I have a dataframe I want to make predictions on from an SVM, but the dataframe doesn't have all of the levels that the original training dataframe did. Is there an easy way around this?
Here's a quick example
library(e1071)
df = data.frame(y = c(rep(1:3, each = 3)), x = rep(c("A", "B", "C"), each = 3))
m1 = svm(y ~ x, df)
df2 = data.frame(x = "B")
predict(m1, df2)
Error in `contrasts<-`(`*tmp*`, value = contr.funs[1 + isOF[nn]]) :
contrasts can be applied only to factors with 2 or more levels