[5044] in cryptography@c2.net mail archive
Re: number of ones
daemon@ATHENA.MIT.EDU (Tom Weinstein)
Thu Jul 1 13:21:57 1999
Date: Wed, 30 Jun 1999 21:47:11 -0700
From: Tom Weinstein <tomw@geocast.com>
To: Mike Stay <staym@accessdata.com>
Cc: coderpunks@toad.com, cryptography@c2.net
Mike Stay wrote:
>
> I wrote
> > What's the average number of ones in a randomly-chosen N-bit number?
>
> Duh..
> Sorry, I was thinking of the average number of bits that change on
> increment. The answer's obviously N/2 for the above.
N-1
__ 1
\ ---
/__ 2^n
i=0
which is just the sum of the probabilities for each bit to change.
--
What is appropriate for the master is not appropriate| Tom Weinstein
for the novice. You must understand Tao before | tomw@geocast.com
transcending structure. -- The Tao of Programming |
