22,16   		!Output formatting parameters.

General listing of options in PLT_SPEC Options are ordered under subject.
Associated with each option are requested inputs. Some inputs are not
prompted for, and can only be changed from their default values by specifying
them in the call. eg.

		       RD_MOD(OVER=T)

Such inputs are placed in [ ].

SVE and BOX file:
	Default is to write file MAIN_OPT_STR.sve
	Append sve=filename to write a new .sve file (no brackets)
	Type box=filename to write a .box file containing several .sve files
	Type .filename to read .sve file
	Type #filename to read .box file

        NB: RD_OBS and RD_OBS1 (etc) are presnetly treated as the same option,
            but write different sve files with different names.

Input/output:

    RD_MOD  	Read in a different model spectrum, and plot it. The existing
		  model spectrum is not corrupted unless OVER=.TRUE.
                [OVER] Read in new model spectrum replacing the existing
                  model spectrum. No plots are done.
                [SCALE] : Value to normalize PLOT data by [Logical].
			    (not done if OVER=T).

    RD_CONT  	Read in a model spectrum, and plot it. The existing
    		  model spectrum is not corrupted unless OVER=.TRUE.
	          This option can be used to read in a continuum.
	          (Similar to RD_MOD with OVER=.FALSE.)
		[WR] - Write data to file.
                [SCALE] : Value to normalize data by [Logical].
                     
    NORM        Read in a spectrum, and divide the present model spectrum
                  by it. The existing model spectrum is not corrupted.
		  [WR] - Write data to file.

    RD_OBS	READ in a OBSERVATION and plot it using existing switch
                  settings.
                [SCALE] : Value to normalize data by [Logical].
		[CLEAN] : Remove data points with zero flux. Useful for operating
			    on UV data[Logical].
		[SMOOTH]: Indicates whether data is to be smoothed. Only option 
			    presently available is HAN.
		[RAD_VEL]: Specifies a radial velocity. This option needs work, so
				don't rely on it.
	        [TREAT_AS_MOD] : Write observations into model vectors. The
                                   obs can then be reddened, or deredenned, 
                                   for example.
		[WR] - Write data to file.

X Axis Options
    LX		Switch between logarithmic and linear X-AXIS
    LOGX        (i.e. do opposite to current setting)
    LINX

    XU		Change units for X-axis. Options are:
    XUNITS	   Hz
		   um
		   Ang
		   keV
	           eV
		   km/s

Y Axis Options
    LY		Switch between logarithmic and linear Y-AXIS
    LOGY        (i.e. do opposite to current setting)
    LINY

    YU		   Change Y plot parameter. Options are:
    Y_UNITS 	      Flam    (ergs/cm^2/s/Ang)
		      FNU     (Jy)
		      NU_FNU  (ergs/cm^2/s)

Continuum flux options.
    FLAM	Plots model energy distribution:
	          The type of axes are determined by the X and Y axis
	          options.
	          E(B-V) and a distance are requested. Defaults are
		    zero and 1kpc.
    FNU		Same as FLAM
    WRFL	Same as FLAM except data written to unit 50. 
    BB		Black_body spectrum normalized by radius or flux.

    CUM		Plots cumulative luminosity as function of lambda.
    EBMV        Plots A(Lambda) as a function of X unit.
	          R_EXT --- (==A(V)/EBMV)
                  If R_EXT is non zero, the interstellar extinction
                   formulation of Clayton, Cardelli, and Mathis is used.
                  IF R_EXT is zero, the R_EXT is set to 3.1, and the
                    galactic extinction and LMC extinction laws summarized
                    by Howarth (1983, MNRAS, 203, 301) are used.


    ZAN		Output Zanstra parameters (Working??).
    MAG		Output continuum magnitudes to file (MAG).

Control Options:
    HZ_IN	Switches frequency input units to 10^15 Hz (def)
    KEV_IN	Switches frequency input units to KeV
    ANG_IN	Switches frequency input units to Angstroms
    XRAY_..	Switches on K-shell X ray opacities for CNO elements.

Miscellaneous options.
