TakeSmallestBy

TakeSmallestBy[data,f,n] gives the n elements ei in data for which f[ei] is smallest, sorted in ascending order.

TakeSmallestBy[data->prop,f,n] gives the property prop for the n elements in data for which f[ei] is smallest.

TakeSmallestBy[data,f,n,p] uses the ordering function p for sorting.

TakeSmallestBy[f,n] represents an operator form of TakeSmallestBy that can be applied to an expression. 

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