I am running a random forest model with cforest function, as you can see the below is result of the model that runs fine. After this, I ran the varimp() function setting default conditional= FALSE which runs, however when I try to run the same function with parameter conditional =TRUE. I am getting the following error:
> caret:::cforestStats(RF1) RMSE Rsquared MAE 19.0656593 0.2217984 15.7459980
> RF1.coef <- varimp(RF1, conditional = TRUE, threshold = .3) Error in terms.formula(formula, data = data) : invalid model formula in ExtractVars
Please suggest what can I do to fix this issue.