Structure Arrays in MATLAB

Notes on Structure Arrays in MATLAB

A structure array (struct array) is a data type where each element is a structure with named fields, ideal for organizing heterogeneous data (e.g., records with mixed types).

Key Features

• Fields accessed via dot notation: struct.field or struct(index).field.
• All elements must have the same fields.
• Can be 1D (row/column) or multidimensional.

Basic Operations

1. Create Single Struct:
   matlab

   MATLABCopy

   s.name = 'Alice';
   s.age = 30;
   s.height = 1.65;

2. Build Struct Array:
   matlab

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   data(1) = s;
   % First element data(2).name = 'Bob';
   data(2).age = 45;
   data(2).height = 1.80;

3. Efficient Creation:
   matlab

   MATLABCopy

   names = {'Alice', 'Bob', 'Charlie'};
   ages = [30; 45; 28];
   data = struct('name', names, 'age', ages, 'height', {1.65, 1.80, 1.70});

4. Access Data:
   matlab

   MATLABCopy

   data(1).name         % 'Alice' [data.age]           % [30 45 28] data([1 3]).height   % Heights of 1st and 3rd

5. Useful Functions:
   • fieldnames(data) → list fields
   • rmfield(data, 'age') → remove field
   • struct2table(data) → convert to table (preferred for tabular data)
   • isfield(data, 'name') → check field existence

Tips

• Use tables instead for large datasets (better performance and display).
• Great for grouped data like experiments, configurations, or object collections.