- The `PLOT` Command:
  - `PLOT` is typically run with one or more files as an input.
  - To input multiple files, separate each file by a bar character (`|`).

        nM> plot world.shp|cities.prm

  - Attributes for each layer can be changed in line with the `LAYER={...}` qualifier.

        nM> plot world.shp{TAG=COUNTRIES,LAYER={OPAQ=0,LABEL=NAME}}|&
                     cities.prm{LAYER={COLOR=RED}}

    In the above example the qualifiers `LAYER={OPAQ=0,LABEL=NAME}` tells the plot layer to make the opaqueness zero (i.e. transparent) and to show a label on the readout with the `NAME` of the country.
  - By default layer names are automatically set to match the root name of the file. this can be overridden using the `TAG=` qualifier.
    - For example: Because of duplicate tags, only one of files shows up.

          nM> plot world.shp{LAYER={OPAQ=0}}|world.prm

    - This will work.

          nM> plot world.shp{TAG=SHP,LAYER={OPAQ=0}}|world.prm{TAG=PRM}

  - In order to use messages, one must add the `/msgid=` switch. (This is discussed more in the module on Macros.)
  - The `PLOT` command takes in a number of command line parameters allowing customization of the plot.
    - Most of these options are settable using `reg.<id>.<option>`.
    - A few examples:
      - Setting Y-axis limits (`Y1`, `Y2`).

            nM> plot/bg/id=myplot fftdemo.prm Y1=50 Y2=150

        or

            nM> plot/bg/id=myplot fftdemo.prm
            nM> set reg.myplot.y1 50
            nM> set reg.myplot.y2 150

      - Setting the view of a map.

            nM> plot/bg/id=myplot nxm.sys.dat.world.prm|cities.prm view=MERCATOR
            nM> set reg.myplot.view LATLON
            nM> set reg.myplot.view GEO