PROC GAM for y=s1(x1)+s2(x2)

[howchinh2]

Hi,
How can I write the code using PROC GAM for y=s1(x1)+s2(x2), where the intercept and linear terms are suppressed?

I have tried using model option noint but it gave error. 

proc gam data=mydata;

model y = spline(x1) spline(x2) / noint;

output out=pred predicted=f;

run;

The error message shows model statement didn't recognise noint option.

Please help.

Thank you.

[StatDave]

You might be able to get essentially what you want by using the EFFECT statement in a suitable modeling procedure rather than by using PROC GAM (or the newer and recommended PROC GAMPL). For example, the following fits a model like you describe to the diabetes data in the Getting Started example in the PROC GAM documentation using the EFFECT statement in PROC ORTHOREG. See the description of spline effects using the EFFECT statement in the Shared Concepts and Topics chapter of the SAS/STAT User's Guide.

proc orthoreg data=diabetes;
effect s1=spline(age/ basis=tpf(nopowers));
model logcp=s1/noint;
effectplot;
run;

[howchinh2]

Thank you so much for your advice. 

I will work on it. 

Thanks.