Quickly remove zero variance variables from a data.frame

Question

I have a large data.frame that was generated by a process outside my control, which may or may not contain variables with zero variance (i.e. all the observations are the sa

Answer 1

You may also want to look into the nearZeroVar() function in the caret package.

If you have one event out of 1000, it might be a good idea to discard these data (but this depends on the model). nearZeroVar() can do that.