I am performing a LOOCV linear model and I got the parameters R2 and RMSE, but I was wondering if there is a way to calculate the standard deviation of the model R2. I tried to do it in the same way I do it for k-fold cross-validation but it does not work.
This is my model
train.control <- trainControl(method = "LOOCV") model_amb <- train(rate ~ volume, data = data_amb, method = "lm", trControl = train.control) summary(model_amb) sd(model_amb$resample$Rsquared)
This is what I get when I run the last line
sd(model_amb$resample$Rsquared)  NA