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How to Make a Simple Plot

To plot  the data in the database tables you have specified, select PLOT from the main option menu, enter the parameter or expression that you want plotted on each axis. The main plot menu lets you make various modifications to the retrieve request and to the display of the data. Entering ; at this menu causes the data to be retrieved and plotted.

   <3=MO;> Plot,Regress,...?    PL

   \* Options are:
     1) Y < IP >
     2) X < NE >
     3) Constraints < >
     4) Symbols < >
     5) Graph ranges  <Y: 0.0, 0.0, LIN> <X: 0.0, 0.0, LIN>

    Set?                         X 
    X axis?                      IP                           
    Set?                         Y TE 
    Set?                         ;
    Graph of TE vs IP            RETURN

Figure 1: Scatter plot

Figure 1 shows the graph of TE vs IP. When you enter RETURN, you go back to the main plot menu. To graph TE vs IP but with fixed scales and symbols distinguishing values of NE, you would do:

    Set?                       G
    Y range and type           1. 4.
    Y (LIN or LOG) <LIN>       ,
    X range and type           300 500
    X (LIN or LOG) <LIN>       ,
    Set?                       S
    Symbols?                   NE=2.5e19 NE=2.8e19 ;
    Set?                       ;
    Graph of TE vs IP

Figure 2: Rescaled scatter plot with symbol constraints

The graph is shown in Figure 2. At the bottom of the graph, LOCUS displays the database, tables, today's date, a sequence number, and the number of points retrieved. In parentheses, the number of points that lie below or to the left of the graph and the number of points that lie above or to the right of the graph are shown--both zero in this case.

Commands are available after the graph has been drawn. Enter ? in the graphics window immediately after the graph is drawn to see a complete list of commands which are described in section 2.6. For example, to get a least squares fit  to the data points, enter F--the equation of the fit, the correlation coefficient, and the variance are shown. A least squares fit can be gotten for logarithmic plots as well as linear. A polynomial fit can be gotten by entering the order of the polynomial instead of F, or 0 can be used to get a proportional fit. For more information about the fitting, see section 2.6.1.

If you enter RETURN at any of the axes or constraint prompts, you can get a list of the parameters and names of expressions in the tables you have selected:

    X axis?                      RETURN

        Table TESCAL
        IP            NE            SHOT          TE

        Expressions from XTESCAL
        IP_MAX        IP_ROUND      TAUE          TAUE_MS

next up previous contents index
Next: Using More Than One Up: An Introduction to Using Previous: Running LOCUS

Marilee Thompson
Fri Jul 11 17:05:56 EDT 1997