Finding 3 largest values out of a set
I need to identify the 3 largest values out of a set of data grouping by certain columns, e.g. with Big Class, suppose I want to identify the 3 tallest students at each age for each sex. I don't think there are any ties/ambiguity in that set, but in my set there are, e.g. if the heights for a given age/sex combination were (64, 63, 61, 61, 61, 61), it doesn't matter which of the 61s is selected. ...