04-05-2003, 11:20 AM
<digs notes out on random variables>
I cant find all my notes at the moment, but from memory random variables are generated from fairly simple algorithms using very large prime numbers. The main goals of a good random variable generator are to have a large cycle length and for each value to have statistical independance from the others (ie cant make predictions about the next number given the last few).
Of course no algorithmic generator can ever produce truely random numbers (because its based on a formula), but if the cycle length is long enough and statistical independance is achieved then it becomes difficult or impossible to tell that the sequence isnt random.
Thats not entirely true, it is accurate if you are refering to random numbers generated with computers which are usually formula based and use the timer to generate a seed value, however there have been studies done in using natural or real world phenomena to generate random numbers. I have seen work done with random numbers generated by using a digital camera and a lava-lamp, the pictures were assigned a unique number by combining the values of each pixel. The numbers generated will have a finite cycle length, but a lava-lamp doesn't obey any formula for its behaviour so theoritcally the numbers should be completely random. Other studies have done similar experiments with other objects as random number generators.
I cant find all my notes at the moment, but from memory random variables are generated from fairly simple algorithms using very large prime numbers. The main goals of a good random variable generator are to have a large cycle length and for each value to have statistical independance from the others (ie cant make predictions about the next number given the last few).
Of course no algorithmic generator can ever produce truely random numbers (because its based on a formula), but if the cycle length is long enough and statistical independance is achieved then it becomes difficult or impossible to tell that the sequence isnt random.
Quote:I'll skip over the fact that you can't ever generate truely random numbers
Thats not entirely true, it is accurate if you are refering to random numbers generated with computers which are usually formula based and use the timer to generate a seed value, however there have been studies done in using natural or real world phenomena to generate random numbers. I have seen work done with random numbers generated by using a digital camera and a lava-lamp, the pictures were assigned a unique number by combining the values of each pixel. The numbers generated will have a finite cycle length, but a lava-lamp doesn't obey any formula for its behaviour so theoritcally the numbers should be completely random. Other studies have done similar experiments with other objects as random number generators.
esus saves.... Passes to Moses, shoots, he scores!