- df-filter-rows df predicateprocedure
Returns a new data frame with only the rows for which predicate is true. predicate is called once per row with a row accessor: a one-argument function that, given a column key, returns that column's value in the current row.
(df-filter-rows df (lambda (get) (> (get 'age) 30)))Automatically picks between two strategies depending on df's row count (rebuilding row by row for small data, or marking matches with a bit vector for large data -- see *filter-strategy-threshold* below); both give identical results, so this is a performance detail.