st: tabodds command with 'if' option

[Sean Shu <sshu@hkpr.on.ca>]

Hi there,

I have a cross-sectional time series dataset. I want to find whether any 
trend is presented over the years for different categories. So I used 
tabodds command. But I want to apply the command for different category 
seperately. so I write the command syntax over the dataset attached:

> tabodds case year [fweight=freq][if cat = 1]
> tabodds case year [fweight=freq][if cat = 2]
...
> tabodds case year [fweight=freq][if cat = 5]

Can you tell what's wrong with it? and Do I need write syntax to loop 
the tabodds five time?

Thank you very much!

Sean Shu
HKPR District Public Health Unit
Ontario, Canada

Attachment: trend_fin.dta
Description: Binary data