The GCONTOUR Procedure

Example 4: Using Patterns and Joins

Procedure features:	COUTLINE, CTEXT, HAXIS, JOIN, LEGEND, PATTERN
Data Set	SWIRL
Sample library member:	GCTPATJN

This example demonstrates the differences between using lines and patterns to represent contour levels. The first PLOT statement generates a plot with lines representing contour levels.

Line Contour Levels

[Line Contour Levels]

The second PLOT statement specifies the PATTERN option to fill and color contour levels. Additional PLOT statement options outline filled areas in gray and specify green text for all text on the axes and in the legend.

Pattern Contour Levels

[Pattern Contour Levels]

The third PLOT statement uses the JOIN option to combine adjacent grid cells with the same pattern to form a single pattern area. Additional options enhance the plot by modifying the axes and framing the legend.

Contour Plot with Joined Cells

[Contour Plot with Joined Cells]

goptions reset=all border;

data swirl; 
    do x= -5 to 5 by 0.25;
       do y= -5 to 5 by 0.25;
          if x+y=0 then z=0;
             else z=(x*y)*((x*x-y*y)/(x*x+y*y)); 
          output; 
       end; 
    end; 
run;

title1 "Line Contour Levels";
footnote1 j=r "GCTPATR1";

proc gcontour data=swirl;
   plot y*x=z;
   run;
quit;

title1 "Pattern Contour Levels";
footnote j=r "GCTPATR2";

proc gcontour data=swirl;
   plot y*x=z / 
      ctext=green
      coutline=gray
      pattern;
   run;
quit;

title "Contour Plot with Joined Cells";
footnote j=r "GCTPATR3";

axis1 label=none 
    value=("-5" '' "0" '' "5")
    color=red 
     width=3;
  axis2 label=none 
     value=("-5" '' "0" '' "5")
     color=red  
     width=3;

legend1 frame;

proc gcontour data=swirl;
    plot y*x=z / 
        haxis=axis1
       join
       legend=legend1
       pattern
       vaxis=axis2;
   run;
quit;

Top of Page