returns a list of the ei for which the value of f[ei] is maximal.


returns a list of the ei corresponding to the n largest f[ei].


represents an operator form of MaximalBy that can be applied to an expression.


  • Values of f[ei] are compared using the same canonical order as in Sort.
  • The maximal ei are returned in the order they appear in the input.
  • In the case of MaximalBy[list,f,n], the ei are sorted in the order of decreasing f[ei], with those having the same value of f[ei] being taken in the order they appear in list.
  • MaximalBy[list,f, UpTo[n]] gives n elements, or as many as are available.
  • MaximalBy[f][expr] is equivalent to MaximalBy[expr,f].


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Basic Examples  (4)

Find the maximal element by last part:

All maximal elements are returned, in order of appearance:

Obtain the first three maximal elements:

Obtain the first 4 maximal elements, or as many as are available:

Scope  (1)

MaximalBy works with symbolic expressions, using OrderedQ:

Possible Issues  (3)

The maximal element is determined using OrderedQ, not numerical ordering:

Introduced in 2014
Updated in 2015