/* EXAMPLE 3.8.1 */
options ls=80;
FILENAME DIABETIC 'T3_4_DIABETES.dat';
DATA DIABETES;
  INFILE DIABETIC;
  INPUT subject Weight Fasting Glucose Insulin Resist;
PROC IML;
  USE DIABETES;
  TITLE 'EXAMPLE 3.8.1';
  READ ALL VAR{Weight Fasting Glucose Insulin Resist} INTO X;
  N = NROW(X);
  MEAN = 1/N*X`*J(N,1);
  YBAR = MEAN[1:2];
  XBAR = MEAN[3:5];
  S = 1/(N-1)*X`*(I(N)-1/N*J(N))*X;
  Syy = S[1:2,1:2];
  Syx = S[1:2,3:5];
  Sxx = S[3:5,3:5];
  Sxy = S[3:5,1:2];
  PRINT YBAR, XBAR, Syy  Syx, Sxy  Sxx;
  print x;
ENDSAS;