No space between the option flag and the associated arguments. Don't plot traces with zero rms amplitude. Multiply trace locations by scale before plotting. Default has location given by trace number. Override number of traces specified in reel header.
Negative velocity removes existing reduction.
Units should be consistent with offset in trace header and sample interval. Plot only traces whose location corresponds to a list given in filename . Order in which traces are listed is not significant - the entire space is checked for each trace.