Check all data frames use factors

[hadley]

e.g. flights

[nicholasjhorton]

dest, origin, carrier, and tailnum are defined as chr in the flights table.

But why make them all factors? Why not change the "name" variable in the "airlines" table to character?

[hadley]

I don't know why I thought this was a good idea anymore :/

[nicholasjhorton]

Note that the current setup yields a warning (since airlines uses factors) when you run:

require(nycflights13)
sfoflights <- inner_join(filter(flights, dest=="SFO"), airlines)
Joining by: "carrier"
Warning message:
joining character vector and factor, coercing into character vector

[hadley]

Oh bummer, thanks for pointing that out.