Error message: normal distribution with log link

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VBMHealthEcon
Posts: 7
Joined: Tue Jul 09, 2013 3:09 pm

Error message: normal distribution with log link

Post by VBMHealthEcon »

Hello,

I'm trying to run a three-level model using a normal distribution with a log link. However, I receive the following error message: "==: operator invalid
r(198);"

I also receive this message when I try to run a three level model using data available on your website in the "Examples" page in order to double-check if the issue is with my data.

I have no problem running the model if I use another distribution e.g. the Poisson with a log link either with my own data or your data.

Is it possible to use a log link with a normal distribution or could something else be causing the problem?

Many thanks,
Valerie
ChrisCharlton
Posts: 1384
Joined: Mon Oct 19, 2009 10:34 am

Re: Error message: normal distribution with log link

Post by ChrisCharlton »

MLwiN currently only allows the identity link for Normal models, so if you hadn't got the error in Stata it still wouldn't have fitted the model. We should probably provide a more informative error message when this is attempted, so I will try to update this in later versions.
VBMHealthEcon
Posts: 7
Joined: Tue Jul 09, 2013 3:09 pm

Re: Error message: normal distribution with log link

Post by VBMHealthEcon »

OK - good to know. Thanks for your prompt response.

Valerie
GeorgeLeckie
Site Admin
Posts: 432
Joined: Fri Apr 01, 2011 2:14 pm

Re: Error message: normal distribution with log link

Post by GeorgeLeckie »

Hi Valerie,

Can you not just log transform your dependent variable and then proceed as normal

. generate newdepvar = log(olddepvar)

. runmlwin newdepvar...

Best wishes

George
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