Delta lambda / lambda to which to shift individual spectral lines.
This is useful for making spectra for very distant objects and supercedes
velspec if it is not zero. Wavelength limits are not changed
If yes, a plot of the final output spectrum is displayed.
Cursor commands are activated, and a peak other than the maximum
can be chosen to be the center with the keystroke \fIp\fR. Hard copies
to stdplot may also be made using the \fI@\fR command.