what does object 'parental' not found in R mean ?

Question

Hello ,

Im trying to check for constance of variance for residuals with boxplots . But when I ran the following expression in R I get this error . What is it aobut ?

  boxplot(split(model$res,parental))

Error in split.default(model$res, parental) : object 'parental' not found

Answer 1

It can't find the parental object that you're passing in. You're probably referencing a field name within a data frame. So you need to change your expression to be something like:

boxplot(split(model$res,data.frame.name[,"parental"]))