/* This is a subset of the pens data from the UCI archive (the same data used in the 
SAS course DMDT)   X1-X16 are 16 pen positions for subjects writing on a pressure 
sensitive pad. Digit is the digit they were writing. */
data next; 
infile 'a:\minertalk\pens.txt';
input x1-x16 digit;
 nine=(digit=9);
cards;
proc print uniform noobs data=next(obs=800); run; 
proc princomp noprint out=digits; var x1-x16; 
proc print data=digits(obs=5); 
proc logistic; 
  model nine=prin1-prin16/selection=backward; run;

  proc gplot; plot prin1*prin2=digit; 
  symbol1 v="0" c=red i=none; 
  symbol2 v="1" c=blue; 
  symbol3 v="2" c=gray; 
  symbol4 v="3" c=tan; 
  symbol5 v="4" c=orange; 
  symbol6 v="5" c=cyan; 
  symbol7 v="6" c=black; 
  symbol8 v="7" c=blue; 
  symbol9 v="8" c=green;
  symbol10 v="9" c=purple;
 run; 
  ************* Macro to plot sets of 3 digits *************; 
  %macro plot3(p1, p2, pref, d1, d2, d3); 
    proc gplot; plot &pref.&p1 * &pref.&p2=digit; 
    where digit in (&d1 , &d2, &d3 ); 
	symbol1 v="&d1" c=red i=none; 
	symbol2 v="&d2" c=blue; 
	symbol3 v="&d3" c=green; 
	title h=1.5 j=left "&pref.&p1 by &pref.&p2 for digits &d1, &d2, &d3 ";
%mend ; ****************************************************;
 
 ** Plot some triples: use (d1<d2<d3) **; 
 %plot3(1,2, prin, 1, 6, 9); 
 %plot3(1,2, prin, 2, 3, 8); 
 %plot3(3,4, prin, 2, 3, 8); 
 %plot3(1, 10, X, 2,7,9); 
run;