Degree of Freedom for a categorical variable

hyous0001 — Mon, 22 Oct 2018 02:18:09 GMT

Hi;

I intend to make a 3-way interaction using the "Proc Genmod". For this purpose, I made the following variables:

EPU: a categorical variable which takes the value of 1,2 or 3 and I made it using a continuous variable.

M2CAT: a categorical variable which takes the value of 1,2 or 3 and I made it using a continuous variable.

MM: a continuous variable.

The model is as follow:

proc genmoddata=rr;
class fyear sic2 ;
model capas= epu|mm|m2cat C1 C2 C3 C4 sic2;
repeated subject=fyear ;
store capascont;
run;

When I run the model, it shows the degree of freedom (DF)=1 for EPU and M2CAT. It has caused me a problem since it doesn't show me the interaction of each category with my continuous variable and it seems that SAS treats these categorical variables as a continuous variable. I tried to change the format using the PROC FORMAT but the results stay the same. The problem remains even when I use PROC GLM instead of proc Genmod:

proc glm=rr;
class fyear sic2 ;
model capas= epu|mm|m2cat C1 C2 C3 C4 sic2;
run;

I would be grateful if you could help me with this.

Thanks

Re: Degree of Freedom for a categorical variable

PaigeMiller — Mon, 22 Oct 2018 12:33:51 GMT

If EPU and M2CAT are categorical, you need to include them in the CLASS statement.

Re: Degree of Freedom for a categorical variable

hyous0001 — Mon, 22 Oct 2018 16:03:37 GMT

You're right, it worked! Thank you dear Paige.

I just got confused since it is exactly what we need to do to add a fixed effect!

topic Degree of Freedom for a categorical variable in New SAS User

Degree of Freedom for a categorical variable

Re: Degree of Freedom for a categorical variable

Re: Degree of Freedom for a categorical variable