The former version of the overlay-file command is still present as
ov. ``o'' stands for ``old''. This command loads a file,
changes the current buffer, and plots (in blue) the new data set over
the former current buffer (in yellow), whithout recomputing the
limits of the plot (unlike the new overlay command). This can be repeated to plot
multiple data sets.
ov3 are also
available load SWV data.
See also the new overlay command and mark command.