Package tech.tablesaw.api

Interface CategoricalColumn<T>

All Superinterfaces:

Column<T>, Comparator<T>, Iterable<T>

All Known Implementing Classes:

BooleanColumn, DateColumn, DateTimeColumn, InstantColumn, IntColumn, LongColumn, ShortColumn, StringColumn, TimeColumn

public interface CategoricalColumn<T>
extends Column<T>

A column type that can be summarized, or serve as a grouping variable in cross tabs or other aggregation operations.

The column data is generally discrete, however NumberColumn implements CategoricalColumn so that it can be used to summarize when it contains ints. If you use it to summarize over a large range of floating point numbers, you will likely run out of memory.

Supporting subtypes include: - StringColumn - BooleanColumn - DateColumn, - etc

DateTimeColumn is not included. TimeColumn can be converted to ints without loss of data, so it does implement this interface

Method Summary

Modifier and Type	Method	Description
default Table	countByCategory()	Returns a count of the number of elements in each category (i.e., the number of repetitions of each value) TODO: This needs to be well tested, especially for IntColumn

Methods inherited from interface tech.tablesaw.columns.Column

allMatch, anyMatch, append, append, append, appendCell, appendCell, appendMissing, appendObj, asBytes, asList, asObjectArray, asSet, asStringColumn, byteSize, clear, columnWidth, contains, copy, count, count, countMissing, countUnique, emptyCopy, emptyCopy, equals, filter, first, get, getString, getUnformattedString, indexOf, inRange, interpolate, isEmpty, isMissing, isMissing, isNotMissing, lag, last, lastIndexOf, lead, map, map, mapInto, max, max, min, min, name, noneMatch, parser, print, reduce, reduce, removeMissing, rolling, rowComparator, sampleN, sampleX, set, set, set, set, set, set, setMissing, setMissingTo, setName, setParser, size, sortAscending, sortDescending, sorted, subset, summary, title, type, unique, valueHash, where

Methods inherited from interface java.util.Comparator

compare, equals, reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Methods inherited from interface java.lang.Iterable

forEach, iterator, spliterator

Method Detail

countByCategory

default Table countByCategory()

Returns a count of the number of elements in each category (i.e., the number of repetitions of each value) TODO: This needs to be well tested, especially for IntColumn