tech.tablesaw.aggregate

Class Summarizer

java.lang.Object

tech.tablesaw.aggregate.Summarizer

public class Summarizer
extends Object

Summarizes the data in a table, by applying functions to a subset of its columns.

How to use:

1. Create an instance providing a source table, the column or columns to summarize, and a function or functions to apply 2. Applying the functions to the designated columns, possibly creating subgroup summaries using one of the by() methods

Constructor Summary

Constructors

Constructor and Description
Summarizer(Table sourceTable, Column<?> column, AggregateFunction<?,?>... functions) Returns an object capable of summarizing the given column in the given sourceTable, by applying the given functions
Summarizer(Table sourceTable, Column<?> column1, Column<?> column2, AggregateFunction<?,?>... functions) Returns an object capable of summarizing the given columns in the given sourceTable, by applying the given functions
Summarizer(Table sourceTable, Column<?> column1, Column<?> column2, Column<?> column3, AggregateFunction<?,?>... functions) Returns an object capable of summarizing the given column2 in the given sourceTable, by applying the given functions
Summarizer(Table sourceTable, Column<?> column1, Column<?> column2, Column<?> column3, Column<?> column4, AggregateFunction<?,?>... functions) Returns an object capable of summarizing the given columns in the given sourceTable, by applying the given functions
Summarizer(Table sourceTable, List<String> columnNames, AggregateFunction<?,?>... functions) Returns an object capable of summarizing the given column in the given sourceTable, by applying the given functions

Method Summary

Modifier and Type	Method and Description
Table	apply() Returns the result of applying to the functions to all the values in the appropriate column TODO add a test that uses a non numeric return type with apply
Table	by(CategoricalColumn<?>... columns)
Table	by(int step) Returns a summary of the records grouped into subsets of the same size, in the order they appear
Table	by(String... columnNames)
Table	by(String groupNameTemplate, int step) Deprecated. Use by(step) instead.
Summarizer	groupBy(CategoricalColumn<?>... columns)
Summarizer	groupBy(int step)
Summarizer	groupBy(String... columnNames)
Table	having(Function<Table,Selection> selection)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Summarizer

public Summarizer(Table sourceTable,
                  Column<?> column,
                  AggregateFunction<?,?>... functions)

Returns an object capable of summarizing the given column in the given sourceTable, by applying the given functions

Summarizer

public Summarizer(Table sourceTable,
                  List<String> columnNames,
                  AggregateFunction<?,?>... functions)

Returns an object capable of summarizing the given column in the given sourceTable, by applying the given functions

Summarizer

public Summarizer(Table sourceTable,
                  Column<?> column1,
                  Column<?> column2,
                  AggregateFunction<?,?>... functions)

Returns an object capable of summarizing the given columns in the given sourceTable, by applying the given functions

Summarizer

public Summarizer(Table sourceTable,
                  Column<?> column1,
                  Column<?> column2,
                  Column<?> column3,
                  Column<?> column4,
                  AggregateFunction<?,?>... functions)

Returns an object capable of summarizing the given columns in the given sourceTable, by applying the given functions

Summarizer

public Summarizer(Table sourceTable,
                  Column<?> column1,
                  Column<?> column2,
                  Column<?> column3,
                  AggregateFunction<?,?>... functions)

Returns an object capable of summarizing the given column2 in the given sourceTable, by applying the given functions

Method Detail

by

public Table by(String... columnNames)

by

public Table by(CategoricalColumn<?>... columns)

by

@Deprecated
public Table by(String groupNameTemplate,
                            int step)

Deprecated. Use by(step) instead.

Returns a summary of the records grouped into subsets of the same size, in the order they appear

All groups have the same number of records. If the final group has fewer than step records it is dropped.

Parameters:

groupNameTemplate - a prefix for the group name

step - the number or records to include in each group

by

public Table by(int step)

Returns a summary of the records grouped into subsets of the same size, in the order they appear

All groups have the same number of records. If the final group has fewer than step records it is dropped.

Parameters:

step - the number or records to include in each group

apply

public Table apply()

Returns the result of applying to the functions to all the values in the appropriate column TODO add a test that uses a non numeric return type with apply

having

public Table having(Function<Table,Selection> selection)

groupBy

public Summarizer groupBy(CategoricalColumn<?>... columns)

groupBy

public Summarizer groupBy(String... columnNames)

groupBy

public Summarizer groupBy(int step)