This is not a simple removal of duplicates- I want to remove duplicate rows by their value matched in 2 columns- in 1 column, there are the unique clinic ids, in the other are the year of diagnosis of a disease. i want to apply the condotion that duplicates for a unique clinic id (ie patient) should be removed if the corresponding years of diagnosis are within a year of each other. any provision for such a thing in jmp? eg, a diagnosis in 2015 and 2016 should be considered as one, and the year 2015 should be retained. i have tried the join and summary options without success. any ideas?