typeof applied to a factor always seems to return "integer", independently of the type of the levels. This has a strange side effect. When a variable is "imported" into a data frame, its type changes. character variables automatically are converted to factors when imported into data frames.
Here is an example:
> v1<-1:3
> v2<-c("a","b","c")
> df<-data.frame(v1,v2)
> typeof(v2)
[1] "character"
> typeof(df$v2)
[1] "integer"It is somewhat surprising that the types of v2 and df$v2 are different.
the answer is to do levels(df$v2)[df$v2] but that is somewhat involved.
Should the types not be identical, and typeof applied to factors return the type of the levels?
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