Power spectrum

spectrum [-f# -w# -o outfile -l# -x# -c# -V# -h] file(s)

-f sampling rate (e.g. in Hz, default 1.)
-w frequency resolution (e.g. in Hz, default 1/N)
-l number of values to be read (all)
-x number of values to be skipped (0)
-c column to be read (1 or file,#)
-o output file name, just -o means file_sp
-V verbosity level (0 = only fatal errors)
-h show this message

Computes a power spectrum by binning adjacent frequencies according to the option -w. Output file file_sp (frequency, spectrum).