MATLAB Programming Fundamentals - MathWorks

Age: 38

Smoker: 1

BloodPressure: [124 93]

Fields in a structure array are analogous to variables in a table. However, unlike with

tables, you cannot enforce homogeneity within a field. For example, you can have some

values of S.Gender that are categorical array elements, Male or Female, others that are

character vectors, 'Male' or 'Female', and others that are integers, 0 or 1.

Now consider the same data stored in a scalar structure, with four fields each containing

one variable from the table.

ScalarStruct = struct(...

'Gender',{Gender},...

'Age',Age,...

'Smoker',Smoker,...

'BloodPressure',BloodPressure)

ScalarStruct = struct with fields:

Gender: [100x1 categorical]

Age: [100x1 double]

Smoker: [100x1 logical]

BloodPressure: [100x2 double]

Unlike with tables, you cannot enforce that the data is rectangular. For example, the field

ScalarStruct.Age can be a different length than the other fields.

A table allows you to maintain the rectangular structure (like a structure array) and

enforce homogeneity of variables (like fields in a scalar structure). Although cell arrays do

not have named fields, they have many of the same disadvantages as structure arrays and

scalar structures. If you have rectangular data that is homogeneous in each variable,

consider using a table. Then you can use numeric or named indexing, and you can use

table properties to store metadata.

Access Data Using Numeric or Named Indexing

You can index into a table using parentheses, curly braces, or dot indexing. Parentheses

allow you to select a subset of the data in a table and preserve the table container. Curly

braces and dot indexing allow you to extract data from a table. Within each table indexing

method, you can specify the rows or variables to access by name or by numeric index.

9 Tables