Documentation Example 1 for PROC TRANSREG


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/*          S A S   S A M P L E   L I B R A R Y                 */
/*                                                              */
/*    NAME: TREGEX1                                             */
/*   TITLE: Documentation Example 1 for PROC TRANSREG           */
/* PRODUCT: STAT                                                */
/*  SYSTEM: ALL                                                 */
/*    KEYS: regression analysis, transformations                */
/*   PROCS: TRANSREG                                            */
/*    DATA:                                                     */
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/* SUPPORT: saswfk                UPDATE: July 25, 2010         */
/*     REF: PROC TRANSREG, EXAMPLE 1                            */
/*    MISC:                                                     */
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ods graphics on;

title 'Gasoline Example';
title2 'Iteratively Estimate NOx, CpRatio, EqRatio, and Fuel';

* Fit the Nonparametric Model;
proc transreg data=sashelp.Gas solve test nomiss plots=all;
   ods exclude where=(_path_ ? 'MV');
   model mspline(NOx / nknots=9) = spline(EqRatio / nknots=9)
                                   monotone(CpRatio) opscore(Fuel);
run;

title2 'Now fit log(NOx) = b0 + b1*EqRatio + b2*EqRatio**2 +';
title3 'b3*CpRatio + Sum b(j)*Fuel(j) + Error';

*-Fit the Parametric Model Suggested by the Nonparametric Analysis-;
proc transreg data=sashelp.Gas solve ss2 short nomiss plots=all;
   model log(NOx) = pspline(EqRatio / deg=2) identity(CpRatio)
                    opscore(Fuel);
run;