## Getting Started Example 1 for PROC TRANSREG

```/****************************************************************/
/*          S A S   S A M P L E   L I B R A R Y                 */
/*                                                              */
/*    NAME: TREGGS1                                             */
/*   TITLE: Getting Started Example 1 for PROC TRANSREG         */
/* PRODUCT: STAT                                                */
/*  SYSTEM: ALL                                                 */
/*    KEYS: regression analysis, transformations                */
/*   PROCS: TRANSREG                                            */
/*    DATA:                                                     */
/*                                                              */
/* SUPPORT: saswfk                UPDATE: July 25, 2010         */
/*     REF: PROC TRANSREG, GETTING STARTED EXAMPLE 1            */
/*    MISC:                                                     */
/****************************************************************/

title 'Gasoline and Emissions Data';

data gas;
set sashelp.gas;
if fuel in ('Ethanol', '82rongas', 'Gasohol');
run;

ods graphics on;

* Request a Spline Transformation of Equivalence Ratio;
proc transreg data=Gas solve ss2 plots=(transformation obp residuals);
model identity(nox) = spline(EqRatio / nknots=4);
run;

* Separate Curves and Intercepts;
proc transreg data=Gas solve ss2 additive plots=(transformation obp);
model identity(nox) = class(Fuel / zero=none) |
spline(EqRatio / nknots=4 after);
run;

* Separate Intercepts;
proc transreg data=Gas solve ss2 additive;
model identity(nox) = class(Fuel / zero=none)
spline(EqRatio / nknots=4);
run;

* Separate Curves and Intercepts with Penalized B-Splines;
proc transreg data=Gas ss2 plots=transformation lprefix=0;
model identity(nox) = class(Fuel / zero=none) * pbspline(EqRatio);
run;

```