Analysis of a Blocked Response Surface Design
/****************************************************************/
/* S A S S A M P L E L I B R A R Y */
/* */
/* NAME: RSREGRDG */
/* TITLE: Analysis of a Blocked Response Surface Design */
/* PRODUCT: STAT */
/* SYSTEM: ALL */
/* KEYS: response surface methods, */
/* PROCS: RSREG */
/* DATA: Example in Myers (1976), pp. 189-193. */
/* */
/* SUPPORT: RDT UPDATE: January 2010 */
/* REF: Myers, Raymond H. (1976), "Response Surface Metho- */
/* dology", Blacksburg, Virginia: Virginia Poly- */
/* technic Institute and State University. */
/* MISC: */
/* */
/****************************************************************/
/*
/ The data is a central composite design in two factor variables
/ X1 and X2 and response variable Y. The design has been situa-
/ ted into two blocks orthogonal to the linear and quadratic
/ terms of the model.
/---------------------------------------------------------------*/
data A;
input Block X1 X2 Y;
datalines;
-1 -1.0 0.000 61.8
-1 0.5 0.866 86.0
-1 0.5 -0.866 86.3
-1 0.0 0.000 97.1
-1 0.0 0.000 95.9
1 -0.5 0.866 72.9
1 -0.5 -0.866 61.3
1 1.0 0.000 92.3
1 0.0 0.000 91.5
1 0.0 0.000 89.7
;
/*
/ Sort by the independent variables so that we can examine
/ lack-of-fit.
/---------------------------------------------------------------*/
proc sort;
by block x1 x2;
run;
/*
/ Analyze by declaring BLOCK to be a covariate rather than a
/ factor variable: the ridge of maximum response will be
/ computed for an "average" block (see the documentation for
/ RSREG on the treatment of covariates in the ridge analysis.)
/---------------------------------------------------------------*/
proc rsreg;
model y = block x1 x2 / covar = 1 lackfit;
ridge max;
run;