math & physics
paul0n0n at August 30th, 2009 23:13 — #1
How do you do it?
Here is an example of what I mean.
q = "0.2893798172383982716"
other then doing long division how do you find, say, 7 in q. Or rather is there a formula for finding, if n = 5 the outcome would then be 3 in
q. or if n = 13 the outcome would be 8.
why would i want to do this? just cause, i guess, asking and looking at things.
reedbeta at August 31st, 2009 01:41 — #2
Well, you know how to do long division, don't you? Just start dividing and keep going until you get to the desired digit.
alphadog at August 31st, 2009 15:20 — #3
Depends on how far in you want to go. Reedbeta's idea is KISS for low n's. But, if you want mathematical formula (cuz it's getz the chicks, right? Right!?!) a fancy way to get it is that the nth digit of a/b is the 1st digit of (10\\^(n-1)a mod /b, a.k.a. floor(10 * (10\\^(n-1)a mod B) / B) mod 10.
paul0n0n at August 31st, 2009 22:32 — #4
That is what I was looking for. And yes it gets chicks!
poita at September 7th, 2009 07:20 — #5
Convert to a string and then just index it
I can't imagine any situation where this would actually be a performance bottleneck.