Don Schlesinger: Help: A weird problem

[Don Schlesinger]

> of your problem, try restarting your
> computer, and then run BJRM again.

Thanks, but nope. Three of the first 16 trials were more than 3.7-SD events!

Don

[Norm Wattenberger]

Correct. There was also a relevant bug in the Pentium 200Pro. But very few people bought the chip. The FDIV bug is not a problem in Visual Basic because it checks to see if the failure might occur and works around it. Also, although a linear-congruential generator is a modulo function, and by definition a modulo function is considered a divide function, no divide operation is actually performed. An AND and/or a SHIFT instruction are/is used instead as they are vastly faster and have the same (actually better) results given the divisor is a power of 2.

Regards,
norm

[John Auston]

Thanks to the info from Norm, regarding the Randomize function, I've changed the Random Walk code so that it now also works fine on computers as old as Don's! :-)

As Norm mentioned, if you over-call the Randomize function, you are essentially using the system clock as an RNG. This does not show much adverse affect on the newer computers, but would on the older.

I changed how often I called Randomize, and now Don is getting "normal" results.

I'm also working on getting a better RNG than the one native to VB.

John

[Igor]

[Parker]

> Do NOT buy a computer from a department
> store or a chain computer store or an office
> supply retailer. Find the Value Added
> Reseller (VAR) in your area patronized by
> the computer geeks and the professional
> computer technicians. The difference is
> night and day.

This is excellent advice. You will generally get a better system for your dollar, while avoiding the pitfalls of a proprietary system that Igor alluded to above. You will also enjoy a level of service unknown at the major chains.

Just look for one that has been around for a few years. If they have survived in today's economy, they are probably doing things right.

If you live in the San Diego area, I highly recommend Computer Circulation Center (corner of Ruffin and Clairmont Mesa Blvd., just west of I-15, behind Wells Fargo). I have been doing business with these guys for years, and they have always treated me right. (Unsolicited endorsement - I have no financial interest in this company.)