Does this mean my dataset has too few observations?

I ran a GLM regression with 5 indepedent variables. My dataset contains 238 observations and I got error message like this:

Warning: Regression design matrix is rank deficient to within machine precision. > In TermsRegression>TermsRegression.checkDesignRank at 98 In GeneralizedLinearModel>GeneralizedLinearModel.fit at 1174 In fitglm at 133

Does this mean I have too few observations? Because if I have 347 observations, it runs fine without any complaints.

Answer 1

[Star Strider]

My guess is that there is something strange about Observation #238. Check it to see that all the data in it are valid.

[TingTing]

Hi, thanks a lot for reply! I wonder why you mentioned Observation #238. I plotted out leverage and ¤238 does not seem to be outlier. While #20 seems to be outlier. I excluded #20 and still got the same error message...

[Star Strider]

My point is that there is something about the added observation that is crashing your design matrix. I would check to see that all the data in that observation are valid.