treat) wrote: &gt;We'll never know, as the probability of it is 
infinitesimal (zero &gt;theoretically, but in practice, infinitesimal). 
Actually, this may not be the case. The results of a call to Random 
with no arguments is a machine precision real. Since there is a finite 
number of machine precision numbers between any two other numbers, it 
follows the probability of anyone of them is 1/n where n = 2^(number of 
bits in the mantissa of a machine real) ~ 1/$MachineEpsilon (assuming 
well written code). The only issue I cannot address is whether the code 
specifically excludes 0.0 and 1.0 So; &gt;But plan for the possibility. 
That is, don't write code that breaks &gt;if it happens. is good advice 


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