Random Number Generator

DragonGuy · Apr 2nd, 2002, 07:35 AM

Whats the best and fast way to generate a truely random numbers about say 250 million numbers to test my probability of an occurance happening? And I guess more specifically how good is EXCEL random number generator at producing truely random numbers? Thanks again for all the feedback I recieved from my last question.

Al Chara · Apr 2nd, 2002, 08:18 AM

Random numbers generated by a computer are not random. They are produced by an algorithm, which usually transforms a seed into a pseudo-random number, and another seed.

Excel's random number generator is:

sn+1 = (9821 sn + 211327) mod 1,000,000
xn+1 = sn+1/1,000,000

The best way to generate a random number is with a hardware random number generator. This is a piece of electronics that plugs into a computer and produces genuine random numbers as opposed to the pseudo-random numbers that are produced by a computer program. The usual method is to amplify noise generated by a resistor or a semi-conductor diode and feed this to a comparator or Schmitt trigger. If you sample the output you get a series of bits which are statistically independent. These can be assembled into bytes, integers or floating point numbers and then, into random numbers from other distributions.
_________________
Hope this helps.
Kind regards, Al.

[ This Message was edited by: Al Chara on 2002-04-02 07:29 ]

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Apr 2nd, 2002, 07:35 AM	#1
DragonGuy New Member Join Date: Mar 2002 Posts: 3	Whats the best and fast way to generate a truely random numbers about say 250 million numbers to test my probability of an occurance happening? And I guess more specifically how good is EXCEL random number generator at producing truely random numbers? Thanks again for all the feedback I recieved from my last question.

Apr 2nd, 2002, 08:18 AM	#2
Al Chara MrExcel MVP Join Date: Feb 2002 Location: Monterrey, Mexico Posts: 1,433	Random numbers generated by a computer are not random. They are produced by an algorithm, which usually transforms a seed into a pseudo-random number, and another seed. Excel's random number generator is: sn+1 = (9821 sn + 211327) mod 1,000,000 xn+1 = sn+1/1,000,000 The best way to generate a random number is with a hardware random number generator. This is a piece of electronics that plugs into a computer and produces genuine random numbers as opposed to the pseudo-random numbers that are produced by a computer program. The usual method is to amplify noise generated by a resistor or a semi-conductor diode and feed this to a comparator or Schmitt trigger. If you sample the output you get a series of bits which are statistically independent. These can be assembled into bytes, integers or floating point numbers and then, into random numbers from other distributions. _________________ Hope this helps. Kind regards, Al. [ This Message was edited by: Al Chara on 2002-04-02 07:29 ]