This page performs a discrete fast Fourier transform on real data
and plots both the input waveform and the 'power' output. Since the
algorithm is based on a fast Fourier transform (FFT), the number of
input points is limited to a power of two. Points beyond a power of
two are discarded; for example, if 100 points are input, only 64
(2^6) points are used. The output includes a listing of the input as
a check, and the sine and cosine components for the transform. The
'power' is calculated as the square root of the sum of the squares
of the sine and cosine component; these are the values plotted on
the second graph. Since the listings are delimited with tab
characters, they can readily be exported into a spreadsheet.
Graphing uses the Canvas tag, which may not be available in some
within the source of the page.
Jeffrey Clymer -- July 4, 2011. Revision 2, July 6, 2011 -- Email -- Homepage