I have an Explorer.DataFrame, like so. df = DataFrame.new( goal: Enum.to_list(60..1) |> Series.from_list() ) df = DataFrame.put(df, :day_of_week, Explorer.Series.transform(Series.subtract(df["day"], 1), &get_day_of_week/1)) Simple enough. But now I need to create another column that relies on t…

You could use Series.select to implement what you’re describing: Series.select( Series.equal(df["day_of_week"], 1) Series.multiply(df["goal"], 3), Series.multiply(df["goal"], 6) )