Use the PLOTS(INTERPOLATE) Option in PROC TRANSREG
/****************************************************************/
/* S A S S A M P L E L I B R A R Y */
/* */
/* NAME: tregint */
/* TITLE: Use the PLOTS(INTERPOLATE) Option in PROC TRANSREG */
/* PRODUCT: STAT */
/* SYSTEM: ALL */
/* KEYS: regression analysis, transformations */
/* PROCS: TRANSREG */
/* DATA: */
/* */
/* SUPPORT: saswfk UPDATE: July 25, 2010 */
/* REF: PROC TRANSREG, DETAILS, INTERPOLATE */
/* MISC: */
/****************************************************************/
title 'Smoother Interpolation with PLOTS(INTERPOLATE)';
data a;
input c y x;
output;
datalines;
1 1 1
1 2 2
1 4 3
1 6 4
1 7 5
2 3 1
2 4 2
2 5 3
2 4 4
2 5 5
;
ods graphics on;
proc transreg data=a plots=(tran fit) ss2;
model ide(y) = pbs(x) * class(c / zero=none);
run;
data b;
set a end=eof;
output;
if eof then do;
y = .;
do x = 1 to 5 by 0.05;
c = 1; output;
c = 2; output;
end;
end;
run;
proc transreg data=b plots(interpolate)=(tran fit) ss2;
model ide(y) = pbs(x) * class(c / zero=none);
run;