Enhancing Plots (1)

Creating Plots

Enhancing Plots

Now that you know how to create single and overlaid plots, you can use the SYMBOL statement to enhance your plots by specifying plotting symbols, plot lines, color, and interpolation. (Interpolation is a technique for estimating values between plot points and drawing lines to connect the points.)

General form, SYMBOL statement:

SYMBOL<n> <option(s)>;

where

n is the symbol statement number (1 to 99). If no value for n is specified, SYMBOL1 is assumed.
option(s) indicates one or more options specified for each plot line.

SYMBOL statements remain in effect until you change them, cancel them, or end the SAS session.

Several SYMBOL statement options are shown below.

This option ... Specifies the ...
VALUE= plotting symbol
HEIGHT= height of the plotting symbol
INTERPOL= interpolation technique
WIDTH= thickness of the line in pixels
COLOR= color of plotting symbols or lines

This option ...	Specifies the ...
VALUE=	plotting symbol
HEIGHT=	height of the plotting symbol
INTERPOL=	interpolation technique
WIDTH=	thickness of the line in pixels
COLOR=	color of plotting symbols or lines

For example, the SYMBOL1 statement below specifies that

red stars (1 centimeter high) will be the plotting symbols
red smoothed lines (4 pixels wide) will connect the plotting symbols.

     symbol1 color=red value=star interpol=spline
             height=1 cm width=4; 
     proc gplot data=clinic.totals2000;
        plot therapy*month; 
     run;

The PROC GPLOT step produces the plot below.

Plot with SYMBOL statement options specified