This page provides a short and simple program for any student with an account on the departmental server to make use of the discrete fast Fourier transform (discrete FFT or DFFT) to analyze a data file of N {time,amplitude} pairs, one pair per line, tab delimited (i.e., a single tab character between the time and amplitude values). The N transform pairs are computed and written to files for plotting. The power spectrum, |Y_i|**2 is also computed and a plot is executed for the user using the interactive graphics package xmgrace.
The input data set should look like:
"Descriptive title of your choice..." Time(s) Voltage (V) 0.0000 2.427 0.0004 2.388 0.0008 2.349 0.0012 2.315 . . . . . . 24.9428 2.363 24.9432 2.329 24.9436 2.315
Download this file into the directory where you have stored your data file. Then open a console or shell window and type the following: tar -zxf tlg_dfft_download.tgz and hit the enter key. List ("ls" enter) the contents of your directory and make sure that the files powSpec.par and dfft_tlg.pl are there. If they are, then invoke the Perl script by typing: perl dfft_tlg.pl and hit the enter key. Enjoy.
This page designed and maintained by t.l. gibson