Proc GAM

[deleted_user]

I'm trying to fit a generalized additive model as follows:

proc gam data=dataset;
class DOW season holiday;
model deaths=param(DOW season holiday)
spline(date)
spline(temperature)
spline(humidity)
spline(NO2)
spline(Ozone)
spline(SO2)
spline(PM25)
spline(PM10) / dist=Poisson method=gcv nodev=norefit;
output out=dataset_out p;
run;

However, I keep getting an error message that states, "The backfitting algorithm diverged for this model."

What does this mean and how can I fix it? Thanks!

[deleted_user]

My hunch is that, Proc GAM may not be able to fit the non-linear curve. Try simplying the model by including less predictor variables..not sure if this will work