Set Operations

Unions, intersection, set membership

Set operations compare the elements in two sets to find commonalities or differences. In MATLAB^®, the sets can be arrays of numbers, dates, times, tables, timetables, or text data.

Most set operations compare sets for exact equality, which can be problematic in the context of floating-point arithmetic. For that reason, the ismembertol and uniquetol functions are also available to perform comparisons with a tolerance.

Functions

`intersect`	Intersection of two sets of data
`ismember`	Find set members of data
`setdiff`	Difference of two sets of data
`setxor`	Exclusive OR of two sets of data
`union`	Union of two sets of data
`unique`	Unique values
`ismembertol`	Find set members of data within tolerance
`uniquetol`	Unique values within tolerance
`join`	Combine two tables or timetables by rows using key variables
`innerjoin`	Inner join between two tables or timetables
`outerjoin`	Outer join between two tables or timetables

Topics

Average Similar Data Points Using a Tolerance
This example shows how to average a group of points that are within tolerance. This approach produces a reduced data set that still holds the general shape of the original data.
Group Scattered Data Using a Tolerance
This example shows how to group scattered data points based on their proximity to points of interest.