Unhelpful Error

[akgold]

Accidentally tried to do something stupid in vignette, but error message is unhelpful. Trying to specify that you want margins of continuous variable without at list.

Error message: Error in poly(age, 2) : 'degree' must be less than number of unique points

Code:

data(margex)

g <- glm(y ~ poly(age, 2)*sex , data = margex)
summary(g)
modmarg::mod_marg2(g, var_interest = "age")

[akgold]

It looks like this is a more general error. Running at with polynomial term seems to break.

data(margex)

g <- glm(y ~ poly(age, 2)*sex , data = margex)
modmarg::mod_marg2(g, var_interest = "treatment", type = "effects", 
                   at = list(age = seq(20, 60, 5)))

Error: Error in poly(age, 2) : 'degree' must be less than number of unique points

[anniejw6]

So fascinating...

data(margex)

# Fails to run
g <- glm(y ~ poly(age, 2) * sex , data = margex)
modmarg::mod_marg2(g, var_interest = "sex", "effects", 
                   at = list(age = seq(20, 60, 5)))

# Runs
g <- glm(y ~ poly(age, 2, raw = T) * sex , data = margex)
modmarg::mod_marg2(g, var_interest = "sex", type = "effects", 
                   at = list(age = seq(20, 60, 5)))

[anniejw6]

This makes sense to me intuitively insofar as poly (with raw set to F, which is the default) creates orthogonal vectors, and you can't really do that for a constant. Not sure how to deal with the error...

[akgold]

Add something to error that says You may be seeing this error because you used the poly() function and did not specify the option raw = T`? Just so that people have some idea how to fix...

[nathanielolin]

Addressed in PR #80