CountDistinctBy

CountDistinctBy[{e1,e2,},f]

gives the number of distinct values of f[ei] that occur.

CountDistinctBy[f]

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

Details

Examples

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Basic Examples  (2)

Count the number of distinct first parts:

Count the number of distinct first parts of the values of an association:

Use the operator form of CountDistinctBy:

Applications  (1)

Extract the words that occur in the text of Alice in Wonderland:

Count the number of distinct words, ignoring case:

Properties & Relations  (1)

CountDistinctBy[list,f] gives the same result as CountDistinct[f/@list]:

Introduced in 2014
 (10.0)