How can I plot categories and sub-categories in a bar graph?

Hello!

I was wondering how to plot different categories and sub-categories in a bar plot. I did represent one of the categories (Category_1). Now, I would like to plot the second category ("Category 2") in exactly the same way, but leaving some space between both categories, with exactly the same subcategories (120,150,175 and so on).

I would also like to know if there is a way to place the category name in the x-axis and the sub-category name at the top of each bar column.

This is the code I have implemented to get the graph:

categories = categorical({'120','150','175','200','250'});

cat1_120 = [5 6 7 8 9];

cat1_150 = [4 5 7 8 9];

cat1_175 = [3 2 4 5 6];

cat1_200 = [1 2 2 3 4];

cat1_250 = [1 2 1 2 3];

Category_1 = [cat1_120; cat1_150; cat1_175; cat1_200; cat1_250];

bar(categories,Category_1,1,'stacked')

Thanks in advance!!

Answer 1

[Samayochita]

Hi Inés Encabo,

You can achieve this using MATLAB's “tiledlayout”(https://www.mathworks.com/help/matlab/ref/tiledlayout.html) for plotting both the categories side by side, ensuring space between them. Also, you can customize the x-axis labels and place sub-category names at the top of each bar using “text” function. You can remove the x-axis labels (120, 150, etc.) by setting “xticklabels({})”.

The below code implements exactly this:

% Define categories and subcategories 
categories = categorical({'120°C', '150°C', '175°C', '200°C', '250°C'}); 
cat1_120 = [5 6 7 8 9]; 
cat1_150 = [4 5 7 8 9]; 
cat1_175 = [3 2 4 5 6]; 
cat1_200 = [1 2 2 3 4]; 
cat1_250 = [1 2 1 2 3]; 
% Data for Category 1 
Category_1 = [cat1_120; cat1_150; cat1_175; cat1_200; cat1_250]; 
% Data for Category 2 (modify values to distinguish) 
Category_2 = Category_1 + 2;  
% Create tiled layout for side-by-side plots 
t = tiledlayout(1,2, 'TileSpacing', 'compact', 'Padding', 'compact'); 
% Plot Category 1 
nexttile; 
b1 = bar(categories, Category_1, 1, 'stacked'); 
ylabel('SIC - Specific Investment Cost (S/kW)'); 
xlabel('Category 1'); 
xticklabels({}); % Remove x-axis labels 
% Add labels on top of bars 
for i = 1:length(categories) 
    y_pos = sum(Category_1(i,:)); % Top of stacked bar 
    text(categories(i), y_pos + 1, string(categories(i)), ... 
        'HorizontalAlignment', 'center'); 
end 
% Plot Category 2 
nexttile; 
b2 = bar(categories, Category_2, 1, 'stacked'); 
ylabel('SIC - Specific Investment Cost (S/kW)'); 
xlabel('Category 2'); 
xticklabels({}); % Remove x-axis labels 
% Add labels on top of bars 
for i = 1:length(categories) 
    y_pos = sum(Category_2(i,:)); 
    text(categories(i), y_pos + 1, string(categories(i)), ... 
        'HorizontalAlignment', 'center'); 
end 

Hope this helps!