Cell vs. Structure Arrays

This example compares cell and structure arrays, and shows how to store data in each type of array. Both cell and structure arrays allow you to store data of different types and sizes.

Structure Arrays

Structure arrays contain data in fields that you access by name.

For example, store patient records in a structure array.

patient(1).name = 'John Doe';
patient(1).billing = 127.00;
patient(1).test = [79, 75, 73; 180, 178, 177.5; 220, 210, 205];

patient(2).name = 'Ann Lane';
patient(2).billing = 28.50;
patient(2).test = [68, 70, 68; 118, 118, 119; 172, 170, 169];

patient

patient=1×2 struct array with fields:
    name
    billing
    test

Create a bar graph of the test results for each patient.

numPatients = numel(patient);
for p = 1:numPatients
   figure
   bar(patient(p).test)
   title(patient(p).name)
   xlabel('Test')
   ylabel('Result')
end

Cell Arrays

Cell arrays contain data in cells that you access by numeric indexing. Common applications of cell arrays include storing separate pieces of text and storing heterogeneous data from spreadsheets.

For example, store temperature data for three cities over time in a cell array.

temperature(1,:) = {'2009-12-31', [45, 49, 0]};
temperature(2,:) = {'2010-04-03', [54, 68, 21]};
temperature(3,:) = {'2010-06-20', [72, 85, 53]};
temperature(4,:) = {'2010-09-15', [63, 81, 56]};
temperature(5,:) = {'2010-12-09', [38, 54, 18]};

temperature

temperature=5×2 cell array
    {'2009-12-31'}    {[ 45 49 0]}
    {'2010-04-03'}    {[54 68 21]}
    {'2010-06-20'}    {[72 85 53]}
    {'2010-09-15'}    {[63 81 56]}
    {'2010-12-09'}    {[38 54 18]}

Plot the temperatures for each city by date.

allTemps = cell2mat(temperature(:,2));
dates = datetime(temperature(:,1));

plot(dates,allTemps)
title('Temperature Trends for Different Locations')
xlabel('Date')
ylabel('Degrees (Fahrenheit)')

Other Container Arrays

Struct and cell arrays are the most commonly used containers for storing heterogeneous data. Tables are convenient for storing heterogeneous column-oriented or tabular data. Alternatively, use map containers, or create your own class.