Re: [microsound] random numbers WAS:oval armani

[Derek Holzer <republikasleazka@xxxxxxxxxxx>]

brad,

----Original Message Follows----
From: { brad brace } <bbrace@xxxxxxxxxx>

I'm often wondering about the 'random-number' feature in
applications: how does one program _randomness? Is there
really such a thing?


if you want a technical answer, and not a rhetorical one:

"How does acomputer, which is designed to store and process numbers 
accurately and reproducably, obtain seemingly unpredictable random numbers? 
One way is to sample an external random process such as thermal noise, but 
this requires additional hardware. A less expensive and more commonly used 
approach is to employ an algorithm called a pseudo-random number generator 
which produces a sequence of numbers that satisfy most of the criteria for 
randomness, with the notable exception that the sequence repeats itself. It 
is possible to make the period of the sequence so long that for most 
purposes it can be considered random... pseudo random number generators 
generally use the most recently generated random number for calculating the 
next. As a result, most algorithms give the user the option of specifying a 
'seed' value...starting from the same 'seed' value will always yield the 
same sequence of random numbers. That means that two different computer 
runs...can always be made to have exactly the same results."

(Computer Music, Charles Dodge and Thomas A. Jerse, 1985)

kind of defeats the purpose, don't you think?

best,
derek


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