8.3: Review- Homogeneous and Heterogeneous Data

An ordinary MATLAB array is usually homogeneous. Homogeneous means that all elements in the array have the same general type. For example, the following vector is a numeric array because every value is numeric:

scores = [87 92 78 95 88]

Likewise, this string array stores text values:

days = ["Monday" "Tuesday" "Wednesday"]

A heterogeneous collection contains different types of information together. For example, a student record may include a first name, a last name, a student ID number, and a GPA. That is a mix of text and numbers. MATLAB provides several ways to work with heterogeneous data. In this chapter we focus on:

• Cell arrays
• Structures
• Arrays of structures
• Tables

The table below summarizes the typical uses and examples of each data type.

Data organization	Typical use	Example
Numeric array	Same type of numeric data	Temperatures, forces, voltages
String array	Same type of text data	Names of cities or files
Cell array	Mixed data stored by position	A row containing ID, make, model, mileage
Structure	Mixed data stored by field name	student.FirstName, student.ID, student.GPA
Structure array	Many similar records	One structure per student, car, part, or sensor
Table	Mixed data stored by named columns	Spreadsheet-style data such as student records or lab measurements

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