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			       DG

      DISPGAL is a module which plots galaxian photometric and structural
 parameters and fits various  curves to them.  It requires data to be in 
 a file of type 3.

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 Enter an option:                              25-NOV-1991 16:49:00.16
 OPTION=DG                                                        
 DISPGAL, Version 2
 Enter a command:
      R   = Plots radius-parameter against magnitude (default)
      S   = Plots surface brightness against magnitude
      T   = Plots surface brightness against radius-parameter
      M   = Plots the mean error against magnitude
      D   = Displays the differential luminosity function
      I   = Displays the integrated luminosity function
      I2  = Displays two integrated luminosity functions
      C2  = Plots the integrated color (first file minus second) against
            magnitude of the first file
      C2C = Plots the magnitude of one file against that of another
      G2  = Plots color gradient and  color delta against magnitude or against
            each other as derived from two files
      S2  = Plots surface brightness color against  magnitude
      S2S = Plots surface brightness of one file against that of another
      A2  = Plots the average radius-parameter against magnitude
      R2  = Plots the ratio of radius-parameter against magnitude
      R2R = Plots the radius-parameter of one file againstthat of another
      M2  = Plots the ratio of mean error against magnitude
 COMMAND=G2
 Do you want to plot a curve through the data?  (default = Y)
 CURVE_FIT=
 T			    ....Our intention is to plot a straight line
				by least squares
 Enter the lower limit of acceptance for the radius-parameter:  (default = 0.0)
 LOWER_LIMIT=.001	    ....This file contains some faint magnitudes 
				without radius parameters, so we must 
				put in this limit
 Enter the lower limit of acceptance for the magnitude:  (default = -100.00)
 LOWER_LIMIT_MAGNITUDE=
  -100.000    
 Enter the upper limit of acceptance for the magnitude:  (default = 100.00)
 UPPER_LIMIT_MAGNITUDE=18    ....The very faintest data is too noisy
 Open the first data file to be plotted
 Enter the file name:  (default = last entry)
 FILE_21=G022152	    ....The blue parameters in a file of type 3
 Open the second data file to be plotted
 Enter the file name:  (default = last entry)
 FILE_22=G022151	    ....The red parameters
 Enter a choice:
      GH = Dimensionless color gradient (linear in r) for the Hubble formula
           against magnitude.  The files must contain Hubble a's
      DH = Color delta for the Hubble formula against magnitude (default)
           The files must contain Hubble a's.
      DV = Color delta for the de Vaucouleurs formula against magnitude
           The files must contain de Vaucouleurs r's.
      HV = Color delta for the Hubble and de Vaucouleurs formulas against
           each other
  
 CHOICE=DH
 Enter the radius as a multiple of the radius parameter:  (default =1)
 RADIUS=
   1.00000    		    ....The color delta is calculated as the
				difference in color between center and,
				in this case, 1 radius parameter away
				from the center.
 Do you wish to plot the error bars?  (default = Y)
 ERROR_BARS=
 T
 ID             MH COLOR DELTA
 17           -0.6674 +- 0.1095
 59            0.2666 +- 0.0764
 70           -0.0703 +- 0.0340
 72           -0.0216 +- 0.0584
 85           -0.0663 +- 0.0624
 104          -0.0459 +- 0.0945
 114          -0.0050 +- 0.0895
 123          -0.1680 +- 0.0751
 126           0.0096 +- 0.0590
 129          -0.3938 +- 0.0489
 144           0.3511 +- 0.0805
 147          -1.1310 +- 0.1205
 161          -0.1816 +- 0.0952	    ....Here are the color deltas and
					their errors

 Enter the degree of the polynomial fit:  (default = 0)
 DEGREE=1
 Do you want to force the curve through the brightest point?  (default = N)
 FORCE=
 F
 Do you want to fix the constant?  (default = Y)
 FIX_CONSTANT=N
 Do you want to fix the slope?  (default = Y)
 FIX=N
 ORDER COEFFICIENT MEAN ERROR
  0   0.13363      2.8492    
  1  -0.17197E-01 0.16486	    ....The least squares parameters
 Enter the plot devices:
      G  = Graphics terminal (VT100/Retrographics and Visual 550, default)
      G1  = Graphics terminal (GraphOn)
      G2  = Graphics terminal (Codonics)
      G3  = Graphics terminal (Micro-term)
      F   = File
      T   = Tektronix 4662 flat bed plotter (1200 baud)
  
