OPTIONS PS=66 LS=72 NODATE NONUMBER;

******************************************;
*** Example 1: PATH OF STEEPEST ASCENT ***;
******************************************;

DATA IN; INPUT X1 X2 Y @@; CARDS;
 -1 -1 39.3   -1  1 40.0    1 -1 40.9    
  1  1 41.5    0  0 40.3    0  0 40.5    
  0  0 40.7    0  0 40.2    0  0 40.6

PROC GLM DATA=IN;
     MODEL Y = X1 X2 / SS3 SOLUTION;
TITLE 'Example 1:  PATH OF STEEPEST ASCENT';

PROC RSREG DATA=IN;
     MODEL Y = X1 X2 / LACKFIT;
RUN;

DATA INB; INPUT X1 X2 Y @@; CARDS;
 -1 -1 76.5   -1  1 77.0    1 -1 78.0    
  1  1 79.5    0  0 79.9    0  0 80.3    
  0  0 80.0    0  0 79.7    0  0 79.8

PROC GLM DATA=INB;
     MODEL Y = X1 X2 / SS3 SOLUTION;
TITLE 'Example 1:  PATH OF STEEPEST ASCENT #2';

PROC RSREG DATA=INB;
     MODEL Y = X1 X2 / LACKFIT;
RUN;
/*
***********************************;
*** Example 2:  PATH OF DESCENT ***;
***********************************;

DATA IN; INPUT X1 X2 X3 X4 COST @@; CARDS;
-1 -1 -1 -1 625    1  1 -1 -1 670
 1 -1  1 -1 663    1 -1 -1  1 654
-1  1  1 -1 648   -1  1 -1  1 634
-1 -1  1  1 692    1  1  1  1 686
 0  0  0  0 680    0  0  0  0 674
 0  0  0  0 681

PROC GLM DATA=IN;
     MODEL COST = X1 X2 X3 X4 / SS3 SOLUTION;
TITLE 'Example 2: PATH OF STEEPEST DESCENT';

PROC RSREG DATA=IN;
     MODEL COST = X1 X2 X3 X4 / LACKFIT;
*/
RUN;