plot-pdg     Plotting periodograms after tslist

 USAGE:     plot-pdg [ +T -tax-options [ +Y -yax-options ] + ] [options] pdg-file [pdg-file ...]
            plot-pdg [ +T -tax-options [ +YF yrange ytix ] + ] [options] pdg-file [pdg-file ...]
 PURPOSE:   After tslist ... -Epdgram.tse,PDG -N -n/$length -w pdg-file
                  tslist ... -Epdgram.tse,PDG -N -nFrqs     -w pdg-file
            make a log-log plot (dB vs log f)
            The axes scaling will depend on the first pdg-file.

            Use -tax and -yax-options to add space to the plot.
            +F and +FF are synonymous with +T and +TF, respectively.
            These -?ax options are transferred to axlim. Cf axlim -h
            e.g. -X0,1   or  -D1,1  (also  -f  or  -t ; avoid other axlim options!);
            For fixed axis range and annotation, use +TF and/or +YF
            Careful with +TF, the axis is log by default.
            Likewise with +T, extending the axis with -X requires big values (at least 1.0);
            consider -D. Again, consider axlim -h for help.
            A legend file may be supplied --- currently disabled

            Curve colours are assigned automatically.
 -D               - Decorate with bars at CW Sa Ssa -frequencies.
 -DS              - Decorate with Darwin symbols (uses ~/Ttide/etgtab/tide-spect.dat )
 -decore-color <color> GMT color code for the bars

 -p ps-file       - Default derived from the first pdg-file name.
 -L[d]            - Include a legend of pdg-file names (unstripped of pathnames).
 -L[d]f lgnd-file - A legend file consists of the pdg-file name in the first
                    column followed by legend text. 
                    Default is no legend.
                    With -Ld, decorate (file-name for plot title,
                    white background behind legend).
 -lin             - linear frequency scale (default is logarithmic).
 -f unit          - the frequency units in the input, default = cyc/h.
                    mHz, Hz, cyc/d  will scale the -D decoration.
 -ftxt text       - frequency label, default = Freq

 -y unit          - y-axis' units, default = dB
                    Both depend on the scaling at the tslist stage.
 -xlp x  -ylp y   - Legend position. Default is 0.1 and empty, respectively.
 -xls x           - Legend horizontal width, Default is 2. Height is automatic.
 -y <y-unit>      - Default dB
 -w width         - Plot the first curve once again with this line width.

 -C cpt           - Colour table, default = haxby

    PNGOUT        - the directory for the png-file, default ~/www/4me/

           plot-pdg +TF 1.85/1.87 a0.005f0.001 +YF -30/30 a10f1 + -DS -lin -f cyc/d \
                    -p o/g090615-OPNEND-1h-nnt-ochy.wr.pdg

           plot-pdg +T -X0,0.1 +Y -X0,1 + -p o/g100202-OPNEND-1h-new-wwf.ra.pdg
           plot-pdg +T -X0,0.1 +Y -X0,1 + -Lf tmp/tmp.legend -p tmp/tmp-*.pdg
  with tmp/tmp.legend (hand made)
           tmp-2.pdg lpef=2
           tmp-3.pdg lpef=3
As another example, see e.g. ~/OTEQ/ttgs.legend
  The last part of ~/OTEQ/bin/plot-tgg gives a nice example.

  Create a legend file with stripped file names in the second column:
           ls <expr> | sed 's|.*/||; s|\(.*\)|\1 \1|; s|\([^ ]*\)\([^.]*\).*|\1 \2|'
  Create a legend file with directory paths only:
           ls <expr> | sed 's|\(.*\)/\(.*\)|\2 \1|'