 DEVICES=
 G                             
			    ....The plot looks OK

 Do you want to plot the residuals about the mean fit?  (default = Y)
 RESIDUALS=
 T
 Enter the bin size in magnitudes:  (default = 0.10)
 INTERVAL=
  0.100000    
 Enter the plot devices:
      G  = Graphics terminal (VT100/Retrographics and Visual 550, default)
      G1  = Graphics terminal (GraphOn)
      G2  = Graphics terminal (Codonics)
      G3  = Graphics terminal (Micro-term)
      F   = File
      T   = Tektronix 4662 flat bed plotter (1200 baud)
  
 DEVICES=
 G			    ....There is a slight assymmetry

			    ....We could go back and change any 
				input parameter with the .DG(KEYWORK=...)
				option.  We could also interact with the
				plot to produce a camera ready copy.

			    ....Here is another example of option DG.
 Enter an option:                              25-NOV-1991 16:42:57.19
 OPTION=DG                                         
 DISPGAL, Version 2
 Enter a command:
      R   = Plots radius-parameter against magnitude (default)
      S   = Plots surface brightness against magnitude
      T   = Plots surface brightness against radius-parameter
      M   = Plots the mean error against magnitude
      D   = Displays the differential luminosity function
      I   = Displays the integrated luminosity function
      I2  = Displays two integrated luminosity functions
      C2  = Plots the integrated color (first file minus second) against
            magnitude of the first file
      C2C = Plots the magnitude of one file against that of another
      G2  = Plots color gradient and  color delta against magnitude or against
            each other as derived from two files
      S2  = Plots surface brightness color against  magnitude
      S2S = Plots surface brightness of one file against that of another
      A2  = Plots the average radius-parameter against magnitude
      R2  = Plots the ratio of radius-parameter against magnitude
      R2R = Plots the radius-parameter of one file againstthat of another
      M2  = Plots the ratio of mean error against magnitude
 COMMAND=
 R  
 Do you want to distinguish those galaxies within a
 certain distance from a defined center?  (default = N)
 DISTINGUISH=
 F
 Enter the lower limit of acceptance for the radius-parameter:  (default = 0.0)
 LOWER_LIMIT=.001		    ....Some galaxies may not have radius 
					parameters
 Enter the lower limit of acceptance for the magnitude:  (default = -100.00)
 LOWER_LIMIT_MAGNITUDE=
  -100.000    
 Enter the upper limit of acceptance for the magnitude:  (default = 100.00)
 UPPER_LIMIT_MAGNITUDE=
   100.000    			    ....We'll plot them all
 Open the data file to be plotted
 Enter the file name:  (default = last entry)
 FILE_21=G022152
 The centroid of the X values is:     18.9605
 The centroid of the Y values is:     -0.8665
				    ....This gives us a feel for the starting
					values for the nonlinear least squares
					fit about to be done.
 The plot contains  119 points
 Do you want to plot a single curve through the data?  (default = N)
 CURVE_FIT=
 F
 Enter a choice:  A = Solves for m' and log(r') and plots the result (default)
                  B = Solves for m',log(r'), and the slopes, and plots the result
                  C = No fitting
  
 FIT_CHOICE=B
 Enter the weighting scheme:
      E = Equal weights (default)
      M = According to mean error
 WEIGHTING_SCHEME=
 E
 Enter the estimates for m' and log(r'):
 ESTIMATES=18.9 0.9		    ....From above
 m' =  17.8686 +-   0.5399	    ....This is the magnitude of the 
					intersection of two straight lines.
					Other parameters of the fit and their
					errors will appear on the screen.
	
 Mean error for an observation of average weight =   0.1816
 Enter the plot devices:
      G  = Graphics terminal (VT100/Retrographics and Visual 550, default)
      G1  = Graphics terminal (GraphOn)
      G2  = Graphics terminal (Codonics)
      G3  = Graphics terminal (Micro-term)
      F   = File
      T   = Tektronix 4662 flat bed plotter (1200 baud)
  
 DEVICES=
 G                             
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