Re: Unidentified subject!

[John Day]

At 01:44 PM 11/26/00 -0800, Abhra Haldar wrote:

> I have a file made up of thousands of
> characters a's, b's, c's d's. I need to know how to open this file,
> divide it into chunks of 2048 characters, and take the Fast Fourier
> Transform of each of these segments. Can anyone help? Thanks

I'm not sure what you want to achieve. Fourier transforms can't be
obtained directly from character streams. Perhaps you could compute the
densities of each character over the range of the file. You would
need to determine some appropriate bin-size and accumulate counts in each
bin for each type of symbol. These density counts correspond to a kind of
spatial amplitude, so if you took the Fourier transform of these
densities you would obtain a measure of spatial frequencies of the
density space.

Does that make any sense? 

John Day
Staff Scientist
Computer Science Innovations
http://www.csi.cc/Šþjday