A dataframe whose value is a (column-wise) subset of another dataframes. The subset will be re-run as needed to reflect changes in the source dataframe; evaluation is lazy. The subset will be eN["x_dataframe"][cols]. Is a setting_user.

some_dfm set_df x_dataframe

Indicate that the source dataframe should be eN["x_dataframe"].

Setting name: x

some_dfn set_columns cols...

Indicate that cols are the required columns. Needs quotations marks around item(s); multiple items should be in c() format.

Setting name: x_column