Subsetting data breaks GLM

Question

I have a GLM Logit regression that works correctly, but when I add a subset argument to the GLM command, I get the following error:

invalid type (list) for variable '(weights)'.

So, the following command works:

glm(formula = A ~ B + C,family = "binomial",data = Data)

But the following command yield the error:

glm(formula = A ~ B + C,family = "binomial",data = Data,subset(Data,D<10))

(I realize that it may be difficult to answer this without seeing my data, but any general help on what may be causing my problem would be greatly appreciated)

Answer 1

Try subset=D<10 instead (you don't need to specify Data again, it is implicitly used as the environment for the subset argument). Because you haven't named the argument, R is interpreting it as the weights argument (which is the next argument after data).