How to remove NA from a factor variable (and from a ggplot chart)?

Question

I have a problem with NA in a factor variable since ggplot includes them in the plot as if they are another category/level. I would like to drop the missing data. I am sorry

Answer 1

I'd use qplot instead of ggplot in this way:

qplot(x=column, data=subset(dataframe,!is.na(column)))

I hope this helps.