TRAIL N1 N2 C1 C2 XT A1 A2 NBIN -- Plots trailed spectrum on greyscale
devices. Use COLOUR to set look up table on
devices which support it.
TRAIL will provide valiues covering the whole of the first valid spectrum
as the defaults the first time a given mode of X axis is used. The
upper and lower limits of the greyscale can also be determined automatically
(see below).
NB: If you are using the STARLINK PGPLOT you can only get colour by calling
the command 'colour' after 'trail'. You will also not be able to make
colour PostScript plots. Get onto to PGPLOT 5.0 asap!
Parameters:
N1 -- Slot number of first spectrum to plot.
N2 -- Slot number of last spectrum to plot.
C1 -- Flux level to plot as lowest colour index (usually dark)
C2 -- Flux level to plot as highest colour index (usually bright)
NB If you set C1=C2 the plot will be scaled from the lowest to
the highest value. If in addition C1=C2=0. then the autoscaled
values will be set as the defaults for next time otherwise the
autoscaling remains on.
XT -- X-axis type (W=wavelength,V=velocity,P=pixel)
A1 -- W=start wavelength, V=central wavelength, P=start pixel
A2 -- W=end wavelength, V=km/s/pixel, P=end pixel
NBIN - Number of output bins.
This command belongs to the classes: display , binary , time_series