Overlay plot with different number of points

[Doug]

I have a scatter plot upon which I must overlay three other items:

1. Centroid value of X and Y (one value with marker)

2. A circle +/- 2.5 units of the centroid

3. A circle of +/-5.0 units of the centroid

What is the most effective way of doing this?

[ballardw]

Which procedure do you plan on using?

Depending on procedure and version of SAS the second 2 are probably easiest with an annotate data set as you specify a a coordinate and radius for a circle. Which would require about 3 lines of code. Look at the %Circle macro in the annotate facility.

[Doug]

I originally planned to use SGPLOT  - the software version I have is 9.2 TS2M3

[Reeza]

GTL might be a good option if there's an easy way to draw a circle in it.

[ballardw]

Simplest I can think of:

data junk;

x = 5; y=5;

run;

proc sgplot data=junk;

scatter x=x y=y /markerattrs=(symbol=circlefilled) name='yes';

scatter x=x y=y /markerattrs=(symbol=circle size=25mm) name='no';

scatter x=x y=y /markerattrs=(symbol=circle size=50mm) name='no2';

keylegend 'yes' /title='Legend';

run;

The size and units would likely change depending on the size of your final display and you may want to play with axis defintions to make it prettier.

[DanH_sas]

If circles are not important, you can use XERRORUPPER/LOWER and YERRORUPPER/LOWER to show the +/-2.5 and +/-5.0 limits. You should need only two scatter overlays to show these limits, the first scatter can show the real point and the +/- 2.5 limits. The code will look something like this:

proc sgplot data=somedata nocycleattrs;

scatter x=x y=y / xerrorupper=xulimit50 xerrorlower=xllimit50 yerrorupper=yulimit50 yerrorlower=yllimit50 markerattrs=(size=0);

scatter x=x y=y / xerrorupper=xulimit25 xerrorlower=xllimit25 yerrorupper=yulimit25 yerrorlower=yllimit25;

run;

[Doug]

Dan,

Circles are kind of important since they are the companion to tables which show the actual counts

Any thoughts?

[Reeza]

Still say GTL

From the docs:

SAS(R) 9.3 Graph Template Language: User's Guide

[DanH_sas]

About how many scatter points are involved?

[Doug]

Probably about 50 per plot  - I don't have SAS 9.3 will the 9.3 GTL still work?

[ballardw]

Or perhaps proc gplot with a bubble plot with multiple requests overlayed.

[DanH_sas]

If you're going to use the ODS Graphics systems to do this at SAS 9.2, the only way that comes to mind (warning: this is brute force) is to use ELLIPSEPARM statements in GTL. You would have to write a macro loop to generate an ELLIPSEPARM statement for each circle needed in the plot. Here is some pseudo-code for the idea:

proc template;

define statgraph myscatter;

begingraph;

layout overlay;

  scatterplot x=x y=y;

  %do %p=1 %to numberOfCircles;

       ellipseparm semimajor=%unit semiminor=%unit slope=0 xorigin=%x yorigin=%y;

  %end;

endlayout;

endgraph;

end;

run;

proc sgrender data=somedata template=myscatter; run;