number, date, boolean or text data
entropy(T.a : ‘a) 🡒 number, aggregator
Returns the Shannon Entropy of the group. The value is returned expressed in shannons. The entropy of an empty group is 0. Supported data types are
table T = with [| as A, as B, as C, as D |] [| 0, "a", date(2020, 1, 8) , true |] [| 1, "a", date(2010, 9, 1) , true |] [| 1, "b", date(2019, 12, 1), true |] show summary "" a1b4 with entropy(T.A) entropy(T.B) entropy(T.C) entropy(T.D)
The entropy of an empty group is 0.
entropy aggregator is typically intended to identify the columns of input files with little or no information.