Hey guys, I have a x row by 3 column matrix (its big and the amount of rows varies). I want to... ...Keep ONLY pairs of rows with the same value in their first column and delete the rest. Meaning if a row has a unique first column value or if three rows have the same value in their first column, they should be deleted. I think this is pretty simple but I have read and looked for hours and just could not figure it out. Any help would be greatly appreciated! I attached some sample matrix. Thanks in advanced!