Many digits of pi again

[Katie Wasserman]

(01-27-2014 06:44 AM)Benoit Maag Wrote:  Some programs manage 6 digits per memory, some 7 or 8. I suspect the choice is based on a combination of internal precision of calculation and the number of terms calculated. Is there a thread describing how to select the number of digits per memory? Or can someone clarify that? (Katie?)

Yes, you've got that exactly right.

The argument gos something like this:

I have a 10-digit calculator so I can fit 8 digits into each memory register allowing for multiplication/division of up to 2 digits. So now I can calculate up to 1000 digits. But at XXX digits I need 3 digits in my multiplication/division so I can only use 7 digits per register.

You can write a simple formula for this but there are idiosyncrasies of each calculator that need to be taken into consideration and certain programing tricks allow for more (or less) precision, etc.. It's not easy to figure out the maximum number of digits unless you error on the side of caution or do it experimentally.

The 16C is a fun calculator to play this game on since it gives you such nice control over the word size.