I have a tall data table with sample ID, test, count, and some categorical info. The test column identifies which test the count refers to and whether it's a positive or negative population. For example "Test one positive", "test one negative", etc., as well as some rows such as "total tests". These repeat for each sample.
How would I select all the rows with a "positive" in the column regardless of which test ID is before it, so I can then subset them into a new data table?
